1.
Anatomical terminology
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Anatomical terminology is a form of scientific terminology used by anatomists, zoologists, and health professionals such as doctors. Anatomical terminology uses many terms, suffixes, and prefixes deriving from Ancient Greek. These terms can be confusing to those unfamiliar with them, but can be more precise reducing ambiguity, also, since these anatomical terms are not used in everyday conversation, their meanings are less likely to change, and less likely to be misinterpreted. By using precise anatomical terminology such ambiguity is eliminated, an international standard for anatomical terminology, Terminologia Anatomica has been created. Anatomical terminology has quite regular morphology, the prefixes and suffixes are used to add meanings to different roots. The root of a term refers to an organ, tissue. For example, in the disorder hypertension, the prefix hyper- means high or over, the roots, prefixes and suffixes are often derived from Greek or Latin, and often quite dissimilar from their English-language variants. Latin names of such as musculus biceps brachii can be split up and refer to, musculus for muscle, biceps for two-headed. The first word tells us what we are speaking about, the second describes it, when describing the position of anatomical structures, structures may be described according to the anatomical landmark they are near. These landmarks may include structures, such as the umbilicus or sternum, or anatomical lines, the cephalon or cephalic region refers to the head. This area is differentiated into the cranium, facies, frons, oculus, auris, bucca, nausus, oris. The neck area is called the cervicis or cervical region, examples of structures named according to this include the frontalis muscle, submental lymph nodes, buccal membrane and orbicularis oculi muscle. Sometimes, unique terminology is used to reduce confusion in different parts of the body, for example, different terms are used when it comes to the skull in compliance with its embryonic origin and its tilted position compared to in other animals. Here, Rostral refers to proximity to the front of the nose, similarly, in the arms, different terminology is often used in the arms, in part to reduce ambiguity as what is the front, back, inner and outer surfaces. For this reason, the terms below are used, Radial referring to the radius bone, ulnar referring to the ulna bone, medially positioned when in the standard anatomical position. Other terms are used to describe the movement and actions of the hands and feet. International morphological terminology is used by the colleges of medicine and dentistry and it facilitates communication and exchanges between scientists from different countries of the world and it is used daily in the fields of research, teaching and medical care. The international morphological terminology refers to morphological sciences as a biological sciences branch, in this field, the form and structure are examined as well as the changes or developments in the organism
2.
Organ (anatomy)
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In biology, an organ or viscus is a collection of tissues joined in a structural unit to serve a common function. In anatomy, a viscus is an organ, and viscera is the plural form. Organs are composed of main tissue, parenchyma, and sporadic tissues, the main tissue is that which is unique for the specific organ, such as the myocardium, the main tissue of the heart, while sporadic tissues include the nerves, blood vessels, and connective tissues. The main tissues that make up an organ tend to have common embryologic origins, functionally related organs often cooperate to form whole organ systems. Organs exist in all biological organisms, in particular they are not restricted to animals. In single-cell organisms like bacteria, the analogue of an organ is called organelle. A hollow organ is an organ that forms a hollow tube or pouch, such as the stomach or intestine, or that includes a cavity. Two or more organs working together in the execution of a specific body function form an organ system, the functions of organ systems often share significant overlap. For instance, the nervous and endocrine system both operate via an organ, the hypothalamus. For this reason, the two systems are combined and studied as the neuroendocrine system, the same is true for the musculoskeletal system because of the relationship between the muscular and skeletal systems. Mammals such as humans have a variety of organ systems and these specific systems are also widely studied in human anatomy. Cardiovascular system, pumping and channeling blood to and from the body and lungs with heart, digestive system, digestion and processing food with salivary glands, esophagus, stomach, liver, gallbladder, pancreas, intestines, colon, rectum and anus. Excretory system, kidneys, ureters, bladder and urethra involved in balance, electrolyte balance. Integumentary system, skin, hair and nails, nervous system, collecting, transferring and processing information with brain, spinal cord and nerves. Reproductive system, the sex organs, such as ovaries, fallopian tubes, uterus, vulva, vagina, testes, vas deferens, seminal vesicles, prostate, respiratory system, the organs used for breathing, the pharynx, larynx, trachea, bronchi, lungs and diaphragm. Skeletal system, structural support and protection with bones, cartilage, ligaments, the organ level of organisation in animals can be first detected in flatworms and the more advanced phyla. The less-advanced taxa do not show consolidation of their tissues into organs, the study of plant organs is referred to as plant morphology, rather than anatomy, as in animal systems. Organs of plants can be divided into vegetative and reproductive, vegetative plant organs are roots, stems, and leaves
3.
Muscular system
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The muscular system is an organ system consisting of skeletal, smooth and cardiac muscles. It permits movement of the body, maintains posture, and circulates blood throughout the body, the muscular system in vertebrates is controlled through the nervous system, although some muscles can be completely autonomous. Together with the system it forms the musculoskeletal system, which is responsible for movement of the human body. There are three types of muscles, skeletal muscles, cardiac or heart muscles, and smooth muscles. Muscles provide strength, balance, posture, movement and heat for the body to keep warm, upon stimulation by an action potential, skeletal muscles perform a coordinated contraction by shortening each sarcomere. The best proposed model for understanding contraction is the sliding filament model of muscle contraction, within the sarcomere, actin and myosin fibers overlap in a contractile motion towards each other. Myosin filaments have club-shaped heads that project toward the actin filaments, larger structures along the myosin filament called myosin heads are used to provide attachment points on binding sites for the actin filaments. The myosin heads move in a style, they swivel toward the center of the sarcomere, detach. This is called a ratchet type drive system and this process consumes large amounts of adenosine triphosphate, the energy source of the cell. ATP binds to the bridges between myosin heads and actin filaments. The release of energy powers the swiveling of the myosin head, when ATP is used, it becomes adenosine diphosphate, and since muscles store little ATP, they must continuously replace the discharged ADP with ATP. Muscle tissue also contains a supply of a fast acting recharge chemical, creatine phosphate. Calcium ions are required for each cycle of the sarcomere, calcium is released from the sarcoplasmic reticulum into the sarcomere when a muscle is stimulated to contract. This calcium uncovers the actin binding sites, when the muscle no longer needs to contract, the calcium ions are pumped from the sarcomere and back into storage in the sarcoplasmic reticulum. There are approximately 639 skeletal muscles in the human body, at rest, the body produces the majority of its ATP aerobically in the mitochondria without producing lactic acid or other fatiguing byproducts. During exercise, the method of ATP production varies depending on the fitness of the individual as well as the duration, at lower activity levels, when exercise continues for a long duration, energy is produced aerobically by combining oxygen with carbohydrates and fats stored in the body. Aerobic training allows the delivery system to be more efficient. Recovery is very quick, with full creatine stores regenerated within five minutes, heart muscles are distinct from skeletal muscles because the muscle fibers are laterally connected to each other
4.
Human skeleton
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The human skeleton is the internal framework of the body. It is composed of around 300 bones at birth – this total decreases to 206 bones by adulthood after some bones have fused together, the bone mass in the skeleton reaches maximum density around age 20. The human skeleton can be divided into the skeleton and the appendicular skeleton. The axial skeleton is formed by the column, the rib cage. The appendicular skeleton, which is attached to the skeleton, is formed by the shoulder girdle, the pelvic girdle. The human skeleton performs six major functions, support, movement, protection, production of cells, storage of minerals. The human skeleton is not as sexually dimorphic as that of other primate species. In general, female skeletal elements tend to be smaller and less robust than corresponding male elements within a given population, the human female pelvis is also different from that of males in order to facilitate child birth. Unlike most primates, human males do not have penile bones, the axial skeleton is formed by the vertebral column, a part of the rib cage, and the skull. The upright posture of humans is maintained by the skeleton, which transmits the weight from the head, the trunk. The bones of the spine are supported by many ligaments, the erector spinae muscles are also supporting and are useful for balance. The appendicular skeleton is formed by the pectoral girdles, the limbs, the pelvic girdle or pelvis. Their functions are to make locomotion possible and to protect the organs of digestion, excretion and reproduction. The skeleton serves six major functions, support, movement, protection, production of cells, storage of minerals. The skeleton provides the framework which supports the body and maintains its shape, the pelvis, associated ligaments and muscles provide a floor for the pelvic structures. Without the rib cages, costal cartilages, and intercostal muscles, the joints between bones allow movement, some allowing a wider range of movement than others, e. g. the ball and socket joint allows a greater range of movement than the pivot joint at the neck. Movement is powered by muscles, which are attached to the skeleton at various sites on bones. Muscles, bones, and joints provide the principal mechanics for movement and it is believed that the reduction of human bone density in prehistoric times reduced the agility and dexterity of human movement
5.
