(en″dŏ-mē′trē-ŭm) [endo- + 1metro- + -ium] The mucous membrane that lines the uterus. It consists of two highly vascular layers of areolar connective tissue: the basilar layer, which is adjacent to the myometrium; and the functional layer, which is adjacent to the uterine cavity. Simple columnar epithelium forms the surface of the functional layer and the simple tubular uterine glands. Straight arteries supply blood to the basilar layer; spiral arteries supply the functional layer. Both estrogen and progesterone stimulate the growth of endometrial blood vessels.
Beginning with menarche and ending at menopause, the uterine endometrium passes through cyclical changes that constitute the menstrual cycle. These changes are related to the development and maturation of the graafian follicle in the ovary, the discharge of the ovum, and the subsequent development of the corpus luteum in the ovary.
If the ovum is not fertilized or the zygote not implanted, the functional layer of the endometrium is shed in menstruation.
The cycle then begins again, with the functional layer regenerated by the basilar layer.
Following implantation of the zygote, the endometrium becomes the maternal portion of the placenta; it fuses with the chorion of the embryo. After birth, the uterine lining is shed. SEE: fertilization for illus.
proliferative e. Endometrial hypertrophy due to estrogen stimulation during the preovulatory phase of the menstrual cycle. This condition is detected through endometrial biopsy.
secretory e. Histological changes in the endometrium due to the effects of postovulatory progesterone secretion by the corpus luteum. SEE: luteal phase defect; menstrual cycle. endometrial (en″dŏ-mē′trē-ăl), adj.
(en′dŏ-morf″) [endo- + -morph] A person with a body build marked by predominance of tissues derived from the endoderm. The body is pear shaped, often with significant adipose tissues in the upper arms, abdomen, and thighs. SEE: ectomorph; mesomorph; somatotype.
(ĕn″dō-mī-ō-kăr-dī′ tĭs) [″ + mys, muscle, + kardia, heart, + itis, inflammation] Inflammation of the endocardium and myocardium.
(en″do-mī″ŏ-mē″trīt′ĭs) [endo- + myometritis] Endometriosis.
(en″dŏ-miz′ē-ă, en″dŏ-miz′ ē-ŭm) pl. endomysia [endo- + mys, mouse, muscle + -ium] A thin sheath of connective tissue, consisting principally of reticular fibers, that invests each striated muscle fiber and binds the fibers within a fasciculus.
(ĕn′dō-nāz′ăl) Inside the nose.
(en″dŏ-noor′ē-ŭm) [endo- + neur- + -ium] A delicate connective tissue sheath that surrounds nerve fibers within a fasciculus. SYN: Henle sheath.
(en″dō-noo′klē-ās″, -nū′) [endo- + onuclease] An enzyme that cleaves the ends of polynucleotides.
restriction e. Restriction enzyme.