The following is a partial list of the "A" codes for

Medical Subject Headings Medical Subject Headings (MeSH) is a comprehensive controlled vocabulary for the purpose of indexing Academic journal, journal articles and books in the Life science, life sciences. It serves as a thesaurus of index terms that facilitates searc ...

(MeSH), as defined by the

United States National Library of Medicine The United States National Library of Medicine (NLM), operated by the United States federal government, is the world's largest medical library. Located in Bethesda, Maryland, the NLM is an institute within the National Institutes of Health. I ...

(NLM). This list continues the information at List of MeSH codes (A09). Codes following these are found at

List of MeSH codes (A11) The following is a partial list of the "A" codes for Medical Subject Headings (MeSH), as defined by the United States National Library of Medicine (NLM). This list continues the information at List of MeSH codes (A10). Codes following these are ...

. For other MeSH codes, see

List of MeSH codes The following is a list of the codes for MeSH (Medical Subject Headings), a comprehensive controlled vocabulary for the purpose of index (publishing), indexing journal articles and books in the life sciences. It is a product of the United States ...

. The source for this content is the set o
2006 MeSH Trees
from the NLM.

– tissues

–
connective tissue Connective tissue is one of the four primary types of animal tissue, a group of cells that are similar in structure, along with epithelial tissue, muscle tissue, and nervous tissue. It develops mostly from the mesenchyme, derived from the mesod ...

* –

adipose tissue Adipose tissue (also known as body fat or simply fat) is a loose connective tissue composed mostly of adipocytes. It also contains the stromal vascular fraction (SVF) of cells including preadipocytes, fibroblasts, Blood vessel, vascular endothel ...

* –

abdominal fat Abdominal obesity, also known as central obesity and truncal obesity, is the human condition of an excessive concentration of visceral fat around the stomach and abdomen to such an extent that it is likely to harm its bearer's health. Abdominal ...

* – intra-abdominal fat * – subcutaneous fat, abdominal * –

brown fat Brown adipose tissue (BAT) or brown fat makes up the adipose organ together with white adipose tissue (or white fat). Brown adipose tissue is found in almost all mammals. Classification of brown fat refers to two distinct cell populations with si ...

* –

subcutaneous fat The subcutaneous tissue (), also called the hypodermis, hypoderm (), subcutis, or superficial fascia, is the lowermost layer of the integumentary system in vertebrates. The types of cells found in the layer are fibroblasts, adipose cells, and ...

* – subcutaneous fat, abdominal * – bone and bones * – bone matrix * – bony callus * – haversian system * –

periosteum The periosteum is a membrane that covers the outer surface of all bones, except at the articular surfaces (i.e. the parts within a joint space) of long bones. (At the joints of long bones the bone's outer surface is lined with "articular cartila ...

* –

cartilage Cartilage is a resilient and smooth type of connective tissue. Semi-transparent and non-porous, it is usually covered by a tough and fibrous membrane called perichondrium. In tetrapods, it covers and protects the ends of long bones at the joints ...

* –

elastic cartilage Elastic cartilage, fibroelastic cartilage or yellow fibrocartilage is a type of cartilage present in the pinnae (auricles) of the ear giving it shape, provides shape for the lateral region of the external auditory meatus, medial part of the audi ...

* –

fibrocartilage Fibrocartilage consists of a mixture of white fibrous tissue and cartilaginous tissue in various proportions. It owes its inflexibility and toughness to the former of these constituents, and its elasticity to the latter. It is the only type of ...

* –

triangular fibrocartilage The triangular fibrocartilage complex (TFCC) is formed by the triangular fibrocartilage discus (TFC), the radioulnar ligaments (RULs) and the ulnocarpal ligaments (UCLs). Structure Triangular fibrocartilage disc The triangular fibrocartilage ...

* –

hyaline cartilage Hyaline cartilage is the glass-like (hyaline) and translucent cartilage found on many joint surfaces. It is also most commonly found in the ribs, nose, larynx, and trachea. Hyaline cartilage is pearl-gray in color, with a firm consistency and has ...

* –

elastic tissue Elastic fibers (or yellow fibers) are an essential component of the extracellular matrix composed of bundles of proteins (elastin) which are produced by a number of different cell types including fibroblasts, endothelial, smooth muscle, and air ...

* –

granulation tissue Granulation tissue is new connective tissue and microscopic blood vessels that form on the surfaces of a wound during the healing process. Granulation tissue typically grows from the base of a wound and is able to fill wounds of almost any size ...

