1.
Ted Nugent
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Theodore Anthony Ted Nugent is an American musician and political activist. Nugent initially gained fame as the lead guitarist of the Amboy Dukes, after playing with the Amboy Dukes, he embarked on a solo career. Nugent is also noted for political views, his lifelong stance against drug and alcohol abuse and advocacy of hunting. He is a member of the National Rifle Association and a strong supporter of the Republican Party. Nugent was born the third of four siblings in Redford, Michigan, He moved to Palatine, Illinois as a teenager, raised Catholic, Nugent has mentioned his ties with Catholicism many times during interviews, and has stated that he regularly attends church. He attended William Fremd High School in Palatine, Illinois, then transferred after his year to St. Viator High School in Arlington Heights. Nugent has released more than 34 albums and has sold a total of 30 million records. He was known throughout his career in the 1970s for using Fender amps, a large part of his signature sound. Nugents 2005 plans involved a tour with country music singer-songwriter Toby Keith, Nugent toured with local Detroit musician Alex Winston during the summers of 2007 and 2008. On July 4,2008, at the DTE Energy Music Theater in Clarkston, Michigan, Ted Nugent played his 6, Derek St. Holmes, Johnny Bee Badanjek, and Nugents guitar teacher from 1958, Joe Podorsek, all jammed on stage with Nugent for various tunes. The Cellars house band at the time had been the Shadows of Knight, the Amboy Dukes second single was Journey to the Center of the Mind, which featured lyrics written by the Dukes second guitarist Steve Farmer. Nugent, an ardent anti-drug campaigner, has claimed that he had no idea that this song was about drug use. The Amboy Dukes, Journey to the Center of the Mind, Migration, on April 5,1968, Nugent along with a group of musicians paid tribute to Martin Luther King by having a folk, rock and blues jam session. Joni Mitchell played first, followed by Buddy Guy, Cactus, other musicians who participated were BB King and Al Kooper. After settling down on a ranch in Michigan in 1973, Nugent signed a deal with Frank Zappas DiscReet Records label. The following year, Tooth Fang & Claw established a fan base for Nugent, personnel changes nearly wrecked the band, which became known as Ted Nugent & the Amboy Dukes. Nugent reunited with the members of the Amboy Dukes at the 2009 Detroit Music Awards. The psychedelic band received a distinguished achievement honor at the event, the Dukes also played together at the ceremony, marking their first public performance in more than 30 years
2.
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
3.
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
4.
Cat
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The domestic cat is a small, typically furry, carnivorous mammal. They are often called house cats when kept as pets or simply cats when there is no need to distinguish them from other felids. Cats are often valued by humans for companionship and for their ability to hunt vermin, there are more than 70 cat breeds, though different associations proclaim different numbers according to their standards. Cats are similar in anatomy to the felids, with a strong flexible body, quick reflexes, sharp retractable claws. Cat senses fit a crepuscular and predatory ecological niche, cats can hear sounds too faint or too high in frequency for human ears, such as those made by mice and other small animals. They can see in near darkness, like most other mammals, cats have poorer color vision and a better sense of smell than humans. Cats, despite being solitary hunters, are a species and cat communication includes the use of a variety of vocalizations. Cats have a high breeding rate, under controlled breeding, they can be bred and shown as registered pedigree pets, a hobby known as cat fancy. Failure to control the breeding of pet cats by neutering, as well as the abandonment of former household pets, has resulted in numbers of feral cats worldwide. In certain areas outside cats native range, this has contributed, along with destruction and other factors. Cats have been known to extirpate a bird species within specific regions, a genetic study in 2007 concluded that domestic cats are descended from Near Eastern wildcats, having diverged around 8,000 BC in the Middle East. As of a 2007 study, cats are the second most popular pet in the US by number of pets owned, in a 2010 study they were ranked the third most popular pet in the UK, after fish and dogs, with around 8 million being owned. The domestic cat is believed to have evolved from the Near Eastern wildcat, the felids are a rapidly evolving family of mammals that share a common ancestor only 10–15 million years ago and include lions, tigers, cougars and many others. Within this family, domestic cats are part of the genus Felis, members of the genus are found worldwide and include the jungle cat of southeast Asia, European wildcat, African wildcat, the Chinese mountain cat, and the Arabian sand cat, among others. The domestic cat was first classified as Felis catus by Carl Linnaeus in the 10th edition of his Systema Naturae published in 1758, because of modern phylogenetics, domestic cats are usually regarded as another subspecies of the wildcat, F. silvestris. This has resulted in mixed usage of the terms, as the cat can be called by its subspecies name. Wildcats have also referred to as various subspecies of F. catus, but in 2003. The most common name in use for the cat remains F. catus
5.
