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 journal articles and books in the life sciences. It serves as a thesaurus that facilitates searching. Created and updated by the United States N ...

(MeSH), as defined by the United States National Library of Medicine (NLM). This list continues the information at

List of MeSH codes (A09) 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 (A08). Codes following these are ...

. Codes following these are found at List of MeSH codes (A11). For other MeSH codes, see List of MeSH codes. 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, along with epithelial tissue, muscle tissue, and nervous tissue. It develops from the mesenchyme derived from the mesoderm the middle embryonic germ layer. Connective tiss ...

* – adipose tissue * –

abdominal fat Adipose tissue, body fat, or simply fat is a loose connective tissue composed mostly of adipocytes. In addition to adipocytes, adipose tissue contains the stromal vascular fraction (SVF) of cells including preadipocytes, fibroblasts, vascular en ...

* – intra-abdominal fat * – subcutaneous fat, abdominal * – brown fat * – subcutaneous fat * – subcutaneous fat, abdominal * – bone and bones * –

bone matrix In osteology, the osteon or haversian system (; named for Clopton Havers) is the fundamental functional unit of much compact bone. Osteons are roughly cylindrical structures that are typically between 0.25 mm and 0.35 mm in diameter. Their ...

* – bony callus * – haversian system * – periosteum * –

cartilage Cartilage is a resilient and smooth type of connective tissue. In tetrapods, it covers and protects the ends of long bones at the joints as articular cartilage, and is a structural component of many body parts including the rib cage, the neck an ...

* – elastic cartilage * –

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 ai ...

* – granulation tissue * – cicatrix * –

subcutaneous tissue The subcutaneous tissue (), also called the hypodermis, hypoderm (), subcutis, 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 macr ...

–
epithelium Epithelium or epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. It is a thin, continuous, protective layer of compactly packed cells with a little intercellul ...

* –

basement membrane The basement 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 Epithelium, epithelial tissues including mesot ...

* –

bruch membrane Bruch's membrane is the innermost layer of the choroid of the eye. It is also called the ''vitreous lamina'' or ''Membrane vitriae'', because of its glassy microscopic appearance. It is 2–4 μm thick. Layers Bruch's membrane consists of five l ...

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

pericytes Pericytes (previously known as Rouget cells) are multi-functional mural cells of the microcirculation that wrap around the Endothelium, endothelial cells that line the Capillary, capillaries throughout the body. Pericytes are embedded in the basem ...

* – tunica intima * –

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

* –

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 between h ...

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

– exocrine glands

* –

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 poster ...

* – bulbourethral glands * – lacrimal apparatus * – mammary glands, animal * – mammary glands, human * – pancreas, exocrine * – prostate * – salivary glands * – parotid gland * – salivary ducts * – salivary glands, minor * –

sublingual gland The paired sublingual glands are major salivary glands in the mouth. They are the smallest, most diffuse, and the only unencapsulated major salivary glands. They provide only 3-5% of the total salivary volume. There are also two other types of sal ...

* –

submandibular gland The paired submandibular glands (historically known as submaxillary glands) are major salivary glands located beneath the floor of the mouth. They each weigh about 15 grams and contribute some 60–67% of unstimulated saliva secretion; on stimula ...

* – sebaceous glands * – meibomian glands * – sweat glands * – apocrine glands * –

eccrine glands Eccrine sweat glands (; from Greek ''ekkrinein'' 'secrete'; sometimes called merocrine glands) are the major sweat glands of the human body, found in virtually all skin, with the highest density in palm and soles, then on the head, but much less ...

– lymphoid tissue

* – adenoids * – bursa of fabricius * – germinal center * – dendritic cells, follicular * – lymph nodes * – germinal center * – dendritic cells, follicular * – peyer's patches * – spleen * – thymus gland * – tonsil

–
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. Bi ...

* –

* – basilar 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 the ...

* – extraembryonic membranes * –

allantois The allantois (plural ''allantoides'' or ''allantoises'') is a hollow sac-like structure filled with clear fluid that forms part of a developing amniote's conceptus (which consists of all embryonic and extraembryonic tissues). It helps the embryo ...

* –

amnion The amnion is a membrane that closely covers the human and various other embryos when first formed. It fills with amniotic fluid, which causes the amnion to expand and become the amniotic sac that provides a protective environment for the develo ...

* – chorioallantoic membrane * – chorion * –

chorionic villi Chorionic villi are villi that sprout from the chorion to provide maximal contact area with maternal blood. They are an essential element in pregnancy from a histomorphologic perspective, and are, by definition, a product of conception. Branche ...

* – yolk sac * – mucous membrane * – gastric mucosa * – chief cells, gastric * – enterochromaffin cells * – gastrin-secreting cells * – parietal cells, gastric * – somatostatin-secreting cells * – intestinal mucosa * – enterocytes * –

goblet cells Goblet cells are simple columnar epithelial cells that secrete gel-forming mucins, like mucin 5AC. The goblet cells mainly use the merocrine method of secretion, secreting vesicles into a duct, but may use apocrine methods, budding off their secre ...

* –

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 below the intestinal stem cells in the intest ...

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

* – nasal mucosa * –

* –

olfactory mucosa The olfactory mucosa is located in the upper region of the nasal cavity and is made up of the olfactory epithelium and the underlying lamina propria, connective tissue containing fibroblasts, blood vessels, Bowman's glands and bundles of fine axon ...

* – olfactory receptor neurons * – serous membrane * – pericardium * – peritoneum * – pleura

–
Muscle Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other types of muscl ...
s

* – muscle, skeletal * – sarcoplasmic reticulum * – muscle, smooth * – muscle, smooth, vascular * – tunica media * – myometrium * –

myocardium Cardiac muscle (also called heart muscle, myocardium, cardiomyocytes and cardiac myocytes) is one of three types of vertebrate muscle tissues, with the other two being skeletal muscle and smooth muscle. It is an involuntary, striated muscle that ...

– nerve tissue

* – ependyma * – myelin sheath * –

neurilemma Neurilemma (also known as neurolemma, sheath of Schwann, or Schwann's sheath) is the outermost nucleated cytoplasmic layer of Schwann cells (also called neurilemmocytes) that surrounds the axon of the neuron. It forms the outermost layer of the ner ...

* – ranvier's nodes * –

– organoids

– surgically created structures

* – colonic pouches * – skeletal muscle ventricle * –

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

s * – surgical flaps * – urinary reservoirs, continent ---- The list continues at List of MeSH codes (A11). {{MeSH codes A10