* – cicatrix * –

subcutaneous tissue The subcutaneous tissue (), also called the hypodermis, hypoderm (), subcutis, or superficial fascia, is the lowermost layer of the integumentary system in vertebrates. The types of cells found in the layer are fibroblasts, adipose cells, and ma ...

–
epithelium Epithelium or epithelial tissue is a thin, continuous, protective layer of cells with little extracellular matrix. An example is the epidermis, the outermost layer of the skin. Epithelial ( mesothelial) tissues line the outer surfaces of man ...

* –

basement membrane The basement membrane, also known as base membrane, is a thin, pliable sheet-like type of extracellular matrix that provides cell and tissue support and acts as a platform for complex signalling. The basement membrane sits between epithelial tis ...

* – bruch membrane * –

endothelium The endothelium (: endothelia) is a single layer of squamous endothelial cells that line the interior surface of blood vessels and lymphatic vessels. The endothelium forms an interface between circulating blood or lymph in the lumen and the r ...

* – endothelium, corneal * – endothelium, lymphatic * – endothelium, vascular * –

pericytes Pericytes (formerly called Rouget cells) are multi-functional mural cells of the microcirculation that wrap around the endothelial cells that line the capillaries throughout the body. Pericytes are embedded in the basement membrane of blood capil ...

* –

tunica intima The tunica intima (Neo-Latin "inner coat"), or intima for short, is the innermost tunica (biology), tunica (layer) of an artery or vein. It is made up of one layer of endothelium, endothelial cells (and macrophages in areas of disturbed blood flo ...

* –

epidermis The epidermis is the outermost of the three layers that comprise the skin, the inner layers being the dermis and Subcutaneous tissue, hypodermis. The epidermal layer provides a barrier to infection from environmental pathogens and regulates the ...

* –

hair follicle The hair follicle is an organ found in mammalian skin. It resides in the dermal layer of the skin and is made up of 20 different cell types, each with distinct functions. The hair follicle regulates hair growth via a complex interaction betwee ...

* – epithelium, corneal * – pigment epithelium of eye * – seminiferous epithelium * –

urothelium Transitional epithelium is a type of stratified epithelium. Transitional epithelium is a type of tissue that changes shape in response to stretching (stretchable epithelium). The transitional epithelium usually appears cuboidal when relaxed and ...

–
exocrine glands Exocrine glands are glands that secrete substances onto an epithelial surface by way of a duct. Examples of exocrine glands include sweat, salivary, mammary, ceruminous, lacrimal, sebaceous, prostate and mucous. Exocrine glands are one of ...

* –

Bartholin's glands The Bartholin's glands (named after Caspar Bartholin the Younger; also called Bartholin glands or greater vestibular glands) are two pea-sized compound alveolar glandsManual of Obstetrics. (3rd ed.). Elsevier. pp. 1-16. . located slightly posteri ...

* –

bulbourethral glands The bulbourethral glands or Cowper's glands (named for English anatomist William Cowper (anatomist), William Cowper) are two small exocrine gland, exocrine and Male accessory gland, accessory glands in the reproductive system of many Mammal, male ...

* –

lacrimal apparatus The lacrimal apparatus is the physiological system containing the Orbit (anatomy), orbital structures for tears, tear production and drainage.Cassin, B. and Solomon, S. ''Dictionary of Eye Terminology''. Gainesville, Florida: Triad Publishing Co ...

* – mammary glands, animal * – mammary glands, human * – pancreas, exocrine * –

prostate The prostate is an male accessory gland, accessory gland of the male reproductive system and a muscle-driven mechanical switch between urination and ejaculation. It is found in all male mammals. It differs between species anatomically, chemica ...

* –

salivary glands The salivary glands in many vertebrates including mammals are exocrine glands that produce saliva through a system of Duct (anatomy), ducts. Humans have three paired major salivary glands (Parotid gland, parotid, Submandibular gland, submandibula ...

* –

parotid gland The parotid gland is a major salivary gland in many animals. In humans, the two parotid glands are present on either side of the mouth and in front of both ears. They are the largest of the salivary glands. Each parotid is wrapped around the m ...

* – salivary ducts * – salivary glands, minor * –

sublingual gland The sublingual gland (''glandula sublingualis'') is a seromucous polystomatic exocrine gland. Located underneath the oral diaphragm (''diaphragma oris''), the sublingual gland is the smallest and most diffuse of the three major salivary glands of ...

* –

submandibular gland The paired submandibular glands (historically known as submaxillary glands) are major salivary glands located beneath the floor of the mouth. In adult humans, they each weigh about 15 grams and contribute some 60–67% of unstimulated saliva sec ...