Toledo, Ohio
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Toledo is a city in and the county seat of Lucas County, Ohio, United States. Toledo is in northwest Ohio, at the end of Lake Erie bordering the state of Michigan. The city was founded by United States citizens in 1833 on the west bank of the Maumee River and it was re-founded in 1837, after conclusion of the Toledo War, when it was incorporated in Ohio. After construction of the Miami and Erie Canal, Toledo grew quickly and it has since become a city with an art community, auto assembly businesses, education, healthcare, and local sports teams. The citys glass industry has earned it the nickname, The Glass City, the population of Toledo as of the 2010 Census was 287,208, making it the 71st-largest city in the United States. It is the fourth most populous city in the U. S. state of Ohio after Columbus, Cleveland, and Cincinnati. The Toledo metropolitan area had a 2010 population of 651,429, and was the sixth-largest metropolitan area in the state of Ohio, behind Cleveland, Columbus, Cincinnati, Dayton, and Akron. Varying cultures of indigenous peoples lived along the rivers and lakefront of what is now northwestern Ohio for thousands of years, when the city of Toledo was preparing to pave its streets, it surveyed two prehistoric semicircular earthworks, presumably for stockades. One was at the intersection of Clayton and Oliver streets on the bank of Swan Creek. Such earthworks were typical of mound-building peoples and this region was part of a larger area controlled by the historic tribes of the Wyandot and the people of the Council of Three Fires. The first European to visit the area was Étienne Brûlé, a French-Canadian guide and explorer, the French established trading posts in the area by 1680 to take advantage of the lucrative fur trade. The Odawa moved from Manitoulin Island and the Bruce Peninsula at the invitation of the French and they settled an area extending into northwest Ohio. By the early 18th century, the Odawa occupied areas along most of the Maumee River to its mouth and they served as middlemen between the French and tribes further to the west and north. The Wyandot occupied central Ohio, and the Shawnee and Lenape occupied the southern areas, the area was not settled by European-Americans until 1795 and after. They were finally defeated in 1794 at the Battle of Fallen Timbers and this loose affiliation of tribes included the Wyandot and Council of Three Fires. By a treaty in 1795, they ceded large areas of territory in Ohio to the United States, according to Charles E. Slocum, the American military built Fort Industry at the mouth of the Maumee about 1805, but as a temporary stockade. No official reports support the 19th-century tradition of its history there. The United States continued to work to extinguish land claims of Native Americans, in the Treaty of Detroit, the above four tribes ceded a large land area to the United States of what became southeastern Michigan and northwestern Ohio, to the mouth of the Maumee River
6.
Kitten
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A kitten, also known as a kitty or kitty cat, is a juvenile cat. After being born, kittens are totally dependent on their mother for survival, after about two weeks, kittens quickly develop and begin to explore the world outside the nest. After a further three to four weeks, they begin to eat food and grow adult teeth. Domestic kittens are highly social animals and enjoy human companionship, the word kitten derives from the Middle English word kitoun, which in turn came from the Old French chitoun or cheton. A feline litter usually consists of two to five kittens born after a gestation lasting between 64 and 67 days, with a length of 66 days. Kittens emerge in a sac called the amnion, which is bitten off, for the first several weeks, kittens are unable to urinate or defecate without being stimulated by their mother. They are also unable to regulate their temperature for the first three weeks, so kittens born in temperatures less than 27 °C can die from hypothermia if their mother does not keep them warm. The mothers milk is very important for the nutrition and proper growth. This milk transfers antibodies to the kittens, which protect them against infectious disease. Newborn kittens are unable to produce concentrated urine, and so have a high requirement for fluids. Kittens open their eyes about seven to ten days after birth, at first, the retina is poorly developed and vision is poor. Kittens are not able to see as well as adult cats until about ten weeks after birth, Kittens develop very quickly from about two weeks of age until their seventh week. They play-fight with their litter-mates and begin to explore the world outside the nest or den and they learn to wash themselves and others as well as play hunting and stalking games, showing their inborn ability as predators. These innate skills are developed by the mother or other adult cats. Later, the adult cats demonstrate hunting techniques for the kittens to emulate, as they reach three to four weeks old, the kittens are gradually weaned and begin to eat solid food, with weaning usually complete by six to eight weeks. Kittens generally begin to lose their baby teeth around three months of age, and have a set of adult teeth by nine months. Kittens live primarily on solid food after weaning, but usually continue to suckle from time to time until separated from their mothers, some mother cats will scatter their kittens as early as three months of age, while others continue to look after them until they approach sexual maturity. The sex of kittens is usually easy to determine at birth, by six to eight weeks they are harder to sex because of the growth of fur in the genital region
7.
