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progesterone

(Encyclopedia)progesterone prōjĕsˈtərōnˌ [key], female sex hormone that induces secretory changes in the lining of the uterus essential for successful implantation of a fertilized egg. A steroid, progesterone...

Rotifera

(Encyclopedia)Rotifera, phylum of predominantly free-living, microscopic, aquatic or semiterrestrial pseudocoelomates. Each rotifer has a head bearing a crown of cilia, the corona, at the anterior end; most rotifer...

salivary glands

(Encyclopedia)salivary glands sălˈəvârˌē [key], in humans, three pairs of glands that secrete the alkaline digestive fluid, saliva, into the mouth. Most animals have salivary glands that resemble those in hum...

eye

(Encyclopedia)CE5 Cross section of human eye eye, organ of vision and light perception. In humans the eye is of the camera type, with an iris diaphragm and variable focusing, or accommodation. Other types of ey...

cystitis

(Encyclopedia)cystitis sĭstīˈtĭs [key], common acute or chronic inflammation of the urinary bladder. The disease occurs primarily in young women and frequently results from bacterial invasion of the urethra fro...

chromosome

(Encyclopedia)chromosome krōˈməsōmˌ [key], structural carrier of hereditary characteristics, found in the nucleus of every cell and so named for its readiness to absorb dyes. The term chromosome is usually res...

hoopoe

(Encyclopedia)hoopoe ho͞oˈpo͞o, –pō [key], common name for a shy, solitary, Old World woodland bird, Upupa epops. Its body color ranges from cinnamon to chestnut, with white-barred, black wings and tail, and ...

autoimmune disease

(Encyclopedia)autoimmune disease, any of a number of abnormal conditions caused when the body produces antibodies to its own substances. In rheumatoid arthritis, a group of antibody molecules called collectively RF...

seasonal affective disorder

(Encyclopedia)seasonal affective disorder (SAD), recurrent fall or winter depression characterized by excessive sleeping, social withdrawal, depression, overeating, and pronounced weight gain. SAD effects an estima...

radioactive isotope

(Encyclopedia)radioactive isotope or radioisotope, natural or artificially created isotope of a chemical element having an unstable nucleus that decays, emitting alpha, beta, or gamma rays until stability is reache...