* –

sebaceous glands A sebaceous gland or oil gland is a microscopic exocrine gland in the skin that opens into a hair follicle to secrete an oily or waxy matter, called sebum, which lubricates the hair and skin of mammals. In humans, sebaceous glands occur in t ...

* –

meibomian glands Meibomian glands (also called tarsal glands, palpebral glands, and tarsoconjunctival glands) are sebaceous glands along the rims of the eyelid inside the tarsal plate. They produce meibum, an oily substance that prevents evaporation of the ey ...

* –

sweat glands Sweat glands, also known as sudoriferous or sudoriparous glands, , are small tubular structures of the skin that produce sweat. Sweat glands are a type of exocrine gland, which are glands that produce and secrete substances onto an epithelial sur ...

* –

apocrine glands Apocrine () is a term used to classify the mode of secretion of exocrine glands. In apocrine secretion, secretory cells accumulate material at their apical ends, often forming blebs or "snouts", and this material then buds off from the cells, ...

* – eccrine glands

–
lymphoid tissue The lymphatic system, or lymphoid system, is an organ system in vertebrates that is part of the immune system and complementary to the circulatory system. It consists of a large network of lymphatic vessels, lymph nodes, lymphoid organs, lympha ...

* –

adenoids In anatomy, the pharyngeal tonsil, also known as the nasopharyngeal tonsil or adenoid, is the superior-most of the tonsils. It is a mass of lymphoid tissue located behind the nasal cavity, in the roof and the posterior wall of the nasopharynx, ...

* –

bursa of fabricius In birds, the bursa of Fabricius (Latin: ''bursa cloacalis'' or ''bursa Fabricii'') is the site of hematopoiesis. It is a specialized organ that, as first demonstrated by Bruce Glick and later by Max Dale Cooper and Robert Good, is necessary fo ...

* –

germinal center Germinal centers or germinal centres (GCs) are transiently formed structures within B cell zone (follicles) in secondary lymphoid organs – lymph nodes, ileal Peyer's patches, and the spleen – where mature B cells are activated, prolifera ...

* – dendritic cells, follicular * –

lymph nodes A lymph node, or lymph gland, is a kidney-shaped Organ (anatomy), organ of the lymphatic system and the adaptive immune system. A large number of lymph nodes are linked throughout the body by the lymphatic vessels. They are major sites of lymphoc ...

* –

* – dendritic cells, follicular * –

peyer's patches Peyer's patches or aggregated lymphoid nodules are organized lymphoid follicles, named after the 17th-century Swiss anatomist Johann Conrad Peyer. * Reprinted as: * Peyer referred to Peyer's patches as ''plexus'' or ''agmina glandularum'' (cl ...

* –

spleen The spleen (, from Ancient Greek '' σπλήν'', splḗn) is an organ (biology), organ found in almost all vertebrates. Similar in structure to a large lymph node, it acts primarily as a blood filter. The spleen plays important roles in reg ...

* –

thymus gland The thymus (: thymuses or thymi) is a specialized primary lymphoid organ of the immune system. Within the thymus, T cells mature. T cells are critical to the adaptive immune system, where the body adapts to specific foreign invaders. The thymu ...

* –

tonsil The tonsils ( ) are a set of lymphoid organs facing into the aerodigestive tract, which is known as Waldeyer's tonsillar ring and consists of the adenoid tonsil (or pharyngeal tonsil), two tubal tonsils, two palatine tonsils, and the lingual t ...

–
membranes A membrane is a selective barrier; it allows some things to pass through but stops others. Such things may be molecules, ions, or other small particles. Membranes can be generally classified into synthetic membranes and biological membranes. B ...

* –

basilar membrane The basilar membrane is a stiff structural element within the cochlea of the inner ear which separates two liquid-filled tubes that run along the coil of the cochlea, the scala media and the scala tympani. The basilar membrane moves up and down ...

* – bruch membrane * –

descemet membrane Descemet's membrane ( or the Descemet membrane) is the basement membrane that lies between the corneal proper substance, also called stroma, and the endothelial layer of the cornea. It is composed of different kinds of collagen (Type IV and VIII ...

* –

glomerular basement membrane The glomerular basement membrane of the kidney is the basal lamina layer of the glomerulus. The glomerular endothelial cells, the glomerular basement membrane, and the filtration slits between the podocytes perform the filtration function of th ...

* – extraembryonic membranes * –

allantois The allantois ( ; : allantoides or allantoises) is one of the extraembryonic membranes arising from the yolk sac. It is a hollow sac-like structure filled with clear fluid that forms part of the developing conceptus in an amniote that helps the ...

