BIO 241 1st Edition Lecture 32 Outline of Last Lecture I. Vagina II. Female reproductive cycleIII. Estrogen secretion and controlOutline of Current Lecture II. Female cycle phases IIII. Female cycle phases IIIV. Sexual responseCurrent LectureII. The average female cycle is about 28 days but can vary. The menses phase (the bleeding stage) lasts around 1-5 days. This causes greatly diminished blood estrogen and progesterone levels, the stratum functionalis is dead and shedding (bleeding), and low estrogen stimulates Gn-RF + FSH which initiates follicular development at the beginning of a new cycle. The preovulatory phase happens around day 6-13. New follicles develope and secrete estrogen, rising blood estrogen causes mitosis of stratum basalis which causes the rebuilding of the stratum functionalis. The ovary is in the follicular phase and the uterus is in the proliferative phase. Ovulation occurs around day 14. High estrogen stimulates Gn-RF + LH, thus stimulating ovulation and as a result the corpus luteum is formed. Postovulatory days occur from day 15-26.The corpus luteum produces estrogen + progesterone which makes the stratum functionalis become secretory so that it: 1. retains water 2. uterine glands secrete glycogen 3. spiral arterioles rapidly developThe ovary is in the luteal phase and the uterus is in the secretory phase. The ischemic phase occurs from days 27-28. The corpus luteum is dying so blood estrogen and progesterone levels drop. Spiral arterioles vasoconstrict for 6 hours at a time then vasodilate for 6 hours essentially forcing the stratum functionalis to die. This cycle is repeated monthly, unfortunately.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.III.IV. Both the male and female go through excitement, orgasm, and resolution. In men, they get erect and the bulbourethral gland lubricates the urethra for ejaculation. During orgasm, emission occurs where the prostate gland and seminal vesicles fill and instantaneously ejaculation occurs. During resolution, the penis gets soft which is called detumescence and theyhave a refractory period (reloading). In a female, lubrication also occurs from vaginal transudate(fluid seeping through tissue). The orgasm occurs and the contractions help pull sperm upward toward the uterus. There is no refractory period in women. In both genders, excitement is controlled by the parasympathetic nervous system and the rest is controlled by
View Full Document