Immune system
The immune system is a host defense system comprising many biological structures and processes within an organism that protects against disease. To function properly, an immune system must detect a wide variety of agents, known as pathogens, from viruses to parasitic worms, distinguish them from the organism's own healthy tissue. In many species, the immune system can be classified into subsystems, such as the innate immune system versus the adaptive immune system, or humoral immunity versus cell-mediated immunity. In humans, the blood–brain barrier, blood–cerebrospinal fluid barrier, similar fluid–brain barriers separate the peripheral immune system from the neuroimmune system, which protects the brain. Pathogens can evolve and adapt, thereby avoid detection and neutralization by the immune system. Simple unicellular organisms such as bacteria possess a rudimentary immune system in the form of enzymes that protect against bacteriophage infections. Other basic immune mechanisms evolved in ancient eukaryotes and remain in their modern descendants, such as plants and invertebrates.
These mechanisms include phagocytosis, antimicrobial peptides called defensins, the complement system. Jawed vertebrates, including humans, have more sophisticated defense mechanisms, including the ability to adapt over time to recognize specific pathogens more efficiently. Adaptive immunity creates immunological memory after an initial response to a specific pathogen, leading to an enhanced response to subsequent encounters with that same pathogen; this process of acquired immunity is the basis of vaccination. Disorders of the immune system can result in inflammatory diseases and cancer. Immunodeficiency occurs when the immune system is less active than normal, resulting in recurring and life-threatening infections. In humans, immunodeficiency can either be the result of a genetic disease such as severe combined immunodeficiency, acquired conditions such as HIV/AIDS, or the use of immunosuppressive medication. In contrast, autoimmunity results from a hyperactive immune system attacking normal tissues as if they were foreign organisms.
Common autoimmune diseases include Hashimoto's thyroiditis, rheumatoid arthritis, diabetes mellitus type 1, systemic lupus erythematosus. Immunology covers the study of all aspects of the immune system; the immune system protects organisms from infection with layered defenses of increasing specificity. In simple terms, physical barriers prevent pathogens such as bacteria and viruses from entering the organism. If a pathogen breaches these barriers, the innate immune system provides an immediate, but non-specific response. Innate immune systems are found in all animals. If pathogens evade the innate response, vertebrates possess a second layer of protection, the adaptive immune system, activated by the innate response. Here, the immune system adapts its response during an infection to improve its recognition of the pathogen; this improved response is retained after the pathogen has been eliminated, in the form of an immunological memory, allows the adaptive immune system to mount faster and stronger attacks each time this pathogen is encountered.
Both innate and adaptive immunity depend on the ability of the immune system to distinguish between self and non-self molecules. In immunology, self molecules are those components of an organism's body that can be distinguished from foreign substances by the immune system. Conversely, non-self molecules are those recognized as foreign molecules. One class of non-self molecules are called antigens and are defined as substances that bind to specific immune receptors and elicit an immune response. Newborn infants have no prior exposure to microbes and are vulnerable to infection. Several layers of passive protection are provided by the mother. During pregnancy, a particular type of antibody, called IgG, is transported from mother to baby directly through the placenta, so human babies have high levels of antibodies at birth, with the same range of antigen specificities as their mother. Breast milk or colostrum contains antibodies that are transferred to the gut of the infant and protect against bacterial infections until the newborn can synthesize its own antibodies.
This is passive immunity because the fetus does not make any memory cells or antibodies—it only borrows them. This passive immunity is short-term, lasting from a few days up to several months. In medicine, protective passive immunity can be transferred artificially from one individual to another via antibody-rich serum. Microorganisms or toxins that enter an organism encounter the cells and mechanisms of the innate immune system; the innate response is triggered when microbes are identified by pattern recognition receptors, which recognize components that are conserved among broad groups of microorganisms, or when damaged, injured or stressed cells send out alarm signals, many of which are recognized by the same receptors as those that recognize pathogens. Innate immune defenses are non-specific, meaning these systems respond to pathogens in a generic way; this system does not confer long-lasting immunity against a pathogen. The innate immune system is the dominant system of host defense in most organisms.
