Physiology 206 1STedition Lecture 36Outline of Last Lecture I. DisordersII. Reproductive Systema. Male b. Female Diabetes Outline of Current Lecture I. OvulationII. Uterine CycleIII. EstrogenCurrent LectureOvum produced in ovaries, released into oviducts, fertilized, and transferred to uterus. Progesterone maintains conditions for pregnancy. Ovulation is triggered by a surge in LH levels. This maintains corpus luteum. A drop in LH allows for the follicular stage. Reuglation: hypothalamus stimulates LH and FSH secretion. Ovulation triggered by surge in LH. Ovarian cycle then gives rise to uterine/ menstrual cycle. Uterus-2 parts: myometrium( uterine muscle) and endometrium (uterine lining) Estrogen stimulates growth of both parts of uterus. Both increase in mass. Endometriumalso develops high levels of progesterone receptors. Estrogen is excreted during follicular phase, increases size and mass of endometrium. Progesterone inhibits uterine contractions. Is excreted during luteal phaseUterine Cycle- day 1 is first day of menstrual blood flowEstrogen and progesterone levels decrease sharply bc corpus luteum degenerates. Myometrium is contracted and endometrium secretes prostaglandinsProstaglandins-very powerful vasoconstrictors These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.In endometrium, constrict blood vessels and cut off blood flow, causing endometrium to dieStimulate contraction of smooth muscle-how they cut off blood flow. Stimulate myometrium. Dead endometrium is forcibly expelled from uterus( source of cramps )Total blood loss during a cycle is ~100ml (3oz)-after 1 week. Follicular secretion of estrogens ends menstrual flow.Proliferative phase starts again. -ovulation ends proliferative phase. Ovarian cycle is controlled by hypothalamus and controls the uterine
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