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
8.
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
9.
Cat flea
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The cat flea is an extremely common parasitic insect whose principal host is the domestic cat, although a high proportion of the fleas found on dogs also belong to this species. The cat flea belongs to the insect order Siphonaptera which in its stage is an obligatory hematophage. The cat flea affects both the cat and the dog worldwide, the cat flea can also maintain its life cycle on other carnivores and on omnivores, but these are only chosen when more acceptable hosts become unavailable. Adult cat fleas do not willingly leave their hosts, and inter-animal transfer of adult fleas is rare except in animals that share sleeping quarters, a flea which becomes separated from its host will often die within hours from starvation. Fleas go through four life stages of egg, larva, pupa. Adult fleas must feed on blood before they can become capable of reproduction, flea populations are distributed with about 50% eggs, 35% larvae, 10% pupae, and 5% adults. The eggs are dispersed freely into the environment, within two to seven weeks a certain proportion will then hatch into larvae. The larva of the cat flea has an appearance and is ~2 mm in length. The larvae are negatively phototaxic/ phototropic, avoiding light and hiding in the substrate around them, the larvae require adequate ambient moisture and warmth, and will die at temperatures near freezing. Thus, the adult flea population continually feeds the larval population in the animals environment, flea larvae metamorphose through four stages before spinning a cocoon and entering the pupal stage. The cocoon is adhesive, and quickly acquires a coat of camouflage from surrounding dirt, the new flea begins feeding on host blood within minutes. A few fleas on adult dogs or cats cause little harm unless the host becomes allergic to substances in the fleas saliva, the disease that results is called flea allergy dermatitis. Small animals with large infestations can lose enough bodily fluid to fleas feeding that dehydration may result, cat fleas also may be responsible for disease transmission through humans, and have been suspected as transmission agents of plague. Cat fleas can transmit other parasites and infections to dogs and cats, the most prominent of these are Bartonella, murine typhus, and apedermatitis. The tapeworm Dipylidium caninum can be transmitted when an immature flea is swallowed by pets or humans, in addition, cat fleas have been found to carry Borrelia burgdorferi, the etiologic agent of Lyme disease, but their ability to transmit the disease is unclear. Since more than three-quarters of a life is spent somewhere other than on the host animal, it is not adequate to treat only the host. Thorough vacuuming, washing linens in hot water, and treating all hosts in the environment are essential. For any infestation, veterinarian aid will be necessary and when serious the services of a certified pest control company
10.
Tick
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Ticks are small arachnids, part of the order Parasitiformes. Along with mites, they constitute the subclass Acari, Ticks are ectoparasites, living by feeding on the blood of mammals, birds, and sometimes reptiles and amphibians. Ticks had evolved by the Cretaceous period, the most common form of fossilisation being immersed in amber, Ticks are widely distributed around the world, especially in warm, humid climates. Almost all ticks belong to one of two families, the Ixodidae or hard ticks, which are difficult to crush. Adults have ovoid or pear-shaped bodies which become engorged with blood when they feed, both families locate a potential host by odour or from changes in the environment. Ticks have four stages to their lifecycle, namely egg, larva, nymph, ixodid ticks have three hosts, taking at least a year to complete their lifecycle. Argasid ticks have up to seven stages, each one requiring a blood meal. Because of their habit of ingesting blood, ticks are vectors of at least twelve diseases that affect humans, fossilized ticks are known from the Cretaceous onwards, most commonly in amber. They most likely originated in the Cretaceous, with most of the evolution, the oldest example is an argasid bird tick from Cretaceous New Jersey amber. The younger Baltic and Dominican ambers have also yielded examples which can be placed in living genera, there are three families of ticks. The two large ones are the families of Ixodidae and Argasidae. The third is Nuttalliellidae, named for the bacteriologist George Nuttall and it comprises a single species, Nuttalliella namaqua, and is the most basal lineage. Ticks are closely related to the mites, within the subclass Acarina, RDNA analysis suggests that the Ixodidae are a clade, but that the Argasidae may be paraphyletic. The Ixodidae contains over 700 species of ticks with a scutum or hard shield. The Argasidae contains about 200 species, the genera accepted as of 2010 are Antricola, Argas, Nothoaspis, Ornithodoros and they have no scutum, and the capitulum is concealed beneath the body. The family Nuttalliellidae contains only a species, Nuttalliella namaqua. The phylogeny of the Ixodida within the Acari is shown in the cladogram, the Argasidae appear monophyletic in this study. Ticks are also distributed among host taxa, which include marsupial and placental mammals, birds, reptiles such as snakes, iguanas and lizards
11.