Cells in innate immune system recognizes use pattern recognition receptors to recognize molecular structures that are produced by microbial pathogens. PRRs are germline-encoded host sensors, they are proteins expressed by cells of the innate immune system, such as dendritic cells, macrophages, m
Neck
The neck is the part of the body, on many vertebrates, that separates the head from the torso. It contains blood nerves that supply structures in the head to the body; these in humans include part of the esophagus, the larynx and thyroid gland, major blood vessels including the carotid arteries and jugular veins, the top part of the spinal cord. In anatomy, the neck is called by its Latin names, cervix or collum, although when used alone, in context, the word cervix more refers to the uterine cervix, the neck of the uterus, thus the adjective cervical may refer either to the uterine cervix. The neck contains vessels. In humans these structures include part of the esophagus, trachea and parathyroid glands, lymph nodes, the first part of the spinal cord. Major blood vessels include the jugular veins. Cervical lymph nodes surround the blood vessels; the thyroid gland and parathyroid glands are endocrine glands involved in the regulation of cellular metabolism and growth, blood calcium levels. The shape of the neck in humans is formed from the upper part of the vertebral column at the back, a series of cartilage that surrounds the upper part of the respiratory tract.
Around these sit soft tissues, including muscles, 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, the sternum; the large platysma, sternocleidomastoid muscles contribute to the shape at the front, the trapezius and lattissimus dorsi at the back. 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, at the back of the neck from the roots of C4-5; 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 cervical 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 curved in convex-forward fashion.
In addition to nerves coming from and within the human spine, the accessory nerve and vagus nerve both cranial nerves, travel down the neck. In the middle line below the chin can be felt the body of the hyoid bone, just below, the prominence of the thyroid cartilage called "Adam's apple", better marked in men than in women. Neck lines appear at a age as a development of skin wrinkles. Still, lower the cricoid cartilage is felt, while between this and the suprasternal notch, the trachea and the isthmus of the thyroid gland may be made out. At the side, the outline of the sternomastoid muscle is the most striking mark; the upper part of the former contains the submaxillary gland known as the submandibular glands, which lies just below the posterior half of the body of the jaw. 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; the eleventh or spinal accessory nerve corresponds to a line drawn from a point midway between the angle of the jaw and the mastoid process to the middle of the posterior border of the sterno-mastoid muscle and thence across the posterior triangle to the deep surface of the trapezius.
The external jugular vein can be seen through the skin. The anterior jugular vein is smaller, runs down about half an inch from the middle line of the neck; the clavicle or collar-bone forms the lower limit of the neck, laterally the outward slope of the neck to the shoulder is caused by the trapezius muscle. The neck supports the weight of the head and protects the nerves that carry sensory and motor information from the brain down to the rest of the body. In addition, the neck is flexible and allows the head to turn and flex in all directions. Disorders of the neck are a common source of pain; the neck has a great deal of functionality but is subject to a lot of stress. Common sources of neck pain include: Whiplash, strained a muscle or another soft tissue injury Cervical herniated disc Cervical spinal stenosis Osteoarthritis Vascular sources of pain, like arterial dissections or internal jugular vein thrombosis Cervical adenitis The neck appears in some of the earliest of tetrapod fossils, the functionality provided has led to its being retained in all land vertebrates as well as marine-adapted tetrapods such as turtles and penguins.
Some degree of flexibility is retained where the outside physical manifestation has been secondarily lost, as in whales and porpoises. A morphologically functioning neck appears among insects, its absence in fish and aquatic arthropods is notable, as many have life stations similar to a terrestrial or tetrapod counterpart, or could otherwise make use of the added flexibility. The word "neck" is sometimes used as a convenience to refer to the region behind the head in some snails, gastropod mollusks though there is no clear distinction between this area, the head area, the rest of the body. Throat Adam's apple Hickey Nape American Head and Neck Society The Anatomy Wiz. An Interactive Cross-Sectional Anatomy Atlas
Hip
In vertebrate anatomy, hip refers to either an anatomical region or a joint. The hip region is located lateral and anterior to the gluteal region, inferior to the iliac crest, overlying the greater trochanter of the femur, or "thigh bone". In adults, three of the bones of the pelvis have fused into the hip bone or acetabulum which forms part of the hip region; the hip joint, scientifically referred to as the acetabulofemoral joint, is the joint between the femur and acetabulum of the pelvis and its primary function is to support the weight of the body in both static and dynamic postures. The hip joints have important roles in retaining balance, for maintaining the pelvic inclination angle. Pain of the hip may be the result of numerous causes, including nervous, infectious, trauma-related, genetic; the proximal femur is covered by muscles and, as a consequence, the greater trochanter is the only palpable bony structure in the hip region. The hip joint is a synovial joint formed by the articulation of the rounded head of the femur and the cup-like acetabulum of the pelvis.