Cartilage
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It is not as hard and rigid as bone, but it is stiffer and less flexible than muscle. Because of its rigidity, cartilage often serves the purpose of holding tubes open in the body, cartilage is classified in three types, elastic cartilage, hyaline cartilage and fibrocartilage, which differ in relative amounts of collagen and proteoglycan. Cartilage does not contain blood vessels or nerves, nutrition is supplied to the chondrocytes by diffusion. The compression of the cartilage or flexion of the elastic cartilage generates fluid flow. Compared to other tissues, cartilage has a very slow turnover of its extracellular matrix. In embryogenesis, the system is derived from the mesoderm germ layer. Following the initial chondrification that occurs during embryogenesis, cartilage growth consists mostly of the maturing of immature cartilage to a mature state. The division of cells within cartilage occurs very slowly, and thus growth in cartilage is not based on an increase in size or mass of the cartilage itself. The articular cartilage function is dependent on the composition of the extracellular matrix. The ECM consists mainly of proteoglycan and collagens, the main proteoglycan in cartilage is aggrecan, which, as its name suggests, forms large aggregates with hyaluronan. These aggregates are negatively charged and hold water in the tissue, the collagen, mostly collagen type II, constrains the proteoglycans. The ECM responds to tensile and compressive forces that are experienced by the cartilage, cartilage growth thus refers to the matrix deposition, but can also refer to both the growth and remodeling of the extracellular matrix. Due to the stress on the patellofemoral joint during resisted knee flexion. The mechanical properties of articular cartilage in load bearing joints such as knee and hip have been studied extensively at macro, micro and these mechanical properties include the response of cartilage in frictional, compressive, shear and tensile loading. Cartilage is resilient and displays viscoelastic properties, lubricin, a glycoprotein abundant in cartilage and synovial fluid, plays a major role in bio-lubrication and wear protection of cartilage. Cartilage has limited capabilities, Because chondrocytes are bound in lacunae. Therefore, cartilage damage is difficult to heal, also, because hyaline cartilage does not have a blood supply, the deposition of new matrix is slow. Damaged hyaline cartilage is replaced by fibrocartilage scar tissue
6.
Tendon
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A tendon or sinew is a tough band of fibrous connective tissue that usually connects muscle to bone and is capable of withstanding tension. Tendons are similar to ligaments, both are made of collagen, ligaments join one bone to another bone, while tendons connect muscle to bone. Histologically, tendons consist of dense connective tissue fascicles encased in dense irregular connective tissue sheaths. Normal healthy tendons are composed mostly of parallel arrays of collagen fibers closely packed together, the collagen portion is made up of 97–98% type I collagen, with small amounts of other types of collagen. After secretion from the cell, the peptides are cleaved by procollagen N- and C-proteinases. A collagen molecule is about 300 nm long and 1–2 nm wide, and the diameter of the fibrils that are formed can range from 50–500 nm. In tendons, the fibrils then assemble further to form fascicles, which are about 10 mm in length with a diameter of 50–300 μm, fascicles are bound by the endotendineum, which is a delicate loose connective tissue containing thin collagen fibrils. and elastic fibres. Groups of fascicles are bounded by the epitenon, filling the interstitia within the fascia where the tendon is located is the paratenon a fatty areolar tissue. The major GAG components of the tendon are dermatan sulfate and chondroitin sulfate, the dermatan sulfate side chains of decorin aggregate in solution, and this behavior can assist with the assembly of the collagen fibrils. The tenocytes produce the collagen molecules, which aggregate end-to-end and side-to-side to produce collagen fibrils, fibril bundles are organized to form fibres with the elongated tenocytes closely packed between them. There is a network of cell processes associated with collagen in the tendon. The cells communicate with other through gap junctions, and this signalling gives them the ability to detect. Blood vessels may be visualized within the endotendon running parallel to collagen fibres, the internal tendon bulk is thought to contain no nerve fibres, but the epitenon and paratenon contain nerve endings, while Golgi tendon organs are present at the junction between tendon and muscle. Tendon length varies in all groups and from person to person. Tendon length is, in practice, the deciding factor regarding actual and potential muscle size, successful bodybuilders will generally have shorter tendons. Conversely, in sports requiring athletes to excel in such as running or jumping, it is beneficial to have longer than average Achilles tendon. Traditionally, tendons have been considered to be a mechanism by which muscles connect to bone and this connection allows tendons to passively modulate forces during locomotion, providing additional stability with no active work. However, over the past two decades, much research focused on the properties of some tendons and their ability to function as springs
7.
Ligament
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In anatomy, a ligament is the fibrous connective tissue that connects bones to other bones and is also known as articular ligament, articular larua, fibrous ligament, or true ligament. Ligament can also refer to, Peritoneal ligament, a fold of peritoneum or other membranes, fetal remnant ligament, the remnants of a fetal tubular structure. Periodontal ligament, a group of fibers that attach the cementum of teeth to the alveolar bone. The study of ligaments is known as desmology, ligaments are similar to tendons and fasciae as they are all made of connective tissue. The differences in them are in the connections that they make, ligaments connect one bone to bone, tendons connect muscle to bone. These are all found in the system of the human body. Ligament most commonly refers to a band of dense connective tissue bundles made of collagenous fibers. Ligaments connect bones to other bones to form joints, while tendons connect bone to muscle, some ligaments limit the mobility of articulations, or prevent certain movements altogether. Capsular ligaments are part of the capsule that surrounds synovial joints. Extra-capsular ligaments join together in harmony with the other ligaments and provide joint stability, intra-capsular ligaments, which are much less common, also provide stability but permit a far larger range of motion. Cruciate ligaments are paired ligaments in the form of a cross and they gradually strain when under tension, and return to their original shape when the tension is removed. However, they retain their original shape when extended past a certain point or for a prolonged period of time. This is one reason why dislocated joints must be set as quickly as possible, if the ligaments lengthen too much, then the joint will be weakened, athletes, gymnasts, dancers, and martial artists perform stretching exercises to lengthen their ligaments, making their joints more supple. The term hypermobility refers to people with more-elastic ligaments, allowing their joints to stretch and contort further, the consequence of a broken ligament can be instability of the joint. Not all broken ligaments need surgery, but, if surgery is needed to stabilise the joint, if it is not possible to fix the broken ligament, other procedures such as the Brunelli procedure can correct the instability. Instability of a joint can over time lead to wear of the cartilage, one of the most often torn ligaments in the body is the anterior cruciate ligament. The ACL is one of the ligaments crucial to stability and persons who tear their ACL often seek to undergo reconstructive surgery. One of these techniques is the replacement of the ligament with an artificial material, an artificial ligament is a reinforcing material that is used to replace a torn ligament, such as the ACL
8.
Joint
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A joint or articulation is the connection made between bones in the body which link the skeletal system into a functional whole. They are constructed to allow for different degrees and types of movement, other joints such as sutures between the bones of the skull permit very little movement in order to protect the brain and the sense organs. The connection between a tooth and the jawbone is also called a joint, and is described as a fibrous joint known as a gomphosis, joints are classified both structurally and functionally. Joints are mainly classified structurally and functionally, structural classification is determined by how the bones connect to each other, while functional classification is determined by the degree of movement between the articulating bones. In practice, there is significant overlap between the two types of classifications, a facet joint is the joint between two articular processes between two vertebrae. Structural classification names and divides joints according to the type of binding tissue that connects the bones to each other, joints can also be classified functionally according to the type and degree of movement they allow, Joint movements are described with reference to the basic anatomical planes. Synarthrosis – permits little or no mobility, most synarthrosis joints are fibrous joints. Most amphiarthrosis joints are cartilaginous joints, Synovial joints can in turn be classified into six groups according to the type of movement they allow, plane joint, ball and socket joint, hinge joint, pivot joint, condyloid joint and saddle joint. Joints can also be classified, according to the number of axes of movement they allow, another classification is according to the degrees of freedom allowed, and distinguished between joints with one, two or three degrees of freedom. A further classification is according to the number and shapes of the surfaces, flat, concave. Types of articular surfaces include trochlear surfaces, joints can also be classified based on their anatomy or on their biomechanical properties. Swimming is a way to exercise the joints with minimal damage. A joint disorder is termed arthropathy, and when involving inflammation of one or more joints the disorder is called arthritis, most joint disorders involve arthritis, but joint damage by external physical trauma is typically not termed arthritis. Arthropathies are called polyarticular when involving many joints and monoarticular when involving only a single joint, arthritis is the leading cause of disability in people over the age of 55. There are many different forms of arthritis, each of which has a different cause, furthermore, there is emerging evidence that abnormal anatomy may contribute to early development of osteoarthritis. Other forms of arthritis are rheumatoid arthritis and psoriatic arthritis, which are diseases in which the body is attacking itself. Septic arthritis is caused by joint infection, gouty arthritis is caused by deposition of uric acid crystals in the joint that results in subsequent inflammation. Additionally, there is a common form of gout that is caused by the formation of rhomboidal-shaped crystals of calcium pyrophosphate
9.
