FEMALE REPRODUCTIVE SYSTEM: EXAM 4

HORMONAL CYCLE Corpus luteum secretes ____________ and ____________ that inhibit hypothalamus via ___________ feedback o If fertilization CL _______ o If no fertilization CL ______

Corpus luteum secretes progesterone and estrogen atht inhibit hypothalamus via negative feedback o If fertilization CL lives o If no fertilization CL dies • If CL dies, declining estrogens and progesterone stimulate hypothalamus so whole cycle starts again

HORMONAL CYCLE Decreases in estrogen and progesterone cause the ____________ to release _________

Decreases in estrogen and progesterone cause the HYPOTHALAMUS to release GnRH

Describe Diploid (2N)

Diploid (2N) cells contain two complete sets of chromosomes and are produced via the process called mitosis. Most cells in the body are diploid and contain one complete set of chromosomes

HORMONAL CYCLE GnRH causes anterior pituitary to release:

FSH • Targets primordial follicle to resume meiosis I • Developing follicle releses estrogen (uterine prolifertation) LH • Surge causes ovulation (positive feedback of estrogen here triggers LH release)

Describe Haploid (1N)

Haploid (1n) contain one compete set of chromosomes and are a result of the process of meiosis. Gametes are haploid and have 23 chromosomes. This is important. When two gametes join at fertilization the newly formed cell will have the correct, 46 chromosomes.

1. Identify and describe the gross anatomy of the female reproductive system, including the gonads, ducts, accessory glands, associated support structures, and external genitalia.

IN OTHER CARDS

describe the two stages of meiosis

MEIOSIS I During interphase a diploid germinal cell replicates its DNA. Then, meiosis I occurs in four distinct stages: prophase I, metaphase I, anaphase I, telophase I. In prophase I the nuclear envelope disappears, the chromatin condenses into chromosomes, and the mitotic spindle forms. Each chromosome has 2 identical copies of the genetic material connected by a centromere and we call these "sister chromatids." Because this genetic material was copied from a diploid cell, that means there is half of the genetic material that came from the father and that other half from the mother. The "matching chromosomes" from each parent are called homologous chromosomes. (You have 22 pairs of these in every diploid cell in your body. The other two are either an X and a Y or two X chromosomes to make the full 46 count in a diploid cell.) In late prophase I, the homologous chromosomes pair up and exchange genetic material between "matching" portions of genetically different chromatids. (i.e., mother and father DNA change places on the chromosomes). We call this crossing-over. This step makes it such that the resulting chromosomes are not like each other and are not like the original cell from which they came. This is partly why there is so much genetic variation between people. Following prophase I, metaphase I occurs. This is where all of the genetic material aligns through the middle of the cell. Then, in anaphase I, one full set of chromosomes heads to each pole of the cell. Telophase I ensues and the cell divides to make two haploid cells (each with a duplicate copy of the 23 chromosomes attached at the centromere) with a new, rearranged genetic make-up. In other words, you have two cells that look pretty much like the end of normal interphase with sister chromatids ready to split. MEIOSIS II The same four phases occur in Meiosis II as Meiosis I, but we call them Prophase II, Metaphase II, Anaphase II, and Telophase II. Here the sister chromatids split and now you have 4 cells each with 23 chromosomes. If the above did not make sense because it really requires a semester's worth of study, here is the bottom line you need to understand...To produce gametes, a "parent" cell with 46 chromosomes replicates, rearranges the genetic material and then splits and then splits again to make 4 "daughter" cells each with 23 chromosomes.

describe a negative feedback system

Negative Feedback Systems are the more common ones in the body. This is where the result reverses what the stimulus was. Can you think of an example of negative feedback we've discussed already this semester? Blood pressure?

1. Identify and describe the gross anatomy of the ovary

OVARY female gonads that produce oocytes and sex steroid hormones (notably estrogen and progesterone) o Corpus luteum - transformed follicle after ovulation that secretes progesterone o Grafian follicle - fluid filled structure where the ova develops before ovulation o Primordial follicle - least developed ovarian follicles that consist of a single oocyte and a single layer of flat (squamous) granulosa cells o Corpus albicans - nonfunctional structure remaining in the ovarian stroma following structural and functional regression of the corpus luteum

describe ovulation

Ovulation is the term used to describe when the follicle ruptures and the oocyte is released. If fertilization doesn't happen in 12-24 hours, degeneration. If fertilization happens, meiosis II begins.

describe a postive feedback system

Positive Feedback Systems on the other hand intensify the original condition. Do you remember the example of childbirth from Chapter 1 in 2085?

describe progesterone

Progesterone is only present during the stable days of the monthly cycle. It is important in supporting a fertilized egg that has implanted in the uterine wall. Progesterone causes the endometrium to thicken a little, and to secrete nutrients for the anticipated embryo. It also makes cervical mucus thick and viscous. The "ferning" effect is not present. Again, the body at this point either has a fertilized egg or not. There is no need to make a hospitable environment for sperm. Progesterone also inhibits the release of GnRH, FSH, and LH. The effects of progesterone on pregnancy will be considered when we discuss pregnancy.

