1.
Disease
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A disease is a particular abnormal condition, a disorder of a structure or function, that affects part or all of an organism. The study of disease is called pathology which includes the study of cause, Disease is often construed as a medical condition associated with specific symptoms and signs. When caused by pathogens, even in the literature, the term disease is often misleadingly used in the place of its causal agent. This language habitat can cause confusion in the communication of the principle in epidemiology. Diseases can affect not only physically, but also emotionally. Death due to disease is called death by natural causes, there are four main types of disease, infectious diseases, deficiency diseases, genetic diseases, and physiological diseases. Diseases can also be classified as communicable and non-communicable, the deadliest diseases in humans are coronary artery disease, followed by cerebrovascular disease and lower respiratory infections. In many cases, terms such as disease, disorder, morbidity, there are situations, however, when specific terms are considered preferable. Disease The term disease broadly refers to any condition that impairs the normal functioning of the body, for this reason, diseases are associated with dysfunctioning of the bodys normal homeostatic processes. The term disease has both a count sense and a noncount sense, by contrast, an infection that is asymptomatic during its incubation period, but expected to produce symptoms later, is usually considered a disease. Non-infectious diseases are all other diseases, including most forms of cancer, heart disease, acquired disease disease that began at some point during ones lifetime, as opposed to disease that was already present at birth, which is congenital disease. Acquired sounds like it could mean caught via contagion, but it simply means acquired sometime after birth and it also sounds like it could imply secondary disease, but acquired disease can be primary disease. It is often, genetic and can be inherited and it can also be the result of a vertically transmitted infection from the mother such as HIV/AIDS. Genetic disease disease that is caused by genetic mutation and it is often inherited, but some mutations are random and de novo. Hereditary or inherited disease a type of disease caused by mutation that is hereditary Iatrogenic disease A disease condition caused by medical intervention. Idiopathic disease disease whose cause is unknown, as medical science has advanced, many diseases whose causes were formerly complete mysteries have been somewhat explained or even extensively explained. Bacterial infections can be primary or secondary to a viral infection or burn. Terminal disease disease with death as an inevitable result Illness Illness is generally used as a synonym for disease, however, this term is occasionally used to refer specifically to the patients personal experience of his or her disease
2.
Lymph node
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A lymph node or lymph gland, is an ovoid or kidney-shaped organ of the lymphatic system, and of the adaptive immune system, that is widely present throughout the body. They are linked by the vessels as a part of the circulatory system. Lymph nodes are major sites of B and T lymphocytes, Lymph nodes are important for the proper functioning of the immune system, acting as filters for foreign particles and cancer cells. Lymph nodes do not have a function, which is primarily dealt with by the liver. In the lymphatic system the lymph node is a secondary lymphoid organ, a lymph node is enclosed in a fibrous capsule and is made up of an outer cortex and an inner medulla. Lymph nodes also have clinical significance and they become inflamed or enlarged in various diseases which may range from trivial throat infections, to life-threatening cancers. The condition of the nodes is very important in cancer staging, which decides the treatment to be used. When swollen, inflamed or enlarged, lymph nodes can be hard, Lymph nodes are kidney or oval shaped and range in size from a few millimeters to about 1–2 cm long. Each lymph node is surrounded by a capsule, which extends inside the lymph node to form trabeculae. The substance of the node is divided into the outer cortex. The cortex is continuous around the medulla except where the medulla comes into contact with the hilum. Thin reticular fibers of reticular connective tissue, and elastin form a supporting meshwork called a reticulin inside the node, B cells, are mainly found in the outer where they are clustered together as follicular B cells in lymphoid follicles and the T cells are mainly in the paracortex. The number and composition of follicles can change especially when challenged by an antigen, elsewhere in the node, there are only occasional leucocytes. As part of the network there are follicular dendritic cells in the B cell follicle. The reticular network not only provides the support, but also the surface for adhesion of the dendritic cells. It allows exchange of material with blood through the high endothelial venules and provides the growth and regulatory factors necessary for activation and maturation of immune cells. All of these sinuses drain the filtered lymphatic fluid into the medullary sinuses and these vessels are smaller and dont allow the passage of the macrophages so that they remain contained to function within the lymph node. In the course of the lymph, lymphocytes may be activated as part of the immune response
3.
