Reproductive Physiology — Flashcards

Flashcard 21: In _____ deficiency, a person is genotypically XY but has underdeveloped (ambiguous) male external genitalia with normal internal genitalia

Answer: 5-reductase

Flashcard 22: Gonadal males have testes that synthesize and secrete _____ and testosterone, which are required for development of the male phenotype

Answer: antimullerian hormone

Flashcard 23: Prolactin _____ ovulation and spermatogenesis by decreasing synthesis and release of GnRH

Answer: inhibits

Flashcard 24: _____ and pregnancy are the most important stimuli for prolactin secretion

Answer: Breast-feeding

Flashcard 25: Increased urinary frequency in pregnancy is due to hCG-stimulated production of _____, which increases GFR by increasing renal circulation

Answer: relaxin

Flashcard 26: Glucose _____ the placenta, whereas maternal insulin does not.

Answer: crosses

Flashcard 27: Prolactin is the major hormone responsible for _____ and also participates (with estrogen) in breast development

Answer: milk production (lactogenesis)

Flashcard 28: In utero, "breathing" occurs via aspiration and expulsion of _____; pulmonary vascular resistance remains high throughout gestation.

Answer: amniotic fluid

Extra: In the fetus, pulmonary vascular resistance (PVR) is high due to: 1. **Physical compression** of vessels by fluid-filled alveoli. 2. **Hypoxic pulmonary vasoconstriction** (the fetal lungs have low $P_{O2}$ because they are not used for gas exchange). At birth, the first breath replaces fluid with air and increases oxygen levels, leading to a rapid decrease in PVR.

Flashcard 29: At puberty, GnRH _____ its own receptor in the anterior pituitary, thus increasing sensitivity

Answer: up-regulates

Flashcard 30: Elevated levels of _____ in a non-pregnant patient is indicative of ovulation

Answer: progesterone