Connective tissue
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Connective tissue is one of the four types of biological tissue that supports, connects or separates different types of tissues and organs in the body. The other three types are epithelial, muscle, and nervous tissue, Connective tissue is found in between other tissues everywhere in the body, including the nervous system. In the central system, the three outer membranes that envelop the brain and spinal cord are composed of connective tissue. All connective tissue consists of three components, fibers, ground substance and cells. Blood and lymph lack the fiber component, all are immersed in the body water. The cells of connective tissue include fibroblasts, adipocytes, macrophages, mast cells, Connective tissue can be broadly subdivided into connective tissue proper, and special connective tissue. Connective tissue proper consists of connective tissue and dense connective tissue Special connective tissue consists of reticular connective tissue, adipose tissue, cartilage, bone. Other kinds of connective tissues include fibrous, elastic, and lymphoid connective tissues, new vascularised connective tissue that forms in the process of wound healing is termed granulation tissue. Fibroblasts are the responsible for the production of some CT. Type I collagen, is present in forms of connective tissue. Characteristics of CT, Cells are spread through an extracellular fluid, ground substance - A clear, colorless, and viscous fluid containing glycosaminoglycans and proteoglycans to fix the body water and the collagen fibers in the intercellular spaces. Ground substance slows the spread of pathogens, not all types of CT are fibrous. Examples of non-fibrous CT include adipose tissue and blood, adipose tissue gives mechanical cushioning to the body, among other functions. Although there is no dense collagen network in adipose tissue, groups of cells are kept together by collagen fibers. The matrix of blood is plasma, both the ground substance and proteins create the matrix for CT. Types of fibers, Connective tissue has a variety of functions that depend on the types of cells. They also allow organs to resist stretching and tearing forces, elastic fibers, made from elastin and fibrillin, also provide resistance to stretch forces. They are found in the walls of blood vessels and in certain ligaments
10.
Calcium
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Calcium is a chemical element with symbol Ca and atomic number 20. Calcium is a soft grayish-yellow alkaline earth metal, fifth-most-abundant element by mass in the Earths crust, the ion Ca2+ is also the fifth-most-abundant dissolved ion in seawater by both molarity and mass, after sodium, chloride, magnesium, and sulfate. Free calcium metal is too reactive to occur in nature, Calcium is produced in supernova nucleosynthesis. Calcium is a trace element in living organisms. It is the most abundant metal by mass in animals, and it is an important constituent of bone, teeth. In cell biology, the movement of the calcium ion into, Calcium carbonate and calcium citrate are often taken as dietary supplements. Calcium is on the World Health Organizations List of Essential Medicines, Calcium has a wide variety of applications, almost all of which are associated with calcium compounds and salts. Calcium metal is used as a deoxidizer, desulfurizer, and decarbonizer for production of ferrous and nonferrous alloys. In steelmaking and production of iron, Ca reacts with oxygen, Calcium carbonate is used in manufacturing cement and mortar, lime, limestone and aids in production in the glass industry. It also has chemical and optical uses as mineral specimens in toothpastes, Calcium hydroxide solution is used to detect the presence of carbon dioxide in a gas sample bubbled through a solution. The solution turns cloudy where CO2 is present, Calcium arsenate is used in insecticides. Calcium carbide is used to make acetylene gas and various plastics, Calcium chloride is used in ice removal and dust control on dirt roads, as a conditioner for concrete, as an additive in canned tomatoes, and to provide body for automobile tires. Calcium citrate is used as a food preservative, Calcium cyclamate is used as a sweetening agent in several countries. In the United States, it has been outlawed as a suspected carcinogen, Calcium gluconate is used as a food additive and in vitamin pills. Calcium hypochlorite is used as a swimming pool disinfectant, as an agent, as an ingredient in deodorant. Calcium permanganate is used in rocket propellant, textile production, as a water sterilizing agent. Calcium phosphate is used as a supplement for animal feed, fertilizer, in production for dough and yeast products, in the manufacture of glass. Calcium phosphide is used in fireworks, rodenticide, torpedoes, Calcium sulfate is used as common blackboard chalk, as well as, in its hemihydrate form, Plaster of Paris
11.
Phosphorus
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Phosphorus is a chemical element with symbol P and atomic number 15. As an element, phosphorus exists in two major forms—white phosphorus and red phosphorus—but because it is reactive, phosphorus is never found as a free element on Earth. At 0. 099%, phosphorus is the most abundant pnictogen in the Earths crust, with few exceptions, minerals containing phosphorus are in the maximally oxidised state as inorganic phosphate rocks. The glow of phosphorus itself originates from oxidation of the white phosphorus — a process now termed chemiluminescence, together with nitrogen, arsenic, antimony, and bismuth, phosphorus is classified as a pnictogen. Phosphates are a component of DNA, RNA, ATP, and the phospholipids, demonstrating the link between phosphorus and life, elemental phosphorus was first isolated from human urine, and bone ash was an important early phosphate source. Phosphate mines contain fossils, especially marine fossils, because phosphate is present in the deposits of animal remains. Low phosphate levels are an important limit to growth in aquatic systems. The vast majority of compounds produced are consumed as fertilisers. Phosphate is needed to replace the phosphorus that plants remove from the soil, other applications include the role of organophosphorus compounds in detergents, pesticides, and nerve agents. Phosphorus exists as several forms that exhibit different properties. The two most common allotropes are white phosphorus and red phosphorus, from the perspective of applications and chemical literature, the most important form of elemental phosphorus is white phosphorus, often abbreviated as WP. It is a soft and waxy solid consists of tetrahedral P4 molecules. This P4 tetrahedron is also present in liquid and gaseous phosphorus up to the temperature of 800 °C when it starts decomposing to P2 molecules, White phosphorus exists in two crystalline forms, α and β. At room temperature, the α-form is stable, which is common and it has cubic crystal structure and at 195.2 K, it transforms into β-form. These forms differ in terms of the orientations of the constituent P4 tetrahedra. White phosphorus is the least stable, the most reactive, the most volatile, the least dense, White phosphorus gradually changes to red phosphorus. This transformation is accelerated by light and heat, and samples of white phosphorus almost always some red phosphorus. For this reason, white phosphorus that is aged or otherwise impure is also called yellow phosphorus, when exposed to oxygen, white phosphorus glows in the dark with a very faint tinge of green and blue
12.
Haematopoiesis
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Haematopoiesis is the formation of blood cellular components. All cellular blood components are derived from stem cells. In a healthy person, approximately 1011–1012 new blood cells are produced daily in order to maintain steady state levels in the peripheral circulation. Haematopoietic stem cells reside in the medulla of the bone and have the ability to give rise to all of the different mature blood cell types and tissues. HSCs are self-renewing cells, when they proliferate, at least some of their daughter cells remain as HSCs, so the pool of stem cells is not depleted. This phenomenon is called asymmetric division. The other daughters of HSCs can follow any of the other pathways that lead to the production of one or more specific types of blood cell. The pool of progenitors is heterogeneous and can be divided into two groups, long-term self-renewing HSC and only transiently self-renewing HSC, also called short-terms and this is one of the main vital processes in the body. All blood cells are divided into three lineages, erythroid cells are the oxygen carrying red blood cells. Both reticulocytes and erythrocytes are functional and are released into the blood, in fact, a reticulocyte count estimates the rate of erythropoiesis. Lymphocytes are the cornerstone of the immune system. They are derived from common lymphoid progenitors, the lymphoid lineage is primarily composed of T-cells and B-cells. In developing embryos, blood formation occurs in aggregates of cells in the yolk sac. As development progresses, blood formation occurs in the spleen, liver, when bone marrow develops, it eventually assumes the task of forming most of the blood cells for the entire organism. However, maturation, activation, and some proliferation of lymphoid cells occurs in the spleen, thymus, in children, haematopoiesis occurs in the marrow of the long bones such as the femur and tibia. In adults, it mainly in the pelvis, cranium, vertebrae. In some cases, the liver, thymus, and spleen may resume their haematopoietic function and it may cause these organs to increase in size substantially. During fetal development, since bones and thus the bone marrow develop later, therefore, the liver is enlarged during development. In some vertebrates, haematopoiesis can occur wherever there is a loose stroma of connective tissue and slow blood supply, such as the gut, spleen or kidney
13.