Inflammation
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The classical signs of inflammation are heat, pain, redness, swelling, and loss of function. Inflammation is a response, and therefore it is considered as a mechanism of innate immunity, as compared to adaptive immunity. Too little inflammation could lead to tissue destruction by the harmful stimulus. In contrast, chronic inflammation may lead to a host of diseases, such as hay fever, periodontitis, atherosclerosis, rheumatoid arthritis, Inflammation is therefore normally closely regulated by the body. Inflammation can be classified as acute or chronic. Acute inflammation is the response of the body to harmful stimuli and is achieved by the increased movement of plasma. A series of biochemical events propagates and matures the inflammatory response, involving the vascular system, the immune system. Inflammation is not a synonym for infection, Inflammation on the other hand describes purely the bodys immunovascular response, whatever the cause may be. But because of how often the two are correlated, words ending in the suffix -itis are sometimes described as referring to infection. There are also situations where microbial invasion does not result in classic inflammatory response—for example, parasitosis. Acute inflammation is a process, usually appearing within a few minutes or hours. It involves a coordinated and systemic mobilisation response locally of various immune, endocrine, in a normal healthy response, it becomes activated, clears the pathogen and begins a repair process and then ceases. It is characterized by five signs, An acronym that may be used to remember the key symptoms is PRISH, for pain, redness, immobility, swelling. Loss of function has multiple causes, Acute inflammation of the lung does not cause pain unless the inflammation involves the parietal pleura, which does have pain-sensitive nerve endings. PAMPs are compounds that are associated with pathogens, but which are distinguishable from host molecules. DAMPs are compounds that are associated with host-related injury and cell damage, at the onset of an infection, burn, or other injuries, these cells undergo activation and release inflammatory mediators responsible for the clinical signs of inflammation. Vasodilation and its resulting increased blood flow causes the redness and increased heat, increased permeability of the blood vessels results in an exudation of plasma proteins and fluid into the tissue, which manifests itself as swelling. Some of the released mediators such as increase the sensitivity to pain
4.
Synonym
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A synonym is a word or phrase that means exactly or nearly the same as another word or phrase in the same language. Words that are synonyms are said to be synonymous, and the state of being a synonym is called synonymy, the word comes from Ancient Greek sýn and ónoma. An example of synonyms are the words begin, start, commence, words can be synonymous when meant in certain senses, even if they are not synonymous in all of their senses. For example, if one talks about a time or an extended time, long. Some academics call the former type cognitive synonyms to distinguish them from the latter type, some lexicographers claim that no synonyms have exactly the same meaning because etymology, orthography, phonic qualities, ambiguous meanings, usage, etc. make them unique. Different words that are similar in meaning usually differ for a reason, feline is more formal than cat, long and extended are only synonyms in one usage, synonyms are also a source of euphemisms. In the figurative sense, two words are said to be synonymous if they have the same connotation. a widespread impression that. Metonymy can sometimes be a form of synonymy, as when, for example, thus a metonym is a type of synonym, and the word metonym is a hyponym of the word synonym. The analysis of synonymy, polysemy, hyponymy, and hypernymy is inherent to taxonomy and it has applications in pedagogy and machine learning, because they rely on word-sense disambiguation and schema. Synonyms can be any part of speech, as long as both words belong to the part of speech. Such like, he expired means the same as he died, in English, many synonyms emerged in the Middle Ages, after the Norman conquest of England. While Englands new ruling class spoke Norman French, the lower classes continued to speak Old English, thus, today we have synonyms like the Norman-derived people, liberty and archer, and the Saxon-derived folk, freedom and bowman. For more examples, see the list of Germanic and Latinate equivalents in English, the purpose of a thesaurus is to offer the user a listing of similar or related words, these are often, but not always, synonyms. The word poecilonym is a synonym of the word synonym. It is not entered in most major dictionaries and is a curiosity or piece of trivia for being a word because of its meta quality as a synonym of synonym. Antonyms are words with opposite or nearly opposite meanings, for example, hot ↔ cold, large ↔ small, thick ↔ thin, synonym ↔ antonym Hypernyms and hyponyms are words that refer to, respectively, a general category and a specific instance of that category. For example, vehicle is a hypernym of car, and car is a hyponym of vehicle, homophones are words that have the same pronunciation, but different meanings. For example, witch and which are homophones in most accents, homographs are words that have the same spelling, but have different pronunciations
5.
