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pregnancy

(Encyclopedia)pregnancy, period of time between fertilization of the ovum (conception) and birth, during which mammals carry their developing young in the uterus (see embryo). The average duration of pregnancy in h...

fluke

(Encyclopedia)fluke, parasitic flatworm of the trematoda class, related to the tapeworm. Instead of the cilia, external sense organs, and epidermis of the free-living flatworms, adult flukes have sucking disks with...

drug poisoning

(Encyclopedia)drug poisoning, toxic effects caused by an administered drug. Worldwide more than 9 million natural and synthetic chemicals have been identified; fewer than 3000 cause more than 95% of acidental and d...

endocytosis

(Encyclopedia)endocytosis ĕnˌdōsītōˈsəs [key], in biology, process by which substances are taken into the cell. When the cell membrane comes into contact with a suitable food, a portion of the cell cytoplasm...

stimulant

(Encyclopedia)stimulant, any substance that causes an increase in activity in various parts of the nervous system or directly increases muscle activity. Cerebral, or psychic, stimulants act on the central nervous s...

transplantation, medical

(Encyclopedia)transplantation, medical, surgical procedure by which a tissue or organ is removed and replaced by a corresponding part, usually from another part of the body or from another individual. A life-saving...

Mollusca

(Encyclopedia)Mollusca məlŭsˈkə [key], taxonomic name for the one of the largest phyla of invertebrate animals (Arthropoda is the largest) comprising more than 50,000 living mollusk species and about 35,000 fos...

laminitis

(Encyclopedia)laminitis lămˌənīˈtĭs [key], also called founder, inflammation of the lamina, the innermost layer of the hoof wall in horses, ponies, and donkeys. Although the condition usually affects only the...

arapaima

(Encyclopedia)arapaima ărˌəpīˈmə [key], tropical fish, genus Arapaima, of the Amazon basin. Arapaimas are perhaps the largest of the strictly freshwater fishes, reportedly reaching a length of 15 ft (4.5 m), ...

nail, in anatomy

(Encyclopedia)nail, in anatomy, the horny outgrowth shielding the tip of the finger and the toe in humans and most other primates. The nail consists of dead cells pushed outward by dividing cells in the root, a fol...