Neutrophil
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Neutrophil are the most abundant type of granulocytes and the most abundant type of white blood cells in most mammals. They form a part of the innate immune system. Its functionality varies in different animals and they are formed from stem cells in the bone marrow. They are short-lived and highly motile, or mobile, as they can enter parts of tissue where other cells/molecules wouldnt be able to enter otherwise, neutrophils may be subdivided into segmented neutrophils and banded neutrophils. They form part of the polymorphonuclear cells family together with basophils and eosinophils, the name neutrophil derives from staining characteristics on hematoxylin and eosin histological or cytological preparations. Whereas basophilic white blood cells stain dark blue and eosinophilic white blood cells stain bright red, normally, neutrophils contain a nucleus divided into 2–5 lobes. Neutrophils are a type of phagocyte and are found in the bloodstream. They migrate through the vessels, then through interstitial tissue, following chemical signals such as Interleukin-8, C5a, fMLP, Leukotriene B4. They are the predominant cells in pus, accounting for its whitish/yellowish appearance, Neutrophil granulocytes have an average diameter of 12-15 micrometers in peripheral blood smears. When analyzing neutrophils in suspension, neutrophils have a diameter of 8.85 µm. With the eosinophil and the basophil, they form the class of polymorphonuclear cells, the nucleus has a characteristic lobed appearance, the separate lobes connected by chromatin. The nucleolus disappears as the neutrophil matures, which is something that happens in only a few types of nucleated cells. In the cytoplasm, the Golgi apparatus is small, mitochondria and ribosomes are sparse, the cytoplasm also contains about 200 granules, of which a third are azurophilic. Neutrophils from women exhibit a small additional X chromosome structure, known as a neutrophil drumstick, neutrophils will show increasing segmentation as they mature. A normal neutrophil should have 3-5 segments, hypersegmentation is not normal, and occurs in some disorders, most notably vitamin B12 deficiency. This is noted on a review of the blood smear. Neutrophils are the most abundant white blood cells in humans, they account for approximately 50-70% of all blood cells. The stated normal range for human blood counts varies between laboratories, but a count of 2. 5–7.5 x 109/L is a standard normal range
12.
Lymphocyte
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A lymphocyte is one of the subtypes of white blood cell in a vertebrates immune system. Lymphocytes include natural killer cells, T cells, and B cells and they are the main type of cell found in lymph, which prompted the name lymphocyte. The three major types of lymphocyte are T cells, B cells and natural killer cells, lymphocytes can be identified by their large nucleus. T cells and B cells are the cellular components of the adaptive immune response. T cells are involved in cell-mediated immunity, whereas B cells are responsible for humoral immunity. The function of T cells and B cells is to recognize specific “non-self” antigens, once they have identified an invader, the cells generate specific responses that are tailored to maximally eliminate specific pathogens or pathogen-infected cells. B cells respond to pathogens by producing large quantities of antibodies which then neutralize foreign objects like bacteria, following activation, B cells and T cells leave a lasting legacy of the antigens they have encountered, in the form of memory cells. NK cells are a part of the immune system and play a major role in defending the host from both tumors and virally infected cells. NK cells distinguish infected cells and tumors from normal and uninfected cells by recognizing changes of a molecule called MHC class I. NK cells are activated in response to a family of cytokines called interferons, activated NK cells release cytotoxic granules which then destroy the altered cells. They were named natural killer cells because of the notion that they do not require activation in order to kill cells which are missing MHC class I. This notion seemed doubtful at the time but turned out to be correct, mammalian stem cells differentiate into several kinds of blood cell within the bone marrow. All lymphocytes originate, during this process, from a common lymphoid progenitor before differentiating into their distinct lymphocyte types, the differentiation of lymphocytes follows various pathways in a hierarchical fashion as well as in a more plastic fashion. The formation of lymphocytes is known as lymphopoiesis, following maturation, the lymphocytes enter the circulation and peripheral lymphoid organs where they survey for invading pathogens and/or tumor cells. The lymphocytes involved in adaptive immunity differentiate further after exposure to an antigen, they form effector, effector lymphocytes function to eliminate the antigen, either by releasing antibodies, cytotoxic granules or by signaling to other cells of the immune system. Microscopically, in a Wrights stained peripheral blood smear, a normal lymphocyte has a large, in normal situations, the coarse, dense nucleus of a lymphocyte is approximately the size of a red blood cell. Some lymphocytes show a clear perinuclear zone around the nucleus or could exhibit a clear zone to one side of the nucleus. Polyribosomes are a prominent feature in the lymphocytes and can be viewed with an electron microscope, the ribosomes are involved in protein synthesis, allowing the generation of large quantities of cytokines and immunoglobulins by these cells
. PMID 25356231.