It forms the primary connection between the bones of the lower limb and the axial skeleton of the trunk and pelvis. Both joint surfaces are covered with a strong but lubricated layer called articular hyaline cartilage; the cuplike acetabulum forms at the union of three pelvic bones — the ilium and ischium. The Y-shaped growth plate that separates them, the triradiate cartilage, is fused definitively at ages 14–16, it is a special type of spheroidal or ball and socket joint where the spherical femoral head is contained within the acetabulum and has an average radius of curvature of 2.5 cm. The acetabulum grasps half the femoral ball, a grip augmented by a ring-shaped fibrocartilaginous lip, the acetabular labrum, which extends the joint beyond the equator; the joint space between the femoral head and the superior acetabulum is between 2 and 7 mm. The head of the femur is attached to the shaft by a thin neck region, prone to fracture in the elderly, due to the degenerative effects of osteoporosis.
The acetabulum is oriented inferiorly and anteriorly, while the femoral neck is directed superiorly and anteriorly. The transverse angle of the acetabular inlet can be determined by measuring the angle between a line passing from the superior to the inferior acetabular rim and the horizontal plane; the sagittal angle of the acetabular inlet is an angle between a line passing from the anterior to the posterior acetabular rim and the sagittal plane. It measures 7° at birth and increases to 17° in adults. Wiberg's centre-edge angle is an angle between a vertical line and a line from the centre of the femoral head to the most lateral part of the acetabulum, as seen on an anteroposterior radiograph; the vertical-centre-anterior margin angle is an angle formed from a vertical line and a line from the centre of the femoral head and the anterior edge of the dense shadow of the subchondral bone posterior to the anterior edge of the acetabulum, with the radiograph being taken from the false angle, that is, a lateral view rotated 25 degrees towards becoming frontal.
The articular cartilage angle is an angle formed parallel to the weight bearing dome, that is, the acetabular sourcil or "roof", the horizontal plane, or a line connecting the corner of the triangular cartilage and the lateral acetabular rim. In normal hips in children aged between 11 and 24 months, it has been estimated to be on average 20°, ranging between 18° to 25°, it becomes progressively lower with age. Suggested cutoff values to classify the angle as abnormally increased include:30° up to 4 months of age. 25° up to 2 years of age. The angle between the longitudinal axes of the femoral neck and shaft, called the caput-collum-diaphyseal angle or CCD angle measures 150° in newborn and 126° in adults. An abnormally small angle is known as an abnormally large angle as coxa valga; because changes in shape of the femur affects the knee, coxa valga is combined with genu varum, while coxa vara leads to genu valgum. Changes in CCD angle is the result of changes in the stress patterns applied to the hip joint.