* –

amnion The amnion (: amnions or amnia) is a membrane that closely covers human and various other embryos when they first form. It fills with amniotic fluid, which causes the amnion to expand and become the amniotic sac that provides a protective envir ...

* –

chorioallantoic membrane The chorioallantoic membrane (CAM), also known as the chorioallantois, is a highly vascularized membrane found in the eggs of certain amniotes like birds and reptiles. It is formed by the fusion of the mesodermal layers of two extra-embryonic memb ...

* –

chorion The chorion is the outermost fetal membrane around the embryo in mammals, birds and reptiles (amniotes). It is also present around the embryo of other animals, like insects and molluscs. Structure In humans and other therian mammals, the cho ...

* –

chorionic villi Chorionic villi are Wiktionary:villus, villi that sprout from the chorion to provide maximal contact area with maternal blood. They are an essential element in pregnancy from a histology, histomorphologic perspective, and are, by definition, a pr ...

* –

yolk sac The yolk sac is a membranous wikt:sac, sac attached to an embryo, formed by cells of the hypoblast layer of the bilaminar embryonic disc. This is alternatively called the umbilical vesicle by the Terminologia Embryologica (TE), though ''yolk sac' ...

* –

mucous membrane A mucous membrane or mucosa is a membrane that lines various cavities in the body of an organism and covers the surface of internal organs. It consists of one or more layers of epithelial cells overlying a layer of loose connective tissue. It ...

* –

gastric mucosa The gastric mucosa is the mucous membrane layer of the stomach, which contains the gastric pits, to which the gastric glands empty. In humans, it is about one mm thick, and its surface is smooth, soft, and velvety. It consists of simple secretor ...

* – chief cells, gastric * –

enterochromaffin cells Enterochromaffin (EC) cells (also known as Kulchitsky cells) are a type of enteroendocrine cell, and neuroendocrine cell. They reside alongside the epithelium lining the lumen of the digestive tract and play a crucial role in gastrointestinal r ...

* – gastrin-secreting cells * – parietal cells, gastric * – somatostatin-secreting cells * –

intestinal mucosa The gastrointestinal wall of the gastrointestinal tract is made up of four layers of specialised tissue. From the inner cavity of the gut (the lumen) outwards, these are the mucosa, the submucosa, the muscular layer and the serosa or adventitia. ...

* –

enterocytes Enterocytes, or intestinal absorptive cells, are simple columnar epithelial cells which line the inner surface of the small and large intestines. A glycocalyx surface coat contains digestive enzymes. Microvilli on the apical surface increase i ...

* –

goblet cells Goblet cells are simple columnar epithelial cells that secrete gel-forming mucins, like mucin 2 in the lower gastrointestinal tract, and mucin 5AC in the respiratory tract. The goblet cells mainly use the merocrine method of secretion, secreting ...

* –

paneth cells Paneth cells are cells in the small intestine epithelium, alongside goblet cells, enterocytes, and enteroendocrine cells. Some can also be found in the cecum and Vermiform appendix, appendix. They are located below the intestinal stem cells in th ...

* – mouth mucosa * – respiratory mucosa * – laryngeal mucosa * –

* – nasal mucosa * –

* –

olfactory mucosa The olfactory mucosa is the Neuroepithelial cell, neuroepithelial mucosa lining the roof and upper parts of the Nasal septum, septum and lateral wall of the nasal cavity which contains Bipolar neuron, bipolar neurons of the primary receptor neur ...

* –

olfactory receptor neurons An olfactory receptor neuron (ORN), also called an olfactory sensory neuron (OSN), is a sensory neuron within the olfactory system. Structure Humans have between 10 and 20 million olfactory receptor neurons (ORNs). In vertebrates, ORNs are Bi ...

* –

serous membrane The serous membrane (or serosa) is a smooth epithelial membrane of mesothelium lining the contents and inner walls of body cavity, body cavities, which secrete serous fluid to allow lubricated sliding (motion), sliding movements between opposing ...

* –

pericardium The pericardium (: pericardia), also called pericardial sac, is a double-walled sac containing the heart and the roots of the great vessels. It has two layers, an outer layer made of strong inelastic connective tissue (fibrous pericardium), ...

* –

peritoneum The peritoneum is the serous membrane forming the lining of the abdominal cavity or coelom in amniotes and some invertebrates, such as annelids. It covers most of the intra-abdominal (or coelomic) organs, and is composed of a layer of mesotheli ...

* –

pleura The pleurae (: pleura) are the two flattened closed sacs filled with pleural fluid, each ensheathing each lung and lining their surrounding tissues, locally appearing as two opposing layers of serous membrane separating the lungs from the med ...