Lymphatic vessel
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In anatomy, lymphatic vessels are thin-walled, valved structures that carry lymph. As part of the system, lymph vessels are complementary to the cardiovascular system. Lymph vessels are lined by endothelial cells, and have a layer of smooth muscles. Lymph vessels are devoted to propulsion of the lymph from the lymph capillaries, lymph capillaries are slightly larger than their counterpart capillaries of the vascular system. Lymph ducts drain the lymph into one of the subclavian veins, generally, lymph flows away from the tissues to lymph nodes and eventually to either the right lymphatic duct or the largest lymph vessel in the body, the thoracic duct. These vessels drain into the right and left subclavian veins respectively, the general structure of lymphatics is based on that of blood vessels. There is a lining of single flattened epithelial cells composed of a type of epithelium that is called endothelium. This layer functions to mechanically transport fluid and since the basement membrane on which it rests is discontinuous, the next layer is that of smooth muscles that are arranged in a circular fashion around the endothelium, which by shortening or relaxing alter the diameter of the lumen. The outermost layer is the adventitia that consists of fibrous tissue, the general structure described here is seen only in larger lymphatics, smaller lymphatics have fewer layers. The smallest vessels lack both the muscular layer and the outer adventitia, as they proceed forward and in their course are joined by other capillaries, they grow larger and first take on an adventitia, and then smooth muscles. Unlike the cardiovascular system, the system is not closed and has no central pump. Lymph movement occurs despite low pressure due to peristalsis, valves and these button-like junctions consist of protein filaments like platelet endothelial cell adhesion molecule-1, or PECAM-1. A valve system in place here prevents the absorbed lymph from leaking back into the ISF, there is another system of semilunar valves that prevents back-flow of lymph along the lumen of the vessel. Lymph capillaries have many interconnections between them and form a fine network. Rhythmic contraction of the walls through movements may also help draw fluid into the smallest lymphatic vessels. If tissue fluid builds up the tissue will swell, this is called edema, the system collaborates with white blood cells in lymph nodes to protect the body from being infected by cancer cells, fungi, viruses or bacteria. This is known as a circulatory system. The lymph capillaries drain the lymph to larger contractile lymphatics, which have valves as well as smooth muscle walls and these are called the collecting lymphatics
6.
Lymph
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Lymph is the fluid that circulates throughout the lymphatic system. The lymph is formed when the fluid is collected through lymph capillaries. Since the lymph is derived from the fluid, its composition continually changes as the blood. It is generally similar to blood plasma except that it doesnt contain red blood cells, lymph returns proteins and excess interstitial fluid to the bloodstream. Lymph may pick up bacteria and bring them to lymph nodes, metastatic cancer cells can also be transported via lymph. Lymph also transports fats from the system to the blood via chylomicrons. The word lymph is derived from the name of the ancient Roman deity of fresh water, lymph has a composition comparable to that of blood plasma, but it may differ slightly. In particular, the lymph that leaves a lymph node is richer in lymphocytes, likewise, the lymph formed in the human digestive system called chyle is rich in triglycerides, and looks milky white because of its lipid content. As the blood and the surrounding cells continually add and remove substances from the interstitial fluid, thus, lymph when formed is a watery clear liquid with the same composition as the interstitial fluid. However, as it flows through the nodes it comes in contact with blood. Tubular vessels transport lymph back to the blood, ultimately replacing the volume lost during the formation of the interstitial fluid and these channels are the lymphatic channels, or simply lymphatics. Unlike the cardiovascular system, the system is not closed and has no central pump. Lymph transport, therefore, is slow and sporadic, despite low pressure, lymph movement occurs due to peristalsis, valves, and compression during contraction of adjacent skeletal muscle and arterial pulsation. Lymph that enters the lymph vessels from the interstitial spaces usually does not flow backwards along the vessels because of the presence of valves. If excessive hydrostatic pressure develops within the vessels, though, some fluid can leak back into the interstitial spaces. Flow of the lymph in the duct in an average resting person usually approximates 100ml per hour. Accompanied by another ~25ml per hour in other vessels, total lymph flow in the body is about 4 to 5 liters per day. Which can be elevated several folds in case of exercising, thus it can be estimated that without lymphatic flow, an average resting person would die within 24 hours
7.