Medical diagnosis
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Medical diagnosis is the process of determining which disease or condition explains a persons symptoms and signs. It is most often referred to as diagnosis with the context being implicit. The information required for diagnosis is typically collected from a history, often, one or more diagnostic procedures, such as diagnostic tests, are also done during the process. Sometimes Posthumous diagnosis is considered a kind of medical diagnosis, Diagnosis is often challenging, because many signs and symptoms are nonspecific. For example, redness of the skin, by itself, is a sign of many disorders, thus differential diagnosis, in which several possible explanations are compared and contrasted, must be performed. This involves the correlation of various pieces of information followed by the recognition and differentiation of patterns, occasionally the process is made easy by a sign or symptom that is pathognomonic. Diagnosis is a component of the procedure of a doctors visit. From the point of view of statistics, the procedure involves classification tests. The first recorded examples of medical diagnosis are found in the writings of Imhotep in ancient Egypt, a Babylonian medical textbook, the Diagnostic Handbook written by Esagil-kin-apli, introduced the use of empiricism, logic and rationality in the diagnosis of an illness or disease. Traditional Chinese Medicine, as described in the Yellow Emperors Inner Canon or Huangdi Neijing, specified four diagnostic methods, inspection, auscultation-olfaction, interrogation, hippocrates was known to make diagnoses by tasting his patients urine and smelling their sweat. This article uses diagnostician as any of these person categories, a diagnostic procedure does not necessarily involve elucidation of the etiology of the diseases or conditions of interest, that is, what caused the disease or condition. Such elucidation can be useful to optimize treatment, further specify the prognosis or prevent recurrence of the disease or condition in the future, the initial task is to detect a medical indication to perform a diagnostic procedure. Indications include, Detection of any deviation from what is known to be normal, such as can be described in terms of, for example, anatomy, physiology, pathology, psychology, a complaint expressed by a patient. The fact that a patient has sought a diagnostician can itself be an indication to perform a diagnostic procedure, even during an already ongoing diagnostic procedure, there can be an indication to perform another, separate, diagnostic procedure for another, potentially concomitant, disease or condition. A diagnostic test is any kind of medical test performed to aid in the diagnosis or detection of disease, Diagnostic tests can also be used to provide prognostic information on people with established disease. Processing of the answers, findings or other results, consultations with other providers and specialists in the field may be sought. There are a number of methods or techniques that can be used in a diagnostic procedure, in reality, a diagnostic procedure may involve components of multiple methods. The final result may also remain a list of possible conditions, the resultant diagnostic opinion by this method can be regarded more or less as a diagnosis of exclusion
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Human
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Modern humans are the only extant members of Hominina tribe, a branch of the tribe Hominini belonging to the family of great apes. Several of these hominins used fire, occupied much of Eurasia and they began to exhibit evidence of behavioral modernity around 50,000 years ago. In several waves of migration, anatomically modern humans ventured out of Africa, the spread of humans and their large and increasing population has had a profound impact on large areas of the environment and millions of native species worldwide. Humans are uniquely adept at utilizing systems of communication for self-expression and the exchange of ideas. Humans create complex structures composed of many cooperating and competing groups, from families. Social interactions between humans have established a wide variety of values, social norms, and rituals. These human societies subsequently expanded in size, establishing various forms of government, religion, today the global human population is estimated by the United Nations to be near 7.5 billion. In common usage, the word generally refers to the only extant species of the genus Homo—anatomically and behaviorally modern Homo sapiens. In scientific terms, the meanings of hominid and hominin have changed during the recent decades with advances in the discovery, there is also a distinction between anatomically modern humans and Archaic Homo sapiens, the earliest fossil members of the species. The English adjective human is a Middle English loanword from Old French humain, ultimately from Latin hūmānus, the words use as a noun dates to the 16th century. The native English term man can refer to the species generally, the species binomial Homo sapiens was coined by Carl Linnaeus in his 18th century work Systema Naturae. The generic name Homo is a learned 18th century derivation from Latin homō man, the species-name sapiens means wise or sapient. Note that the Latin word homo refers to humans of either gender, the genus Homo evolved and diverged from other hominins in Africa, after the human clade split from the chimpanzee lineage of the hominids branch of the primates. The closest living relatives of humans are chimpanzees and gorillas, with the sequencing of both the human and chimpanzee genome, current estimates of similarity between human and chimpanzee DNA sequences range between 95% and 99%. The gibbons and orangutans were the first groups to split from the leading to the humans. The splitting date between human and chimpanzee lineages is placed around 4–8 million years ago during the late Miocene epoch, during this split, chromosome 2 was formed from two other chromosomes, leaving humans with only 23 pairs of chromosomes, compared to 24 for the other apes. There is little evidence for the divergence of the gorilla, chimpanzee. Each of these species has been argued to be an ancestor of later hominins
15.
Blood
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Blood is a body fluid in humans and other animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells. In vertebrates, it is composed of blood cells suspended in blood plasma, plasma, which constitutes 55% of blood fluid, is mostly water, and contains dissipated proteins, glucose, mineral ions, hormones, carbon dioxide, and blood cells themselves. Albumin is the protein in plasma, and it functions to regulate the colloidal osmotic pressure of blood. The blood cells are red blood cells, white blood cells. The most abundant cells in blood are red blood cells. These contain hemoglobin, a protein, which facilitates oxygen transport by reversibly binding to this respiratory gas. In contrast, carbon dioxide is mostly transported extracellularly as bicarbonate ion transported in plasma, vertebrate blood is bright red when its hemoglobin is oxygenated and dark red when it is deoxygenated. Some animals, such as crustaceans and mollusks, use hemocyanin to carry oxygen, insects and some mollusks use a fluid called hemolymph instead of blood, the difference being that hemolymph is not contained in a closed circulatory system. In most insects, this blood does not contain oxygen-carrying molecules such as hemoglobin because their bodies are small enough for their system to suffice for supplying oxygen. Jawed vertebrates have an immune system, based largely on white blood cells. White blood cells help to resist infections and parasites, platelets are important in the clotting of blood. Arthropods, using hemolymph, have hemocytes as part of their immune system, Blood is circulated around the body through blood vessels by the pumping action of the heart. Medical terms related to blood often begin with hemo- or hemato- from the Greek word αἷμα for blood. In terms of anatomy and histology, blood is considered a form of connective tissue, given its origin in the bones. The average adult has a volume of roughly 5 litres. These blood cells consist of erythrocytes, leukocytes, and thrombocytes, by volume, the red blood cells constitute about 45% of whole blood, the plasma about 54. 3%, and white cells about 0. 7%. Whole blood exhibits non-Newtonian fluid dynamics, if all human hemoglobin were free in the plasma rather than being contained in RBCs, the circulatory fluid would be too viscous for the cardiovascular system to function effectively. One microliter of blood contains,4.7 to 6.1 million,4.2 to 5.4 million erythrocytes, Red blood cells contain the bloods hemoglobin, mature red blood cells lack a nucleus and organelles in mammals
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Long bones
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The long bones are those that are longer than they are wide. They are one of five types of bones, long, short, flat, irregular, long bones, especially the femur and tibia, are subjected to most of the load during daily activities and they are crucial for skeletal mobility. They grow primarily by elongation of the diaphysis, with an epiphysis at each end of the growing bone, the ends of epiphyses are covered with hyaline cartilage. The longitudinal growth of bones is a result of endochondral ossification at the epiphyseal plate. Bone growth in length is stimulated by the production of growth hormone, the long bones of the human leg comprise nearly half of adult height. The other primary skeletal component of height are the vertebrae and skull, the outside of the bone consists of a layer of connective tissue called the periosteum. Additionally, the shell of the long bone is compact bone. The outer shell of the bone is made of cortical bone also known as compact bone. This is covered by a membrane of tissue called the periosteum. Beneath the cortical bone layer is a layer of cancellous bone. Inside this is the cavity which has an inner core of bone marrow made up of yellow marrow in the adult. There are two congenital disorders of the long bones, in a disorder known as rachitis fetalis anularis the ends of the long bones are enlarged. Another disorder is known as rachitis fetalis micromelica in which there is a deficiency in the growth of the bones, there is a surgical procedure called distraction osteogenesis which is used to lengthen long bones. Stedmans Online Medical Dictionary, 27th Edition Anatomy of long bone
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Short bone
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Short bones are designated as those bones that are as wide as they are long. Their primary function is to support and stability with little to no movement. They are one of five types of bones, short, long, flat, irregular, examples of these bones include the tarsals in the foot and the carpals in the hand. This article incorporates text in the domain from the 20th edition of Grays Anatomy Stedmans Online Medical Dictionary
18.
Flat bone
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Flat bones are bones whose principal function is either extensive protection or the provision of broad surfaces for muscular attachment. These bones are expanded into broad, flat plates, as in the cranium, the ilium, sternum, the flat bones are, the occipital, parietal, frontal, nasal, lacrimal, vomer, hip bone, sternum, ribs, and scapulae. These bones are composed of two layers of compact bone enclosing between them a variable quantity of cancellous bone, which is the location of red bone marrow. In an adult, most red blood cells are formed in flat bones, ossification is started by the formation of layers of undifferentiated connective tissue that hold the area where the flat bone is to come. On a baby, those spots are known as fontanelles, the fontanelles contain connective tissue stem cells, which form into osteoblasts, which secrete calcium phosphate into a matrix of canals. They form a ring in between the membranes, and begin to expand outwards, as they expand they make a bony matrix. This hardened matrix forms the body of the bone, since flat bones are usually thinner than the long bones, they only have red bone marrow, rather than both red and yellow bone marrow. The bone marrow fills the space in the ring of osteoblasts, after the bone is completely ossified, the osteoblasts retract their calcium phosphate secreting tendrils, leaving tiny canals in the bony matrix, known as canaliculi. These canaliculi provide the nutrients needed for the newly transformed osteoblasts and these cells are responsible for the general maintenance of the bone. A third type of cell found in flat bones is called an osteoclast. There are three reasons that osteoclasts are used, the first is for the reparation of bones after a break. They destroy sections of bone that protrude or make reformation difficult and they are also used to obtain necessary calcium from the bones. When a persons blood calcium is low, the osteoclasts take calcium from the bone and put it into the blood for necessary things such as nerve, the last reason that osteoclasts are used is for growing. As the bone grows, its shape changes, the osteoclasts dissolve the part of the bone that must change. This article incorporates text in the domain from the 20th edition of Grays Anatomy
19.