–
Muscle Muscle is a soft tissue, one of the four basic types of animal tissue. There are three types of muscle tissue in vertebrates: skeletal muscle, cardiac muscle, and smooth muscle. Muscle tissue gives skeletal muscles the ability to muscle contra ...
s

* – muscle, skeletal * –

sarcoplasmic reticulum The sarcoplasmic reticulum (SR) is a membrane-bound structure found within muscle cells that is similar to the smooth endoplasmic reticulum in other cells. The main function of the SR is to store calcium ions (Ca2+). Calcium ion levels are kep ...

* – muscle, smooth * – muscle, smooth, vascular * –

tunica media The tunica media (Neo-Latin "middle coat"), or media for short, is the middle tunica (layer) of an artery or vein. It lies between the internal elastic lamina of the tunica intima on the inside and the tunica externa on the outside. Artery The ...

* –

myometrium The myometrium is the middle layer of the uterine wall, consisting mainly of uterine smooth muscle cells (also called uterine myocytes) but also of supporting stromal and vascular tissue. Its main function is to induce uterine contractions. Stru ...

* –

myocardium Cardiac muscle (also called heart muscle or myocardium) is one of three types of vertebrate muscle tissues, the others being skeletal muscle and smooth muscle. It is an involuntary, striated muscle that constitutes the main tissue of the wall o ...

–
nerve tissue Nervous tissue, also called neural tissue, is the main tissue component of the nervous system. The nervous system regulates and controls body functions and activity. It consists of two parts: the central nervous system (CNS) comprising the brain ...

* –

ependyma The ependyma is the thin neuroepithelial ( simple columnar ciliated epithelium) lining of the ventricular system of the brain and the central canal of the spinal cord. The ependyma is one of the four types of neuroglia in the central nervous s ...

* –

myelin sheath Myelin Sheath ( ) is a lipid-rich material that in most vertebrates surrounds the axons of neurons to insulate them and increase the rate at which electrical impulses (called action potentials) pass along the axon. The myelinated axon can be lik ...

* – neurilemma * – ranvier's nodes * – neurilemma

–
organoids An organoid is a miniaturised and simplified version of an Organ (anatomy), organ produced ''in vitro'' in three dimensions that mimics the key functional, structural, and biological complexity of that organ. It is derived from one or a few Cel ...

– surgically created structures

* – colonic pouches * – skeletal muscle ventricle * –

stoma In botany, a stoma (: stomata, from Greek language, Greek ''στόμα'', "mouth"), also called a stomate (: stomates), is a pore found in the Epidermis (botany), epidermis of leaves, stems, and other organs, that controls the rate of gas exc ...

s * – surgical flaps * – urinary reservoirs, continent ---- The list continues at

. {{MeSH codes A10

– tissues

– connective tissue Connective tissue is one of the four primary types of animal tissue, a group of cells that are similar in structure, along with epithelial tissue, muscle tissue, and nervous tissue. It develops mostly from the mesenchyme, derived from the mesod ...

– epithelium Epithelium or epithelial tissue is a thin, continuous, protective layer of cells with little extracellular matrix. An example is the epidermis, the outermost layer of the skin. Epithelial ( mesothelial) tissues line the outer surfaces of man ...

– exocrine glands Exocrine glands are glands that secrete substances onto an epithelial surface by way of a duct. Examples of exocrine glands include sweat, salivary, mammary, ceruminous, lacrimal, sebaceous, prostate and mucous. Exocrine glands are one of ...

– lymphoid tissue The lymphatic system, or lymphoid system, is an organ system in vertebrates that is part of the immune system and complementary to the circulatory system. It consists of a large network of lymphatic vessels, lymph nodes, lymphoid organs, lympha ...

– membranes A membrane is a selective barrier; it allows some things to pass through but stops others. Such things may be molecules, ions, or other small particles. Membranes can be generally classified into synthetic membranes and biological membranes. B ...

– Muscle Muscle is a soft tissue, one of the four basic types of animal tissue. There are three types of muscle tissue in vertebrates: skeletal muscle, cardiac muscle, and smooth muscle. Muscle tissue gives skeletal muscles the ability to muscle contra ...s

– nerve tissue Nervous tissue, also called neural tissue, is the main tissue component of the nervous system. The nervous system regulates and controls body functions and activity. It consists of two parts: the central nervous system (CNS) comprising the brain ...

– organoids An organoid is a miniaturised and simplified version of an Organ (anatomy), organ produced ''in vitro'' in three dimensions that mimics the key functional, structural, and biological complexity of that organ. It is derived from one or a few Cel ...