Such changes, caused for example by a dislocation, changes the trabecular patterns inside the bones. Two continuous trabecular systems emerging on auricular surface of the sacroiliac joint meander and criss-cross each other down through the hip bone, the femoral head and shaft. In the hip bone, one system arises on the upper part of auricular surface to converge onto the posterior surface of the greater sciatic notch, from where its trabeculae are reflected to the inferior part of the acetabulum; the other system emerges on the lower part of the auricular surface, converges at the level of the superior gluteal line, is reflected laterally onto the upper part of the acetabulum. In the femur, the first system lines up with a system arising from the lateral part of the femoral shaft to stretch to the inferior portion of the femoral neck and head; the other system lines up with a system in the femur stretching from the medial part of the femoral shaft to the superior part of the femoral head. On the lateral side of the hip joint the fascia lata is strengthened to
Superficial temporal artery
In human anatomy, the superficial temporal artery is a major artery of the head. It arises from the external carotid artery when it splits into the superficial temporal artery and maxillary artery, its pulse can be felt above and in front of the tragus of the ear. The superficial temporal artery is the smaller of two end branches that split superiorly from the external carotid. Based on its direction, the superficial temporal artery appears to be a continuation of the external carotid, it begins within the parotid gland, behind the neck of the mandible, passes superficially over the posterior root of the zygomatic process of the temporal bone. The parietal branch of superficial temporal artery is a small artery in the head, it is larger than the frontal branch and curves upward and backward on the side of the head, lying superficial to the temporal fascia, joins with its fellow of the opposite side, with the posterior auricular and occipital arteries. The frontal branch of superficial temporal artery runs tortuously upward and forward to the forehead, supplying the muscles and pericranium in this region, anastomosing with the supraorbital and frontal arteries.
An estimate of the path of the nerve in the soft tissue of the temporal frontal branch using landmarks by Pitanguy. He describes a line starting from a point 0.5 cm below the tragus in the direction of the eyebrow, passing 1.5 cm above the lateral extremity of the eyebrow As it crosses the zygomatic process, it is covered by the auricularis anterior muscle, by a dense fascia. The superficial temporal artery joins with the supraorbital artery of the internal carotid artery; the superficial temporal artery is affected in giant-cell arteritis and biopsied if the diagnosis is suspected. Migraine attacks can occur; this article incorporates text in the public domain from page 559 of the 20th edition of Gray's Anatomy lesson4 at The Anatomy Lesson by Wesley Norman Angiogram of the superficial temporal artery Diagram at stchas.edu http://www.dartmouth.edu/~humananatomy/figures/chapter_47/47-2. HTM
Jaw
The jaw is any opposable articulated structure at the entrance of the mouth used for grasping and manipulating food. The term jaws is broadly applied to the whole of the structures constituting the vault of the mouth and serving to open and close it and is part of the body plan of most animals. In arthropods, the jaws are chitinous and oppose laterally, may consist of mandibles or chelicerae; these jaws are composed of numerous mouthparts. Their function is fundamentally for food acquisition, conveyance to the mouth, and/or initial processing. Many mouthparts and associate structures are modified legs. In most vertebrates, the jaws are bony or cartilaginous and oppose vertically, comprising an upper jaw and a lower jaw; the vertebrate jaw is derived from the most anterior two pharyngeal arches supporting the gills, bears numerous teeth. The vertebrate jaw originally evolved in the Silurian period and appeared in the Placoderm fish which further diversified in the Devonian; the two most anterior pharyngeal arches are thought to have become the jaw itself and the hyoid arch, respectively.
The hyoid system suspends the jaw from the braincase of the skull, permitting great mobility of the jaws. While there is no fossil evidence directly to support this theory, it makes sense in light of the numbers of pharyngeal arches that are visible in extant jawed vertebrates, which have seven arches, primitive jawless vertebrates, which have nine; the original selective advantage offered by the jaw may not be related to feeding, but rather to increased respiration efficiency. The jaws were used in the buccal pump that pumps water across the gills of fish or air into the lungs in the case of amphibians. Over evolutionary time the more familiar use of jaws, in feeding, was selected for and became a important function in vertebrates. Many teleost fish have modified jaws for suction feeding and jaw protrusion, resulting in complex jaws with dozens of bones involved; the jaw in tetrapods is simplified compared to fish. Most of the upper jaw bones have been fused to the braincase, while the lower jaw bones have been fused together into a unit called the mandible.