Irregular bone
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The irregular bones are bones which, from their peculiar form, cannot be grouped as long, short, flat or sesamoid bones. They consist of cancellous tissue enclosed within a layer of compact bone. Irregular bones can also be used for joining all parts of the spinal column together, the spine is the place in the human body where the most irregular bones can be found. There are, in all,33 irregular bones found here, the irregular bones are, the vertebrae, sacrum, coccyx, temporal, sphenoid, ethmoid, zygomatic, maxilla, mandible, palatine, inferior nasal concha, and hyoid. This article incorporates text in the domain from the 20th edition of Grays Anatomy Stedmans Online Medical Dictionary
20.
Sesamoid bone
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In anatomy, a sesamoid bone is a bone embedded within a tendon or a muscle. It is derived from the Latin word sesamum, due to the size of most sesamoids. Often, these form in response to strain. Sesamoids act like pulleys, providing a surface for tendons to slide over. Sesamoid bones can be found on joints throughout the body, including and this is the largest sesamoid bone. In the hand — two sesamoid bones are found in the distal portions of the first metacarpal bone. There is also commonly a sesamoid bone in distal portions of the metacarpal bone. In the wrist - The pisiform of the wrist is a sesamoid bone and it is not present at birth and generally develops in children ages 9–12. In the foot - the first metatarsal bone usually has two sesamoid bones at its connection to the big toe, one is found on the lateral side of the first metatarsal while the other is found on the medial side. In some people, only a single sesamoid is found on the first MTP, in the neck - Although the hyoid bone is free floating, it is not technically a sesamoid bone. All sesamoid bones form directly from the connective tissue found in tendons, by contrast, the hyoid bone forms from a cartilaginous precursor like most other bones in the body. In the ear - the lenticular process of the incus is a sesamoid bone, a common foot ailment in dancers is sesamoiditis. This is a form of tendinitis which results from the surrounding the sesamoid becoming inflamed or irritated. A bi-partite sesamoid bone is when the sesamoids are in 2 separate entities — usually congenital, sesamoid bones have a very limited blood supply. They are very difficult to heal when not treated early and often lead to avascular necrosis, in equine anatomy, the term sesamoid bone usually refers to the two sesamoid bones found at the back of the fetlock or metacarpophalangeal/metatarsophalangeal joints in both hindlimbs and forelimbs. Strictly these should be termed the proximal sesamoid bones whereas the navicular bone should be referred to as the distal sesamoid bone, the patella is also a form of sesamoid bone in the horse. In both the giant panda and the red panda, the radial sesamoid is larger than the bone in counterparts such as bears. It is primarily a bony support for the pad above it, the pandas thumb is often cited as a classical example of exaptation, where a trait evolved for one purpose is commandeered for another
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Axial skeleton
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The axial skeleton is the part of the skeleton that consists of the bones of the head and trunk of a vertebrate. In the human skeleton, it consists of 80 bones and is composed of six parts, the bones, the ossicles of the middle ear, the hyoid bone, the rib cage, sternum. The axial skeleton together with the skeleton form the complete skeleton. Another definition of axial skeleton is the bones including the vertebrae, sacrum, coccyx, ribs, flat bones house the brain and other vital organs. This article mainly deals with the skeletons of humans, however. The human axial skeleton consists of 80 different bones and it is the medial core of the body and connects the pelvis to the body, where the appendix skeleton attaches. As the skeleton grows older the bones get weaker with the exception of the skull, the skull remains strong to protect the brain from injury. The rib cage is composed of 12 pairs of ribs plus the sternum for a total of 25 separate bones, the rib cage functions as protection for the vital organs such as the heart and lungs. The ribs are shaped like crescents, with one end flattened, the rounded ends are attached at joints to the thoracic vertebrae at the back and the flattened ends come together at the sternum, in the front. The upper seven pairs of ribs attach to the sternum with costal cartilage and are known as “true ribs. ”The 8th through 10th ribs have non-costal cartilage which connects them to the ribs above. The last two ribs are called “floating ribs” because they do not attach to the sternum or to other ribs, the first rib is the shortest, broadest, flattest, and most curved. The human skull consists of the cranium and the facial bones, the cranium holds and protects the brain in a large space called the cranial vault. The cranium is formed from eight plate-shaped bones which fit together at meeting points called sutures, in addition there are 14 facial bones which form the lower front part of the skull. Together the 22 bones that compose the skull form additional, smaller spaces besides the cranial vault, such as the cavities for the eyes, the ear, the nose. The most important facial bones include the jaw or mandible, the jaw or maxilla, the zygomatic or cheek bone. Humans are born with separate plates which later fuse to allow flexibility as the passes through the pelvis. During development the eight separate plates of the immature bones fuse together into one single structure known as the Skull, the only bone that remains separate from the rest of the skull is the mandible. At birth the majority of humans have 33 separate vertebrae, however, during normal development several vertebrae fuse together, leaving a total of 24, in most cases
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Vertebral column
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The vertebral column, also known as the backbone or spine, is part of the axial skeleton. The vertebral column houses the spinal canal, a cavity that encloses, there are about 50,000 species of animals that have a vertebral column. The human vertebral column is one of the most-studied examples, the articulating vertebrae are named according to their region of the spine. There are seven cervical vertebrae, twelve thoracic vertebrae and five lumbar vertebrae, the number of vertebrae in a region can vary but overall the number remains the same. The number of those in the region however is only rarely changed. There are ligaments extending the length of the column at the front and the back, the vertebrae in the human vertebral column are divided into different regions, which correspond to the curves of the spinal column. The articulating vertebrae are named according to their region of the spine, vertebrae in these regions are essentially alike, with minor variation. These regions are called the spine, thoracic spine, lumbar spine, sacrum. There are seven cervical vertebrae, twelve thoracic vertebrae and five lumbar vertebrae, the number of vertebrae in a region can vary but overall the number remains the same. The number of those in the region however is only rarely changed. The vertebrae of the cervical, thoracic and lumbar spines are independent bones, the vertebrae of the sacrum and coccyx are usually fused and unable to move independently. Two special vertebrae are the atlas and axis, on which the head rests, a typical vertebra consists of two parts, the vertebral body and the vertebral arch. The vertebral arch is posterior, meaning it faces the back of a person, together, these enclose the vertebral foramen, which contains the spinal cord. Because the spinal cord ends in the spine, and the sacrum and coccyx are fused. Two transverse processes and one process are posterior to the vertebral body. The spinous process comes out the back, one transverse process comes out the left, the spinous processes of the cervical and lumbar regions can be felt through the skin. Above and below each vertebra are joints called facet joints and these restrict the range of movement possible, and are joined by a thin portion of the neural arch called the pars interarticularis. In between each pair of vertebrae are two small holes called intervertebral foramina, the spinal nerves leave the spinal cord through these holes
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Appendicular skeleton
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The appendicular skeleton is the portion of the skeleton of vertebrates consisting of the bones or cartilage that support the appendages. Appendages appeared as fins in fish, and subsequently evolved into the limbs of tetrapods. The appendicular skeleton includes the elements within the limbs, as well as supporting pectoral. The word appendicular is the adjective of the appendage, which itself means a part that is joined to something larger. Of the 206 bones in the skeleton, the appendicular skeleton comprises 126. Functionally it is involved in locomotion of the skeleton and manipulation of objects in the environment. The appendicular skeleton forms during development from cartilage, by the process of endochondral ossification, the appendicular skeleton is divided into six major regions, Pectoral girdles - Left and right clavicle and scapula. Arms and forearms - Left and right humerus, ulna and radius, hands - Left and right carpals, metacarpals, proximal phalanges, intermediate phalanges and distal phalanges. Pelvis - Left and right hip bone, thighs and legs - Left and right femur, patella, tibia and fibula. Feet and ankles - Left and right tarsals, metatarsals, proximal phalanges, intermediate phalanges and it is important to realize that through anatomical variation it is common for the skeleton to have many extra bones. The appendicular skeleton of 126 bones and the skeleton of 80 bones together form the complete skeleton of 206 bones in the human body. Unlike the axial skeleton, the skeleton is unfused. This allows for a greater range of motion. Axial skeleton pectoral girdle pelvic girdle Legs Bones
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Tissue (biology)
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In biology, tissue is a cellular organizational level intermediate between cells and a complete organ. A tissue is an ensemble of similar cells from the origin that together carry out a specific function. Organs are then formed by the grouping together of multiple tissues. The study of tissue is known as histology or, in connection with disease, the classical tools for studying tissues are the paraffin block in which tissue is embedded and then sectioned, the histological stain, and the optical microscope. In the last couple of decades, developments in microscopy, immunofluorescence. With these tools, the appearances of tissues can be examined in health and disease. Animal tissues are grouped into four types, connective, muscle, nervous. Collections of tissues joined in structural units to serve a common function compose organs, while all animals can generally be considered to contain the four tissue types, the manifestation of these tissues can differ depending on the type of organism. For example, the origin of the cells comprising a particular type may differ developmentally for different classifications of animals. By contrast, a true epithelial tissue is present only in a layer of cells held together via occluding junctions called tight junctions. This tissue covers all surfaces that come in contact with the external environment such as the skin, the airways. It serves functions of protection, secretion, and absorption, and is separated from other tissues below by a basal lamina and they are made up of cells separated by non-living material, which is called an extracellular matrix. This matrix can be liquid or rigid, for example, blood contains plasma as its matrix and bones matrix is rigid. Connective tissue gives shape to organs and holds them in place, blood, bone, tendon, ligament, adipose and areolar tissues are examples of connective tissues. One method of classifying tissues is to divide them into three types, fibrous connective tissue, skeletal connective tissue, and fluid connective tissue. Muscle cells form the active contractile tissue of the known as muscle tissue or muscular tissue. Muscle tissue functions to force and cause motion, either locomotion or movement within internal organs. Cells comprising the nervous system and peripheral nervous system are classified as nervous tissue
