body cavity(redirected from Acoelomates)
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the collective visceral cavity of the trunk (thoracic cavity plus abdominopelvic cavity), bounded by the superior thoracic aperture above, the pelvic floor below, and the body walls (parietes) in between.
1. See coelom.
2. Any of the cavities of the body that adjoin external orifices, such as the mouth or rectum.
any of the spaces in the human body that contain organs. One major cavity, the thoracic cavity, is subdivided into a pericardial and two pleural cavities.
body cavityAny space in the body that does not freely communicate with the outside. Body cavities are covered with specialised lining cells—e.g., mesothelial cells in the pericardium, peritoneum and pleura.
Body cavity types
• Major—Pericardial, pleural, peritoneal, cerebrospinal.
• Minor—Amniotic, anterior chamber of the eye, cul de sac, hydrocele, oral cavity, synovial, vitreous.
bod·y cav·i·ty(bod'ē kav'i-tē)
1. Any hollow space within the body. See: illustration
2. A hidden body space that is accessible from the outside, e.g., rectum or vagina. Referred to in “body cavity search for contraband”.
3. Derivatives of the coelom, i.e., the pericardial, peritoneal, and plural sacs. See: coelom
See also: cavity
body cavitythe space within the body of most animals in which the gut and various organs are suspended. It normally contains fluid and is derived embryologically in different ways in different groups of animals. Absent in PLATYHELMINTHS and NEMERTINE worms, it is derived from the COELOM in vertebrates and from the HAEMOCOEL in arthropods and molluscs. It occurs as an intercellular space in nematode worms.
1. the trunk, or animal frame, with its organs.
2. the largest and most important part of any organ.
3. any mass or collection of material.
see ketone bodies.
formed in degenerating myelin sheaths. Each contains a fragment of myelin apparently undergoing enzymatic digestion around a fragment of degenerating axon.
see corpus fimbriatum.
see body fluids.
a 3-5 mm glycogen-rich body in the dorsal surface of the lumbosacral enlargement of the spinal cord in birds.
geniculate b's (lateral)
two metathalamus eminences, one on each side just lateral to the medial geniculate bodies, marking the termination of the optic tract.
geniculate b's (medial)
two metathalamus eminences, one on each side, just lateral to the superior colliculi, concerned with hearing.
Heinz body, Heinz-Ehrlich body
a dark staining refractile body of erythrocytes, consisting of denatured hemoglobin. See also Heinz body anemia.
see howell-jolly bodies.
either of the pair of small spherical masses in the interpeduncular fossa of the midbrain, forming part of the hypothalamus.
see body weight.
any of the osmiophilic, lipid-rich, layered bodies found in the type II alveolar cells of the lung.
eosinophilic, oval or round inclusion bodies in the cytoplasm of neurones of animals dead of rabies.
see olive (2).
dark, basophilic, iron-containing granules seen in erythrocytes (siderocytes). Occur in hemolytic anemia.
enclaves of chromaffin cells near the sympathetic ganglia along the abdominal aorta, which secrete catecholamines during prenatal and early postnatal life, aiding the adrenal medulla. Tumors of these structures produce clinical signs similar to those of pheochromocytoma.
paracloacal vascular body
a small patch of vascular tissue in the wall of the urodeum in birds.
pair of bodies flanking the phallus of the male bird; participate in the insemination of the hen.
see corpora quadrigemina.
see corpus striatum.
body surface area (BSA)
the total surface area of the body. Used to calculate drug dosages, particularly in the use of toxic drugs such as those used in cancer chemotherapy. This minimizes errors introduced by variations in distribution, metabolism and excretion of the drug. Several equations can be used to express the area, based on body weight, but conversion tables are usually used. See Table 21.
transverse ridge crossing the ventral surface of the medulla oblongata.
the transparent gel filling the posterior segment of the eyeball between the lens and retina. Called also vitreous and vitreous humor.
see body weight.