relaxin re·lax·in (rĭ-lāk'sĭn)
A female hormone secreted by the corpus luteum that helps soften the cervix and relax the pelvic ligaments in childbirth.
a hormone produced by the ovaries during pregnancy that causes pelvic and cervical expansion and relaxation. It inhibits muscular contractions of the uterus that would cause natural abortion of the developing child, stimulates the growth of the glands in the breasts that are responsible for milk production, and increases the amount of water in the uterus. The hormone is found only in pregnant females, and its activities last only for 24 hours after birth.
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