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Skull
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The skull is a bony structure that forms the head of the skeleton in most vertebrates. It supports the structures of the face and provides a cavity for the brain. The skull is composed of two parts, the cranium and the mandible, in the human these two parts are the neurocranium and the viscerocranium or facial skeleton that includes the mandible as its largest bone. The skull forms the anterior most portion of the skeleton and is a product of cephalisation—housing the brain, and several sensory structures such as the eyes, ears, nose, in the human these sensory structures are part of the facial skeleton. In some animals such as horned ungulates, the skull also has a function by providing the mount for the horns. The English word skull is probably derived from Old Norse skulle, while the Latin word cranium comes from the Greek root κρανίον, the skull is made up of a number of fused flat bones, and contains many foramina and processes, and several cavities or sinuses. For details and the constituent bones, see neurocranium and viscerocranium, the human skull is the bony structure that forms the head in the human skeleton. It supports the structures of the face and forms a cavity for the brain, like the skulls of other vertebrates, it protects the brain from injury. The skull consists of two parts, of different embryological origin—the neurocranium and the facial skeleton, the neurocranium forms the protective cranial cavity that surrounds and houses the brain and brainstem. The facial skeleton is formed by the supporting the face. Except for the mandible, all of the bones of the skull are joined together by sutures—synarthrodial joints formed by bony ossification, sometimes there can be extra bone pieces within the suture known as wormian bones or sutural bones. The human skull is considered to consist of twenty-two bones—eight cranial bones. In the neurocranium these are the bone, two temporal bones, two parietal bones, the sphenoid, ethmoid and frontal bones. The bones of the skeleton are the vomer, two nasal conchae, two nasal bones, two maxilla, the mandible, two palatine bones, two zygomatic bones, and two lacrimal bones. Some of these bones—the occipital, parietal, frontal, in the neurocranium, and the nasal, lacrimal, the skull also contains sinus cavities and numerous foramina. The sinuses are lined with respiratory epithelium and their known functions are the lessening of the weight of the skull, the aiding of resonance to the voice and the warming and moistening of the air drawn through the nasal cavity. The foramina are openings in the skull, the largest of these is the foramen magnum that allows the passage of the spinal cord as well as nerves and blood vessels. The many processes of the include the mastoid process and the zygomatic process
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Rib cage
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The rib cage is an arrangement of bones in the thorax of all vertebrates except the lamprey and the frog. It is formed by the column, ribs, and sternum and encloses the heart. A typical human rib cage consists of 24 ribs, the sternum, costal cartilages, and the 12 thoracic vertebrae. Together with the skin and associated fascia and muscles, the rib cage makes up the wall and provides attachments for the muscles of the neck, thorax, upper abdomen. Ribs are described based on their location and connection with the sternum, ribs that articulate directly with the sternum are called true ribs, whereas those that connect indirectly via cartilage are termed false ribs. The terms true and false rib describe rib pairs that are directly or indirectly attached to the sternum, the phrase true rib, or fixed rib, refers to the first seven, or vertebrosternal, rib pairs. The phrase false rib, or vertebrochondral ribs refers to the pairs of ribs. The eighth-to-tenth pairs of ribs connect to the sternum indirectly via the costal cartilages of the ribs above them and their elasticity allows ribcage movement for respiratory activity. The phrase floating rib refers to the two lowermost, the eleventh and twelfth, rib pairs, so-called because they are attached only to the not to the sternum or cartilage of the sternum. These ribs are small and delicate, and include a cartilaginous tip. The spaces between the ribs are known as intercostal spaces, they contain the intercostal muscles, nerves, arteries, each rib consists of a head, neck, and a shaft and they are numbered from top to bottom. The head of rib is the end part closest to the spine with which it articulates and it is marked by a kidney-shaped articular surface which is divided by a horizontal crest into two facets. The superior facet is smaller and articulates with the vertebra above, the transverse process of a thoracic vertebra also articulates with the rib of the same number. The crest gives attachment to the intra-articular ligament, all ribs are attached posteriorly to the thoracic vertebrae. The neck of the rib is the part that extends laterally from the head. The neck is about 3 cm long, and is placed in front of the process of the lower of the two vertebrae with which the head articulates. Its anterior surface is flat and smooth, whilst its posterior is perforated by numerous foramina and its surface rough and its upper border presents a rough crest for the attachment of the anterior costotransverse ligament, its lower border is rounded. On the posterior surface at the junction of the neck and body, and nearer the lower than the border, is an eminence—the tubercle, it consists of an articular
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Adipose tissue
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In biology, adipose tissue /ˈædᵻˌpoʊs/, body fat, or simply fat is a loose connective tissue composed mostly of adipocytes. Adipose tissue is derived from preadipocytes and its main role is to store energy in the form of lipids, although it also cushions and insulates the body. Far from being hormonally inert, adipose tissue has, in recent years, been recognized as an endocrine organ, as it produces hormones such as leptin, estrogen, resistin. The two types of tissue are white adipose tissue, which stores energy, and brown adipose tissue. The formation of adipose tissue appears to be controlled in part by the adipose gene, Adipose tissue – more specifically brown adipose tissue – was first identified by the Swiss naturalist Conrad Gessner in 1551. In humans, adipose tissue is located beneath the skin, around internal organs, in bone marrow, intermuscular, Adipose tissue is found in specific locations, which are referred to as adipose depots. Apart from adipocytes, which comprise the highest percentage of cells within adipose tissue, other types are present. SVF includes preadipocytes, fibroblasts, adipose tissue macrophages, and endothelial cells, Adipose tissue contains many small blood vessels. In the integumentary system, which includes the skin, it accumulates in the deepest level, around organs, it provides protective padding. Adipose depots in different parts of the body have different biochemical profiles, under normal conditions, it provides feedback for hunger and diet to the brain. Mice have eight major adipose depots, four of which are within the abdominal cavity, the mesenteric depot forms a glue-like web that supports the intestines and the omental depot and - when massive - extends into the ventral abdomen. Both the mesenteric and omental depots incorporate much lymphoid tissue as lymph nodes and milky spots, the layer of brown adipose tissue in this depot is often covered by a frosting of white adipose tissue, sometimes these two types of fat are hard to distinguish. The inguinal depots enclose the inguinal group of lymph nodes, minor depots include the pericardial, which surrounds the heart, and the paired popliteal depots, between the major muscles behind the knees, each containing one large lymph node. Of all the depots in the mouse, the depots are the largest. In an obese person, excess adipose tissue hanging downward from the abdomen is referred to as a panniculus, a panniculus complicates surgery of the morbidly obese individual. It may remain as an apron of skin if a severely obese person quickly loses large amounts of fat. This condition cannot be corrected through diet and exercise alone, as the panniculus consists of adipocytes and other supporting cell types shrunken to their minimum volume. Reconstructive surgery is one method of treatment, visceral fat or abdominal fat is located inside the abdominal cavity, packed between the organs
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Body cavity
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A body cavity is any fluid-filled space in a multicellular organism other than those of vessels. The human body cavity normally refers to the body cavity. A coelom is a cavity lined by a derived from mesoderm. Organs formed inside a coelom can freely move, grow, and develop independently of the wall while fluid cushions. Arthropods and most mollusks have a coelom, usually the pericardial cavity. Their principal body cavity is the hemocoel or haeomocoel of a circulatory system. Mammalian embryos develop two cavities, the coelom and the extraembryonic coelom. The intraembryonic coelom is lined by somatic and splanchnic lateral plate mesoderm, the intraembryonic coelom is the only cavity that persists in the mammal at term, which is why its name is often contracted to simply coelomic cavity. Subdividing the coelomic cavity into compartments, for example, the pericardial cavity / pericardium, organisms can be also classified according to the type of body cavity they possess. Anatomical structures are described in terms of the cavity in which they reside. The body maintains its internal organization by means of membranes, sheaths, the dorsal cavity and the ventral cavity are the largest body compartments. These cavities contain and protect delicate internal organs, and the cavity allows for significant changes in the size. The lungs, heart, stomach, and intestines, for example, can expand, the ventral cavity includes the thoracic and abdominopelvic cavities and their subdivisions. The dorsal cavity includes the cranial and spinal cavities, the cranial cavity is a large, bean-shaped cavity filling most of the upper skull where the brain is located. The vertebral cavity is a narrow, thread-like cavity running from the cranial cavity down the entire length of the spinal cord. Together the cranial cavity and vertebral cavity can be referred to as the body cavity. In the posterior cavity, the cranial cavity houses the brain, just as the brain and spinal cord make up a continuous, uninterrupted structure, the cranial and spinal cavities that house them are also continuous. The thoracic cavity consists of three cavities that fill the area of the chest
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Fat