The jaw articulates via a hinge joint between the articular. The jaws of tetrapods exhibit varying degrees of mobility between jaw bones; some species have jaw bones fused, while others may have joints allowing for mobility of the dentary, quadrate, or maxilla. The snake skull shows the greatest degree of cranial kinesis, which allows the snake to swallow large prey items. In mammals the jaws are made up of the maxilla. In the ape there is a reinforcement to the lower jaw bone called the simian shelf. In the evolution of the mammalian jaw, two of the bones of the jaw structure were reduced in size and incorporated into the ear, while many others have been fused together; as a result, mammals show little or no cranial kinesis, the mandible is attached to the temporal bone by the temporomandibular joints. Temporomandibular joint dysfunction is a common disorder of these joints, characterized by pain and limitation of mandibular movement. Sea urchins possess unique jaws which display five-part symmetry, termed the Aristotle's lantern.
Each unit of the jaw holds a single, perpetually growing tooth composed of crystalline calcium carbonate. Muscles of mastication Otofacial syndrome Predentary Prognathism Rostral bone Jaw at the US National Library of Medicine Medical Subject Headings
Mount Sinai Hospital (Manhattan)
Mount Sinai Hospital, founded in 1852, is one of the oldest and largest teaching hospitals in the United States. It is located on the Upper East Side in the New York City borough of Manhattan, on the eastern border of Central Park stretching along Fifth Avenue, between East 98th Street and East 103rd Street; the entire Mount Sinai health system has over 7,400 physicians, as well as 3,815 beds, delivers over 16,000 babies a year. In 2018–19, the hospital was ranked 18th among the nearly 5,000 hospitals in the US by the U. S. News & World Report. At the time of the founding of the hospital in 1852, other hospitals in New York City discriminated against Jews both by not hiring them, by prohibiting them from being treated in the hospitals' wards. Philanthropist Sampson Simson founded the hospital to address the needs of New York City's growing Jewish immigrant community, it was the second Jewish hospital in the United States, after the Jewish Hospital, located in Cincinnati, established in 1847. The Jews' Hospital in the City of New York, as it was initially called, was built on West 28th Street in Manhattan, between Seventh and Eighth Avenues, on land donated by Simson.
It opened two years before Simson's death. Four years it was unexpectedly filled to capacity with soldiers injured in the American Civil War; the Jews' Hospital felt the effects of the escalating Civil War in other ways, as staff doctors and board members were called into service. Dr. Israel Moses served four years as lieutenant colonel in the 72nd New York Infantry Regiment; the New York Draft Riots of 1863 again strained the resources of the new hospital, as draft inequities and a shortage of qualified men increased racial tensions in New York City. As the Jews' Hospital struggled to tend to the many wounded, outside its walls over 100 men, children were killed in the riots. More and more, the Jews' Hospital was finding itself an integral part of the general community. In 1866, to reflect this new-found role, it changed its name. In 1872, the hospital moved uptown to the east side of Lexington Avenue, between East 66th and East 67th Streets. Now called Mount Sinai Hospital, the institution forged relationships with many physicians who made contributions to medicine, including Henry N. Heineman, Frederick S. Mandelbaum, Bernard Sachs, Charles A. Elsberg, Emanuel Libman, most Abraham Jacobi, known as the father of American pediatrics and a champion of construction at the hospital's new site on Manhattan's Upper East Side in 1904.
The hospital established a school of nursing in 1881. Created by Alma deLeon Hendricks and a small group of women, Mount Sinai Hospital Training School for Nurses was taken over by the hospital in 1895. In 1923, its name was changed to Mount Sinai Hospital School of Nursing; this school closed in 1971 after graduating 4,700 nurses—all women, except one man in the last class. An active alumnae association continues; the early 20th century saw the population of New York City explode. That, coupled with many new discoveries at Mount Sinai, meant that Mount Sinai's pool of doctors and experts was in increasing demand. A $1.35 million expansion of the 1904 hospital site raced to keep pace with demand. The opening of the new buildings was delayed by the advent of World War I. Mount Sinai responded to a request from the United States Army Medical Corps with the creation of Base Hospital No.3. This unit went to France in early 1918, treated 9,127 patients with 172 deaths: 54 surgical and 118 medical, the latter due to influenza and pneumonia.