Micrograph
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A micrograph or photomicrograph is a photograph or digital image taken through a microscope or similar device to show a magnified image of an item. This is opposed to an image, which is at a scale that is visible to the naked eye. Micrography is the practice or art of using microscopes to make photographs, a micrograph contains extensive details that form the features of a microstructure. The neuropathologist Solomon C. Fuller designed and created the first photomicrograph in 1900, micrographs are widely used in all fields of microscopy. A light micrograph or photomicrograph is a micrograph prepared using an optical microscope, at a basic level, photomicroscopy may be performed simply by hooking up a regular camera to a microscope, thereby enabling the user to take photographs at reasonably high magnification. Roman Vishniac was a pioneer in the field of photomicroscopy, specializing in the photography of living creatures in full motion and he also made major developments in light-interruption photography and color photomicroscopy. An electron micrograph is a micrograph prepared using an electron microscope, however, the term electron micrograph is not used in electron microscopy. Digital micrography is a digital picture obtained either directly with a microscope or by scanning of a photomicrograph, digital micrographs are now commonly obtained using a USB microscope attached directly to a home computer or laptop. Today, an add-on three-in-one macro lens which has capability to take wide-angle, fish-eye and macro with 7x, 14x, micrographs usually have micron bars, or magnification ratios, or both. Magnification is a ratio between size of object on a picture and its real size, unfortunately, magnification is somewhat a misleading parameter. It depends on a size of a printed picture. Editors of journals and magazines routinely resize a figure to fit the page, a scale bar, or micron bar, is a bar of known length displayed on a picture. The bar can be used for measurements on a picture, when a picture is resized a bar is also resized. If a picture has a bar, the magnification can be easily calculated, ideally, all pictures destined for publication/presentation should be supplied with a scale bar, the magnification ratio is optional. All but one of the micrographs presented on this page do not have a bar, supplied magnification ratios are likely incorrect. The microscope has been used for scientific discovery. It has also linked to the arts since its invention in the 17th century. At first scientists used the microscope to view and draw objects not visible with the unaided eye, early adopters of the microscope, such as Robert Hooke and Antonie van Leeuwenhoek, were excellent illustrators
8.