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Fat is one of the three main macronutrients, along with carbohydrate and protein. Fats, also known as triglycerides, are esters of three fatty acid chains and the alcohol glycerol, the terms oil, fat, and lipid are often confused. Oil normally refers to a fat with short or unsaturated fatty acid chains that is liquid at room temperature, lipid is the general term, as a lipid is not necessarily a triglyceride. Fats, like lipids, are generally hydrophobic, and are soluble in organic solvents. Fat is an important foodstuff for many forms of life, and they are a necessary part of the diet of most heterotrophs. Some fatty acids that are set free by the digestion of fats are called essential because they cannot be synthesized in the body from simpler constituents, there are two essential fatty acids in human nutrition, alpha-linolenic acid and linoleic acid. Other lipids needed by the body can be synthesized from these, fats and other lipids are broken down in the body by enzymes called lipases produced in the pancreas. Fats and oils are categorized according to the number and bonding of the atoms in the aliphatic chain. Fats that are saturated fats have no double bonds between the carbons in the chain, unsaturated fats have one or more double bonded carbons in the chain. The nomenclature is based on the end of the chain. This end is called the end or the n-end. Thus alpha-linolenic acid is called an omega-3 fatty acid because the 3rd carbon from that end is the first double bonded carbon in the counting from that end. Some oils and fats have double bonds and are therefore called polyunsaturated fats. Unsaturated fats can be divided into cis fats, which are the most common in nature, and trans fats. Unsaturated fats can be altered by reaction with hydrogen effected by a catalyst and this action, called hydrogenation, tends to break all the double bonds and makes a fully saturated fat. However, trans fats are generated during hydrogenation as contaminants created by a side reaction on the catalyst during partial hydrogenation. Saturated fats can stack themselves in a closely packed arrangement, so they can easily and are typically solid at room temperature. For example, animal fats tallow and lard are high in saturated fatty acid content and are solids, olive and linseed oils on the other hand are unsaturated and liquid
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Blood cell
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A blood cell, also called a haematopoietic cell, hemocyte, or hematocyte, is a cell produced through hematopoiesis and found mainly in the blood. Red blood cells – Erythrocytes White blood cells – Leukocytes Platelets – Thrombocytes, together, these three kinds of blood cells add up to a total 45% of the blood tissue by volume, with the remaining 55% of the volume composed of plasma, the liquid component of blood. The volume percentage of red cells in the blood is measured by centrifuge or flow cytometry and is 45% of cells to total volume in males. Haemoglobin is an protein that facilitates transportation of oxygen from the lungs to tissues. Red blood cells or erythrocytes, primarily oxygen and collect carbon dioxide through the use of haemoglobin. In the process of being formed they go through a unipotent stem cell stage and they have the job alongside the white blood cells of protecting the healthy cells. RBCs are formed in the red marrow in the adults. After the completion of their lifespan, they are destroyed in the spleen, White blood cells or leukocytes, are cells of the immune system involved in defending the body against both infectious disease and foreign materials. Five diverse types of leukocytes exist, and are all produced and derived from multipotent cells in the bone known as a hematopoietic stem cells. They live for about 3 to 4 days in the human body. Leukocytes are found throughout the body, including the blood and lymphatic system, the two main categories of white blood cells are granulocytes and agranulocytes. Neutrophils are the most abundant of all the WBCs, Platelets, or thrombocytes or yellow blood cells, are very small, irregularly shaped clear cell fragments, 2–3 µm in diameter, which derive from fragmentation of precursor megakaryocytes. The average lifespan of a platelet is normally just 5 to 9 days, Platelets are a natural source of growth factors. They circulate in the blood of mammals and are involved in hemostasis, Platelets release thread-like fibers to form these clots. If the number of platelets is too low, excessive bleeding can occur, an abnormality or disease of the platelets is called a thrombocytopathy, which can be either a low number of platelets, a decrease in function of platelets, or an increase in the number of platelets. Platelets release a multitude of factors including Platelet-derived growth factor, a potent chemotactic agent, and TGF beta. Both of these factors have been shown to play a significant role in the repair. Local application of factors in increased concentrations through Platelet-rich plasma has been used as an adjunct to wound healing for several decades
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Red blood cell
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RBCs take up oxygen in the lungs, or gills of fish, and release it into tissues while squeezing through the bodys capillaries. The cytoplasm of erythrocytes is rich in hemoglobin, a biomolecule that can bind oxygen and is responsible for the red color of the cells. In humans, mature red cells are flexible and oval biconcave disks. They lack a nucleus and most organelles, in order to accommodate maximum space for hemoglobin, they can be viewed as sacks of hemoglobin. Approximately 2.4 million new erythrocytes are produced per second in human adults, the cells develop in the bone marrow and circulate for about 100–120 days in the body before their components are recycled by macrophages. Each circulation takes about 60 seconds, approximately a quarter of the cells in the human body are red blood cells. Nearly half of the volume is red blood cells. Red blood cells are known as RBCs, red cells, red blood corpuscles, haematids. Packed red blood cells are red blood cells that have donated, processed. Almost all vertebrates, including all mammals and humans, have red blood cells, red blood cells are cells present in blood in order to transport oxygen. The only known vertebrates without red blood cells are the crocodile icefish, they live in very cold water. While they no longer use hemoglobin, remnants of hemoglobin genes can be found in their genome, oxygen can easily diffuse through the red blood cells cell membrane. Myoglobin, a related to hemoglobin, acts to store oxygen in muscle cells. The color of red cells is due to the heme group of hemoglobin. However, blood can appear bluish when seen through the vessel wall, pulse oximetry takes advantage of the hemoglobin color change to directly measure the arterial blood oxygen saturation using colorimetric techniques. Hemoglobin also has a high affinity for carbon monoxide, forming carboxyhemoglobin which is a very bright red in color. Flushed, confused patients with a reading of 100% on pulse oximetry are sometimes found to be suffering from carbon monoxide poisoning. The red blood cells of mammals are typically shaped as disks, flattened and depressed in the center, with a dumbbell-shaped cross section
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Platelet
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Platelets, also called thrombocytes, are a component of blood whose function is to stop bleeding by clumping and clotting blood vessel injuries. Platelets have no nucleus, they are fragments of cytoplasm that are derived from the megakaryocytes of the bone marrow. These unactivated platelets are biconvex discoid structures, 2–3 µm in greatest diameter, platelets are found only in mammals, whereas in other animals thrombocytes circulate as intact mononuclear cells. On a stained blood smear, platelets appear as purple spots. The smear is used to examine platelets for size, shape, qualitative number, the ratio of platelets to red blood cells in a healthy adult is 1,10 to 1,20. The main function of platelets is to contribute to hemostasis, the process of stopping bleeding at the site of interrupted endothelium and they gather at the site and unless the interruption is physically too large, they plug the hole. First, platelets attach to substances outside the interrupted endothelium, adhesion, second, they change shape, turn on receptors and secrete chemical messengers, activation. Third, they connect to each other through receptor bridges, aggregation, formation of this platelet plug is associated with activation of the coagulation cascade with resultant fibrin deposition and linking. These processes may overlap, the spectrum is from a predominantly platelet plug, or white clot to a predominantly fibrin clot, the final result is the clot. Some would add the subsequent clot retraction and platelet inhibition as fourth and fifth steps to the completion of the process, low platelet concentration is thrombocytopenia and is due to either decreased production or increased destruction. Elevated platelet concentration is thrombocytosis and is either congenital, reactive, or due to unregulated production, a disorder of platelet function is a thrombocytopathy. An arterial thrombus may partially obstruct blood flow, causing downstream ischemia, or may completely obstruct it, george Gulliver in 1841 drew pictures of platelets using the twin lens microscope invented in 1830 by Joseph Jackson Lister. This microscope improved resolution sufficiently to make it possible to see platelets for the first time, william Addison in 1842 drew pictures of a platelet-fibrin clot. Lionel Beale in 1864 was the first to publish a drawing showing platelets, max Schultze in 1865 described what he called spherules, which he noted were much smaller than red blood cells, occasionally clumped, and were sometimes found in collections of fibrin material. Queens College, Birmingham physician Dr Richard Hill Norris was the first to describe the action of platelets in 1880, giulio Bizzozero in 1882 studied the blood of amphibians microscopically in vivo. He named Schultzs spherules piastrine, little plates, william Osler observed them and, in published lectures in 1886, called them a third corpuscle and a blood plaque and described them as a colorless protoplasmic disc. Thrombocytes are cells found in the blood of non-mammalian vertebrates and they are the functional equivalents of platelets, but circulate as intact mononuclear cells, and are not simply cytoplasmic fragments of bone marrow megakaryocytes. In some contexts, the thrombus is used interchangeably with the word clot
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Leukocyte
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White blood cells, also called leukocytes or leucocytes, are the cells of the immune system that are involved in protecting the body against both infectious disease and foreign invaders. All white blood cells are produced and derived from multipotent cells in the bone known as hematopoietic stem cells. Leukocytes are found throughout the body, including the blood and lymphatic system, all white blood cells have nuclei, which distinguishes them from the other blood cells, the anucleated red blood cells and platelets. Types of white cells can be classified in standard ways. Two pairs of broadest categories classify them either by structure or by cell division lineage and these broadest categories can be further divided into the five main types, neutrophils, eosinophils, basophils, lymphocytes, and monocytes. These types are distinguished by their physical and functional characteristics, further subtypes can be classified, for example, among lymphocytes, there are B cells, T cells, and NK cells. The number of leukocytes in the blood is often an indicator of disease, the normal white cell count is usually between 4 × 109/L and 11 × 109/L. In the US this is expressed as 4,000 to 11,000 white blood cells per microliter of blood. They make up approximately 1% of the blood volume in a healthy adult. However, this 1% of the blood makes a difference to health. An increase in the number of leukocytes over the limits is called leukocytosis. It is normal when it is part of immune responses. It is occasionally abnormal, when it is neoplastic or autoimmune in origin, a decrease below the lower limit is called leukopenia. The name white blood cell derives from the appearance of a blood sample after centrifugation. White cells are found in the buff, a thin, typically white layer of nucleated cells between the red blood cells and the blood plasma. The scientific term leukocyte directly reflects its description and it is derived from the Greek roots leuk- meaning white and cyt- meaning cell. The buffy coat may sometimes be green if there are large amounts of neutrophils in the sample, all white blood cells are nucleated, which distinguishes them from the anucleated red blood cells and platelets. Types of leukocytes can be classified in standard ways, two pairs of broadest categories classify them either by structure or by cell lineage
34.