Two decades with tensions in Europe escalating, a committee dedicated to finding placements for doctors fleeing Nazi Germany was founded in 1933. With the help of the National Committee for the Resettlement of Foreign Physicians, Mount Sinai Hospital became a new home for a large number of émigrés; when World War II broke out, Mount Sinai was the first hospital to throw open its doors to Red Cross nurses' aides. Meanwhile, the president of the medical board, George Baehr, M. D. was called by President Roosevelt to serve as the nation's Chief Medical Director of the Office of Civilian Defense. These wartime roles were eclipsed, when the men and women of Mount Sinai's 3rd General Hospital set sail for Casablanca, Morocco setting up a 1,000-bed hospital in war-torn Tunisia. Before moving to tend to the needs of soldiers in Italy and France, the 3rd General Hospital had treated more than 5,000 wounded soldiers. In 1963, the hospital created a medical school, in 1968 it welcomed the first students of the Mount Sinai School of Medicine, now the Icahn School of Medicine at Mount Sinai.
The 1980s had a $500 million hospital expansion, including the construction of the Guggenheim Pavilion, the first medical facility designed by I. M. Pei, its faculty has made significant contributions to gene therapy, immunotherapy, organ transplants, cancer treatments, minimally invasive surgery. Among the innovations at Mount Sinai were performing the first blood transplant into the vein of a fetus in 1986, the development of a technique for inserting radioactive seeds into the prostate to treat cancer in 1995. At Mount Sinai the staff performed the first successful composite tracheal transplant, performed at the hospital in 2005. Writing for The Boston Globe on 14 October 2007, Scott Allen reported the issue of patient abuse and problems with hu
Northern Europe
Northern Europe is a general term for the geographical region in Europe, north of the southern coast of the Baltic Sea, about 54°N. Narrower definitions may be based on other geographical factors such as ecology. A broader definition would include the area north of the Alps. Countries which are central-western, central or central-eastern are not considered part of either Northern or Southern Europe; when Europe was dominated by the Roman Empire, everything not near the Mediterranean region was termed Northern Europe, including southern Germany, all of the Low Countries, Austria. This meaning is still used today in some contexts, for example, discussions of the Northern Renaissance. Northern Europe might be defined as the British Isles, the peninsula of Jutland, the Baltic plain that lies to the east and the many islands that lie offshore from mainland Northern Europe and the main European continent. Nations included within this region are Denmark, the Faroe Islands, Iceland, Lithuania and Sweden, less the United Kingdom, the Republic of Ireland, northern Germany, northern Belarus and northwest Russia.
The area is mountainous, including the northern volcanic islands of Iceland and Jan Mayen, the mountainous western seaboard and Scandinavia, includes part of a large eastern plain, with Lithuania, Latvia and Finland. The entire region's climate is at least mildly affected by the Gulf Stream. From the west climates vary from maritime subarctic climates. In the north and central climates are subarctic or Arctic and to the east climates are subarctic and temperate/continental. Just as both climate and relief are variable across the region, so too is vegetation, with sparse tundra in the north and high mountains, boreal forest on the north-eastern and central regions temperate coniferous forests and temperate broadleaf forests growing in the south and temperate east. Countries included in their entirety within the region, by population count: United Kingdom 66,040,229 Sweden 10,067,744 Denmark 5,769,603 Finland 5,513,000 Norway 5,282,223 Ireland 4,813,608 Lithuania 2,827,721 Latvia 1,940,740 Estonia 1,317,800 Iceland 341,284Countries in Northern Europe have developed economies and some of the highest standards of living in the world.
They score on surveys measuring quality of life, such as the Human Development Index. Aside from the United Kingdom, they have a small population relative to their size, most of whom live in cities. Most peoples living in Northern Europe are traditionally Protestant Christians, although many are non-practicing. There are growing numbers of non-religious people and people of other religions Muslims, due to immigration. In the United Kingdom, there are significant numbers of Indian religions such as Hindus and Sikhs, due to the large South Asian diaspora; the quality of education in much of Northern Europe is rated in international rankings, with Estonia and Finland topping the list among the OECD countries in Europe. The Hansa group in the European Union comprises most of the Northern European states. Media related to Northern Europe at Wikimedia Commons