H&E stain
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Hematoxylin and eosin stain or haematoxylin and eosin stain is one of the principal stains in histology. A combination of hematoxylin and eosin, it produces blues, violets, the staining method involves application of hemalum, a complex formed from aluminum ions and hematein. Hemalum colors nuclei of cells blue, the nuclear staining is followed by counterstaining with an aqueous or alcoholic solution of eosin Y, which colors eosinophilic structures in various shades of red, pink and orange. The staining of nuclei by hemalum is ordinarily due to binding of the complex to DNA. The mechanism is different from that of nuclear staining by basic dyes such as thionine or toluidine blue, staining by basic dyes occurs only from solutions that are less acidic than hemalum, and it is prevented by prior chemical or enzymatic extraction of nucleic acids. The eosinophilic structures are composed of intracellular or extracellular protein. The Lewy bodies and Mallory bodies are examples of eosinophilic structures, most of the cytoplasm is eosinophilic. Red blood cells are stained intensely red, the structures do not have to be acidic or basic to be called basophilic and eosinophilic, the terminology is based on the affinity of cellular components for the dyes. Other colors, e. g. yellow and brown, can be present in the sample, they are caused by intrinsic pigments, some structures do not stain well. Basal laminae need to be stained by PAS stain or some silver stains, reticular fibers also require silver stain. Hydrophobic structures also tend to clear, these are usually rich in fats, e. g. adipocytes, myelin around neuron axons. Hematoxylin is a blue or violet stain that is basic/positive. DNA/RNA in the nucleus, and RNA in ribosomes in the endoplasmic reticulum are both acidic because the phosphate backbones of nucleic acids are negatively charged. The negatively charged backbones form salts with basic dyes containing positive charges, therefore, dyes like hematoxylin will bind to DNA and RNA and stain them violet. Eosin is a red or pink stain that is Acidic / Negative and it binds to acidophilic substances such as positively charged amino acid side chains. Most proteins in the cytoplasm of cells are basic because they are positively charged due to the arginine and lysine amino acid residues. These form salts with acid dyes containing negative charges, like eosin, therefore, eosin binds to these amino acids/proteins and stains them pink. This includes cytoplasmic filaments in muscle cells, intracellular membranes, kiernan JA Histological and Histochemical Methods, Theory and Practice
9.
Pelvis
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The pelvis is either the lower part of the trunk of the human body between the abdomen and the thighs or the skeleton embedded in it. The pelvic region of the trunk includes the pelvis, the pelvic cavity, the pelvic floor, below the pelvic cavity. The pelvic skeleton is formed in the area of the back, by the sacrum, the two hip bones connect the spine with the lower limbs. They are attached to the sacrum posteriorly, connected to each other anteriorly, in mammals, the bony pelvis has a gap in the middle, significantly larger in females than in males. Their young pass through this gap when they are born, the pelvic region of the trunk is the lower part of the trunk, between the abdomen and the thighs. Each hip bone consists of 3 sections, ilium, ischium, during childhood, these sections are separate bones, joined by the triradiate cartilage. During puberty, they fuse together to form a single bone, the pelvic cavity is a body cavity that is bounded by the bones of the pelvis and which primarily contains reproductive organs and the rectum. A distinction is made between the lesser or true pelvis inferior to the line, and the greater or false pelvis above it. The pelvic outlet or inferior pelvic aperture is the region between the angle or pubic arch, the ischial tuberosities and the coccyx. To achieve both these tasks, the floor is composed of several overlapping sheets of muscles and connective tissues. The pelvic diaphragm is composed of the levator ani and the coccygeus muscle and these arise between the symphysis and the ischial spine and converge on the coccyx and the anococcygeal ligament which spans between the tip of the coccyx and the anal hiatus. This leaves a slit for the anal and urogenital openings, because of the width of the genital aperture, which is wider in females, a second closing mechanism is required. The urogenital diaphragm consists mainly of the deep transverse perineal which arises from the inferior ischial and pubic rami, the urogenital diaphragm is reinforced posteriorly by the superficial transverse perineal. The external anal and urethral sphincters close the anus and the urethra, the former is surrounded by the bulbospongiosus which narrows the vaginal introitus in females and surrounds the corpus spongiosum in males. Ischiocavernosus squeezes blood into the corpus cavernosum penis and clitoridis, modern humans are to a large extent characterized by bipedal locomotion and large brains. The female pelvis, or gynecoid pelvis, has evolved to its width for childbirth — a wider pelvis would make women unable to walk. In contrast, human male pelvises are not constrained by the need to give birth, the principal differences between male and female true and false pelvis include, The female pelvis is larger and broader than the male pelvis which is taller, narrower, and more compact. The female inlet is larger and oval in shape, while the male sacral promontory projects further, the sides of the male pelvis converge from the inlet to the outlet, whereas the sides of the female pelvis are wider apart
10.