Mineral balance
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In the context of nutrition, a mineral is a chemical element required as an essential nutrient by organisms to perform functions necessary for life. Minerals originate in the earth and cannot be made by living organisms, most of the minerals in a human diet come from eating plants and animals or from drinking water. As a group, minerals is one of the four groups of essential nutrients, the others of which are vitamins, essential fatty acids, the five major minerals in the human body are calcium, phosphorus, potassium, sodium, and magnesium. All of the elements in a human body are called trace elements. The trace elements that have a specific function in the human body are iron, cobalt, copper, zinc, manganese, molybdenum, iodine. Most chemical elements that are ingested by organisms are in the form of simple compounds, plants absorb dissolved elements in soils, which are subsequently ingested by the herbivores that eat them, and the elements move up the food chain. Larger organisms may also consume soil or use mineral resources, such as salt licks, one element, cobalt, is available for use by animals only after having been processed into complex molecules by bacteria. Minerals are used by animals and microorganisms for the process of mineralizing structures, called biomineralization, used to construct bones, seashells, eggshells, exoskeletons and mollusc shells. At least twenty chemical elements are known to be required to support human biochemical processes by serving structural and functional roles as well as electrolytes, however, as many as twenty-nine elements in total are suggested to be used by mammals, as inferred by biochemical and uptake studies. Phosphorus makes up about 1% of a body weight. The last four major minerals make up only about 0. 85% of the weight of the body, together these eleven chemical elements make up 99. 85% of the body. Minerals are present in a human beings blood at certain mass. The figure below presents the concentrations of each of the elements discussed in this article. Depending on the concentrations, some are in part of the picture. The figure includes the values of other constituents of blood such as hormones. In the figure, minerals are color highlighted in purple, dietitians may recommend that minerals are best supplied by ingesting specific foods rich with the chemical element of interest. The elements may be present in the food or added to the food. The dietary focus on chemical elements derives from an interest in supporting the biochemical reactions of metabolism with the elemental components
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Mineral
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A mineral is a naturally occurring chemical compound, usually of crystalline form and abiogenic in origin. A mineral has one specific chemical composition, whereas a rock can be an aggregate of different minerals or mineraloids, the study of minerals is called mineralogy. There are over 5,300 known mineral species, over 5,070 of these have been approved by the International Mineralogical Association, the silicate minerals compose over 90% of the Earths crust. The diversity and abundance of species is controlled by the Earths chemistry. Silicon and oxygen constitute approximately 75% of the Earths crust, which translates directly into the predominance of silicate minerals, minerals are distinguished by various chemical and physical properties. Differences in chemical composition and crystal structure distinguish the various species, changes in the temperature, pressure, or bulk composition of a rock mass cause changes in its minerals. Minerals can be described by their various properties, which are related to their chemical structure. Common distinguishing characteristics include crystal structure and habit, hardness, lustre, diaphaneity, colour, streak, tenacity, cleavage, fracture, parting, more specific tests for describing minerals include magnetism, taste or smell, radioactivity and reaction to acid. Minerals are classified by key chemical constituents, the two dominant systems are the Dana classification and the Strunz classification, the silicate class of minerals is subdivided into six subclasses by the degree of polymerization in the chemical structure. All silicate minerals have a unit of a 4− silica tetrahedron—that is, a silicon cation coordinated by four oxygen anions. These tetrahedra can be polymerized to give the subclasses, orthosilicates, disilicates, cyclosilicates, inosilicates, phyllosilicates, other important mineral groups include the native elements, sulfides, oxides, halides, carbonates, sulfates, and phosphates. The first criterion means that a mineral has to form by a natural process, stability at room temperature, in the simplest sense, is synonymous to the mineral being solid. More specifically, a compound has to be stable or metastable at 25 °C, modern advances have included extensive study of liquid crystals, which also extensively involve mineralogy. Minerals are chemical compounds, and as such they can be described by fixed or a variable formula, many mineral groups and species are composed of a solid solution, pure substances are not usually found because of contamination or chemical substitution. Finally, the requirement of an ordered atomic arrangement is usually synonymous with crystallinity, however, crystals are also periodic, an ordered atomic arrangement gives rise to a variety of macroscopic physical properties, such as crystal form, hardness, and cleavage. There have been recent proposals to amend the definition to consider biogenic or amorphous substances as minerals. The formal definition of an approved by the IMA in 1995, A mineral is an element or chemical compound that is normally crystalline. However, if geological processes were involved in the genesis of the compound, Mineral classification schemes and their definitions are evolving to match recent advances in mineral science
36.
Cardiac muscle
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Cardiac muscle is an involuntary, striated muscle that is found in the walls and histological foundation of the heart, specifically the myocardium. Cardiac muscle is one of three types of muscle, the others being skeletal and smooth muscle. These three types of all form in the process of myogenesis. The cells that constitute cardiac muscle, called cardiomyocytes or myocardiocytes, predominantly contain only one nucleus, the myocardium is the muscle tissue of the heart, and forms a thick middle layer between the outer epicardium layer and the inner endocardium layer. Coordinated contractions of cardiac cells in the heart pump blood out of the atria and ventricles to the blood vessels of the left/body/systemic. This complex mechanism illustrates systole of the heart, Cardiac muscle cells, unlike most other tissues in the body, rely on an available blood and electrical supply to deliver oxygen and nutrients and remove waste products such as carbon dioxide. The coronary arteries help fulfill this function, Cardiac muscle has cross striations formed by rotating segments of thick and thin protein filaments. Like skeletal muscle, the structural proteins of cardiac muscle are myosin and actin. However, in contrast to skeletal muscle, cardiac muscle cells are typically branch-like instead of linear, another histological difference between cardiac muscle and skeletal muscle is that the T-tubules in the cardiac muscle are bigger and wider and track laterally to the Z-discs. There are fewer T-tubules in comparison with skeletal muscle, the diad is a structure in the cardiac myocyte located at the sarcomere Z-line. It is composed of a single T-tubule paired with a terminal cisterna of the sarcoplasmic reticulum, the diad plays an important role in excitation-contraction coupling by juxtaposing an inlet for the action potential near a source of Ca2+ ions. This way, the wave of depolarization can be coupled to calcium-mediated cardiac muscle contraction via the sliding filament mechanism, Cardiac muscle forms these instead of the triads formed between the sarcoplasmic reticulum in skeletal muscle and T-tubules. T-tubules play critical role in excitation-contraction coupling, recently, the action potentials of T-tubules were recorded optically by Guixue Bu et al. There is a syncytium and a ventricular syncytium that are connected by cardiac connection fibres. Electrical resistance through intercalated discs is very low, thus allowing free diffusion of ions, the ease of ion movement along cardiac muscle fibers axes is such that action potentials are able to travel from one cardiac muscle cell to the next, facing only slight resistance. Each syncytium obeys the all or none law, intercalated discs are complex adhering structures that connect the single cardiomyocytes to an electrochemical syncytium. The discs are responsible mainly for force transmission during muscle contraction, intercalated discs consist of three different types of cell-cell junctions, the actin filament anchoring adherens junctions, the intermediate filament anchoring desmosomes, and gap junctions. They allow action potentials to spread between cells by permitting the passage of ions between cells, producing depolarization of the heart muscle
. PMID 18259783.