BIOL 240W 1st Edition Lecture 28Outline of Current LectureI. OvulationII. MenstruationIII. EstrogenIV. ConceptionV. Ovulation (Tuesday)VI. Follicular PhaseCurrent LectureMONDAY LECTUREI. Ovulationa. Luteal phase- first two weeks follicular phaseb. Oocyte is developing- proceeding through meiosisc. Support cells going through mitosisi. Follicle is getting bigger and biggerd. Exponential rise in estrogen occurs during this time (more follicle cells make more estrogen)e. Peak critical level of estrogen during follicular phase occursi. Triggers surge of FSH and LH which then triggers ovulation. Remaining follicle stays behindf. Luteal phase occursi. Corpus luteum cells were making estrogen, but now are making both estrogen and progesterone. ii. Progesterone rises and rises. iii. Corpus luteum has self destruct date- about 10 days after ovulation (apoptosis)iv. Once it dies, estrogen and progesterone levels fall and the whole cycle starts againII. Menstruationa. Endometriumi. Lines the inside of the uterusii. Estrogen and progesterone are stimulus to line inside of uterus and makes it thicker and thicker. 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.b. While the ovarian cycle involves changes in the ovaries, menstrual cycle involves changes in the uterusc. Three phasesd. Menses, proliferative phase, secretory phasee. Proliferative phasei. Right after woman stops previous menstruationii. Estrogen triggers cells to undergo mitosis, increased vascularization to add bloodvessels to support increase in cellsiii. Estrogen is coming from the folliclesiv. Cells are adding progesterone receptorsf. Secretory phasei. Progesterone-controlled (mostly)ii. More mitosis, thicker endometrium liningIII. Different types of estrogena. Estradiol, estriol, estroneb. Maintain primary and secondary sex characteristicsi. Primary- ovaries, uterus, oviducts, vaginal canal,ii. Secondary- breast and nipple, distribution of body fat, flare of pelvisiii. Libido and pubic/axillary hair controlled by andogrens- adrenal gland and ovariesIV. Conception a. Occurs in the oviductb. About 24 hours later, the zygote starts to dividei. Rapid cell division is called cleavagec. Day 3: morula forms, which is a ball of cells. Becomes hollowd. Day 6: blastocyst is a hollow ball of cellsi. Produces human chorionic gonadotropin (hcg)ii. Day 7: blastocysts implants into wall of uterus (endometrial lining)iii. 7-12: tophoblasts dissolve away layers of endometrium (which will heal and go back)1. trophoblast cells + epiblast cells + endometrial cells will form the placenta (organ made from mom and baby)iv. Inner cell mass: has epiblast cells that form a border on top of hollow area calledhypoblast cellsTUESDAY LECTUREV. Ovulationa. Egg cell initially frozen in prophase oneb. Within the first two weeks, goes through meiosis one and metaphase II inside ovaryc. Surrounding red cells are follicle cells and they secrete hormonesVI. Follicular phasea. Rising levels of gnRH tell anterior pituitary to release LH and FSH. Both tell follicle to grow and mature, follicles go through mitosis and egg cell goes through meiosisb. Follicle cells produce a little bit of estrogeni. Differing levels of estrogen (3 levels) signal anterior pituitary to produce different responses1. Small amount of estrogen signals the production of LH and FSH, but inhibits the release of the produced hormones2. Follicles grow, now estrogen levels produced are normal. Normal levels trigger the release of stored up LH and FSHii. Surge of LH triggers ovulationiii. Follicle is ruptured, and these cells are called the corpus luteum1. Corpus luteum takes over estrogen and progesterone production2. Also produces inhibin- does not let other follicles develop in the chance of fertilization of the previously released egg3. Corpus luteum degenerates if fertilization does not
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