Neck
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The neck is the part of the body, on many vertebrates, that separates the head from the torso or trunk. It contains blood vessels and nerves that supply structures in the head to the body. These in humans include part of the esophagus, the larynx, trachea, and thyroid gland, major blood vessels including the arteries and jugular veins. In anatomy, the neck is called by its Latin names, cervix or collum, although when used alone, in context, the word cervix more often refers to the uterine cervix. Thus the adjective cervical may refer either to the neck or to the uterine cervix, the neck contains vessels that links structures in the head to the body. In humans these structures include part of the esophagus, larynx, trachea, thyroid and parathyroid glands, lymph nodes, major blood vessels present include the carotid arteries and the jugular veins. Cervical lymph nodes surround the blood vessels, the thyroid gland and parathyroid gland are endocrine glands involved in the regulation of cellular metabolism and growth, and blood calcium levels. The shape of the neck in humans is formed from the part of the vertebral column at the back. Around these sit soft tissues, including muscles, and between and around these sit the other structures mentioned above, muscles of the neck attach to the base of the skull, the hyoid bone, the clavicles and the sternum. The large platysma, sternocleidomastoid muscles contribute to the shape at the front, a number of other muscles attach to and stem from the hyoid bone, facilitating speech and playing a role in swallowing. Sensation to the front areas of the neck comes from the roots of nerves C2-4, the cervical region of the human spine is made up of seven cervical vertebrae referred to as C-1 to C-7, with cartilaginous discs between each vertebral body. The spinal cord sits within the part of the vertebral column. The spinal column carries nerves that carry sensory and motor information from the brain down to the rest of the body, from top to bottom the cervical spine is gently curved in convex-forward fashion. In addition to coming from and within the human spine. In the middle line below the chin can be felt the body of the bone, just below which is the prominence of the thyroid cartilage called Adams apple. Still lower the cricoid cartilage is easily felt, while between this and the notch the trachea and isthmus of the thyroid gland may be made out. At the side the outline of the muscle is the most striking mark. The upper part of the former contains the submaxillary gland also known as the submandibular glands, the line of the common and the external carotid arteries may be marked by joining the sterno-clavicular articulation to the angle of the jaw
11.
Mediastinum
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The mediastinum is the central compartment of the thoracic cavity surrounded by loose connective tissue, as an undelineated region that contains a group of structures within the thorax. The mediastinum contains the heart and its vessels, the esophagus, trachea, phrenic and cardiac nerves, the mediastinum lies within the thorax and is enclosed on the right and left by pleurae. It is surrounded by the chest wall in front, the lungs to the sides and it extends from the sternum in front to the vertebral column behind, and contains all the organs of the thorax except the lungs. It is continuous with the connective tissue of the neck. The mediastinum can be divided into an upper and lower part, The superior mediastinum starts at the superior thoracic aperture, the thoracic plane separates the superior and inferior mediastinum. It is a plane at the level of the angle. The inferior mediastinum from this level to the diaphragm, anatomists, surgeons, and clinical radiologists compartmentalize the mediastinum differently. For instance, in the scheme of Felson, there are only three compartments, and the heart is part of the anterior mediastinum. The thoracic plane separates the superior and inferior mediastinum and it is a plane at the level of the sternal angle, and the intervertebral disc of T4–T5. Superior and inferior sternopericardial ligaments Middle mediastinum Bounded, pericardial sac – It contains the vital organs and is classified into the serous and fibrous pericardium. The mediastinum is frequently the site of involvement of various tumors, Anterior mediastinum, substernal thyroid goiters, lymphoma, thymoma, Middle mediastinum, lymphadenopathy, metastatic disease such as from small cell carcinoma from the lung. Posterior mediastinum, Neurogenic tumors, either from the sheath or elsewhere. Mediastinitis is inflammation of the tissues in the mediastinum, usually bacterial, as the infection can progress very quickly, this is a serious condition. Pneumomediastinum is the presence of air in the mediastinum, which in some cases can lead to pneumothorax, pneumoperitoneum, however, that does not always occur and sometimes those conditions are actually the cause, not the result, of pneumomediastinum. These conditions frequently accompany Boerhaaves syndrome, or spontaneous esophageal rupture, there are many diseases that can present with a widened mediastinum. The most common ones are aortic unfolding, traumatic aortic rupture, thoracic aortic aneurysm, a widened mediastinum is a classic but rare hallmark sign of anthrax infection. Anatomy figure,21, 02-03 at Human Anatomy Online, SUNY Downstate Medical Center – The anatomical divisions of the inferior mediastinum, thoraxlesson3 at The Anatomy Lesson by Wesley Norman – Subdivisions of the Thoracic Cavity
12.
