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Related to internal environment: external environment
internal environmentthe medium in which all body cells are bathed and which maintains a constant environment (see HOMEOSTASIS), in terms of pH, osmotic pressure, etc.
situated or occurring within or on the inside; in anatomy, many structures formerly called internal are now termed medial.
internal abdominal abscess
see retroperitoneal abscess.
internal carotid artery arteritis
parasitic arteritis of the external carotid artery as it courses around the edge of the guttural pouch may lead to copious nasal bleeding in horses when the artery ruptures.
internal elastic membrane
a condensation of elastic fibers separating the tunica intima from the tunica media.
within the animal; includes blood pressure, circulating blood volume, tissue fluid volume, blood sugar level, tidal air volume, glomerular filtration rate.
immobilization of fractured bones by internal appliances as distinct from casts or external fixation. Includes intramedullary pins which run the length of the medullary cavity, transfixing pins that penetrate across the medullary cavity and are maintained in position by external bars or casts, and compression plating based on the use of special screws and plates.
internal inguinal ring
see abdominal ring (internal).
unshelled eggs are free in the peritoneal cavity, thought to have been delivered there by reverse peristalsis in the oviduct.
eggs are deposited in the peritoneal cavity and become walled off.
internal limiting membrane
a persistent fibrillar condensation of the vitreous body of the eye; it covers the retina and ciliary body.
internal parasitic mites
poultry cutaneous mites in a number of families are found in the trachea, air sacs and subcutaneous tissues. Includes Cytodites, Epidermoptes, Laminosioptes, Pneumonyssus, Rivoltsia and Sternastoma spp.
internal rate of return
the interest rate needed to discount future income in order to equate it with the present investment in a program.
repetitive base sequences within DNA which may be inverted (indirect) or non-inverted (direct).
internal root sheath
connective tissue sheath around the hair follicle; this part of the sheath extends only to the opening of sebaceous glands into the follicle. See also root sheath cuticle.
turkey internal hemorrhage
see dissecting aneurysm.
any reflux of intestinal contents which does not reach the mouth, e.g. abomasal reflux into the rumenoreticulum.