Axillary lymph nodes
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They are divided in several groups according to their location in the armpit. These lymph nodes are clinically significant in breast cancer, and metastases from the breast to the lymph nodes are considered in the staging of the disease. Posterior group, Lying in front of the muscle, these nodes receive superficial lymph vessels from the back. Lateral group, Lying along the side of the axillary vein. Central group, Lying in the center of the axilla in the axillary fat, infraclavicular group, These nodes are not strictly axillary nodes because they are located outside the axilla. They lie in the groove between the deltoid and pectoralis major muscles and receive superficial lymph vessels from the side of the hand, forearm. Apical group, Lying at the apex of the axilla at the border of the 1st rib. The apical nodes drain into the subclavian lymph trunk, on the left side, this trunk drains into the thoracic duct, on the right side, it drains into the right lymphatic duct. Alternatively, the trunks may drain directly into one of the large veins at the root of the neck. About 75% of lymph from the drains into the axillary lymph nodes. A doctor will usually refer a patient to a surgeon to have an axillary lymph node dissection to see if the cells have been trapped in the nodes. For clinical stages I and II breast cancer, axillary lymph node dissection should only be performed after first attempting sentinel node biopsy, if cancer cells are found in the nodes it increases the risk of metastatic breast cancer. Another method of determining breast cancer spread is to perform an endoscopic axillary sentinel node biopsy and this involves injecting a dye into the breast lump and seeing which node it first spread to. This node is removed and examined. If there is no cancer present, it is assumed the cancer has not spread to the lymph nodes. This procedure is less invasive and less damaging than the axillary lymph node dissection. The estimated risk of lymphedema following sentinel lymph node procedure is less than 3%, axillary lymph nodes are included within the standard tangential fields in radiotherapy for breast cancer. In the case of comprehensive nodal irradiation, which includes axillary levels I, II, the risk is estimated to be less than 5% as the brachial plexus radiation tolerance according to is 60 Gy in standard fractionation
13.
Retroperitoneal space
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The retroperitoneal space is the anatomical space in the abdominal cavity behind the peritoneum. It has no specific delineating anatomical structures, organs are retroperitoneal if they have peritoneum on their anterior side only. Structures that are not suspended by mesentery in the abdominal cavity and it contains the following structures, Adrenal gland Kidney Renal vessels Anterior pararenal space Bounded by the posterior layer of peritoneum and the anterior leaf of the renal fascia. Bleeding from a vessel or structure in the retroperitoneal such as the aorta or inferior vena cava into the retroperitoneal space can lead to a retroperitoneal hemorrhage. Retroperitoneal fibrosis Retroperitoneal lymph node dissection Intraperitoneal
14.
Aorta
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The aorta is the main artery in the human body, originating from the left ventricle of the heart and extending down to the abdomen, where it splits into two smaller arteries. The aorta distributes oxygenated blood to all parts of the body through the systemic circulation, in anatomical sources, the aorta is usually divided into sections. One way of classifying a part of the aorta is by anatomical compartment, the aorta then continues downward as the abdominal aorta diaphragm to the aortic bifurcation. Another system divides the aorta with respect to its course and the direction of blood flow, in this system, the aorta starts as the ascending aorta then travels superiorly from the heart and then makes a hairpin turn known as the aortic arch. Following the aortic arch, the aorta then travels inferiorly as the descending aorta, the descending aorta has two parts. The aorta begins to descend in the cavity, and consequently is known as the thoracic aorta. After the aorta passes through the diaphragm, it is known as the abdominal aorta, the aorta ends by dividing into two major blood vessels, the common iliac arteries and a smaller midline vessel, the median sacral artery. The ascending aorta begins at the opening of the valve in the left ventricle of the heart. It runs through a common pericardial sheath with the pulmonary trunk and these two blood vessels twist around each other, causing the aorta to start out posterior to the pulmonary trunk, but end by twisting to its right and anterior side. The transition from ascending aorta to aortic arch is at the reflection on the aorta. At the root of the aorta, the lumen has three small pockets between the cusps of the aortic valve and the wall of the aorta, which are called the aortic sinuses or the sinuses of Valsalva. The left aortic sinus contains the origin of the coronary artery. Together, these two arteries supply the heart, the posterior aortic sinus does not give rise to a coronary artery. For this reason the left, right and posterior aortic sinuses are also called left-coronary, right-coronary and non-coronary sinuses, in addition to these blood vessels, the aortic arch crosses the left main bronchus. Between the aortic arch and the trunk is a network of autonomic nerve fibers. The left vagus nerve, which passes anterior to the arch, gives off a major branch, the recurrent laryngeal nerve. It then runs back to the neck, the aortic arch has three major branches, from proximal to distal, they are the brachiocephalic trunk, the left common carotid artery, and the left subclavian artery. The brachiocephalic trunk supplies the right side of the head and neck as well as the arm and chest wall
15.
Bacteria
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Bacteria constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a number of shapes, ranging from spheres to rods, Bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit soil, water, acidic hot springs, radioactive waste, Bacteria also live in symbiotic and parasitic relationships with plants and animals. Most bacteria have not been characterised, and only half of the bacterial phyla have species that can be grown in the laboratory. The study of bacteria is known as bacteriology, a branch of microbiology, There are typically 40 million bacterial cells in a gram of soil and a million bacterial cells in a millilitre of fresh water. There are approximately 5×1030 bacteria on Earth, forming a biomass which exceeds that of all plants, Bacteria are vital in many stages of the nutrient cycle by recycling nutrients such as the fixation of nitrogen from the atmosphere. The nutrient cycle includes the decomposition of bodies and bacteria are responsible for the putrefaction stage in this process. In March 2013, data reported by researchers in October 2012, was published and it was suggested that bacteria thrive in the Mariana Trench, which with a depth of up to 11 kilometres is the deepest known part of the oceans. Other researchers reported related studies that microbes thrive inside rocks up to 580 metres below the sea floor under 2.6 kilometres of ocean off the coast of the northwestern United States. According to one of the researchers, You can find microbes everywhere—theyre extremely adaptable to conditions, the vast majority of the bacteria in the body are rendered harmless by the protective effects of the immune system, though many are beneficial particularly in the gut flora. However several species of bacteria are pathogenic and cause diseases, including cholera, syphilis, anthrax, leprosy. The most common fatal diseases are respiratory infections, with tuberculosis alone killing about 2 million people per year. In developed countries, antibiotics are used to treat infections and are also used in farming, making antibiotic resistance a growing problem. Once regarded as constituting the class Schizomycetes, bacteria are now classified as prokaryotes. Unlike cells of animals and other eukaryotes, bacterial cells do not contain a nucleus and these evolutionary domains are called Bacteria and Archaea. The ancestors of modern bacteria were unicellular microorganisms that were the first forms of life to appear on Earth, for about 3 billion years, most organisms were microscopic, and bacteria and archaea were the dominant forms of life. In 2008, fossils of macroorganisms were discovered and named as the Francevillian biota, however, gene sequences can be used to reconstruct the bacterial phylogeny, and these studies indicate that bacteria diverged first from the archaeal/eukaryotic lineage. Bacteria were also involved in the second great evolutionary divergence, that of the archaea, here, eukaryotes resulted from the entering of ancient bacteria into endosymbiotic associations with the ancestors of eukaryotic cells, which were themselves possibly related to the Archaea
. PMID 21852539.