1. Identify and describe the gross anatomy of the Ovaries

The ovaries produce eggs and sex hormones. Their anatomy: Tunica albuginea - capsule Outer cortex - site of ovarian follicles Inner medulla - arteries and veins Follicles - developing ovum surrounded by follicular cells

describe the uterine cycle and list its steps

The uterine cycle aka menstrual cycle anticipates fertilization. Remember this is a cycle, so day 1 occurs right after day 28. 1- Endometrium sloughs off the first 5-7 days of the uterine cycle 2- Once this is done, the endometrial cells begin to proliferate again with glandular cells and blood vessels 3- At ovulation, the corpus luteum secretes progesterone and estrogen; additional thickening of the lining and secretion of glycogen 4- If no fertilization: The CL dies at ~12 days and cells lining uterus die and are sloughed OR 4- If fertilization: embryo produces HCG which signals CL to keep working

4. Identify and describe the histology of the uterine wall.

The uterine wall consists of an external serosa called the perimetrium, a middle muscular layer called the myometrium, and an inner mucosa called the endometrium MYOMETRIUM FUNCTION - The function of the myometrium is to produce the labor contractions that help to expel the fetus. ANATOMY - constitutes most of the wall - It is composed mainly of bundles of smooth muscle that sweep downward from the fundus and spiral around the body of the uterus - The myometrium is less muscular and more fibrous near the cervix; the cervix itself is almost entirely collagenous - The muscle cells of the myometrium are about 40 µm long immediately after menstruation, but they are twice this long at the middle of the menstrual cycle and 10 times as long in pregnancy ENDOMETRIUM FUNCTION -When pregnancy occurs, the endometrium is the site of attachment of the embryo and forms the maternal part of the placenta from which the fetus is nourished. ANATOMY - has a simple columnar epithelium, compound tubular glands, and a lamina propria populated by leukocytes, macrophages, and other cells - The superficial half to two-thirds of it, called the functional layer (stratum functionalis), is shed in each menstrual period. - The deeper layer, called the basal layer (stratum basalis), stays behind and regenerates a new functional layer in the next cycle LOOK UP PICTURE

1. Identify and describe the gross anatomy of the vagina

Vagina is the copulatory organ in the female o Muscular canal that is the entrance to the reproductive tract

1. Identify and describe the gross anatomy of the uterus

muscular hollow organ in which a fertilized egg develops into a fetus o Fallopian (uterine) tube - aka oviducts; ducts that facilitate transport of an ovulated oocyte to the uterus o Fundus - of the uterus) domed portion of the uterus that is superior to the uterine tubes o Body - middle section of the uterus o Cervix - elongate inferior end of the uterus where it connects to the vagina o Endometrium - inner lining of the uterus, part of which builds up during the secretory phase of the menstrual cycle and then sheds with menses o Myometrium - smooth muscle layer of uterus that allows for uterine contractions during labor and expulsion of menstrual blood o Perimetrium - outer epithelial layer of uterine wall External anatomy o Mons pubis - mound of fatty tissue located at the front of the vulva o Vulva - collective term for the external female genitalia o Labia majora - hair-covered folds of skin located behind the mons pubis o Labia minoa - thin, pigmented, hairless flaps of skin located medial and deep to the labia majora o Clitoris - (also, glans clitoris) nerve-rich area of the vulva that contributes to sexual sensation during intercourse

1. Identify and describe the gross anatomy of the mammary glands

o Lactiferous Ducts - ducts that connect the mammary glands to the nipple and allow for the transport of milk o Nipple - projection in which mammary ducts terminate o Lobules - contains clusters of alveoli o Lactiferous sinus - area of milk collection between alveoli and lactiferous duct o Areola - highly pigmented, circular area surrounding the raised nipple and containing areolar glands that secrete fluid important for lubrication during suckling

describe oogenesis and list its steps

• Produces haploid gamete via meiosis • Begins before birth • Steps: o Oogonia (2n) undergoes mitosis to become primary oocyte o Primary oocyte starts meiosis I and becomes stuck in prophase I o Stuck here until puberty o Meiosis I is completed on the day of ovulation • Secondary oocyte - large daughter cell • First polar body - smaller, disintegrates o Secondary oocyte proceeds to metaphase II and stops • Will die if not fertilized • If fertilized completes meisos II and casts off a second polar body

2. Describe the pathway of the ovum from the ovary to the uterus.

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list the steps in the hormonal cycle

1- Decreases in estrogen and progesterone cause the hypothalamus to release GnRH 2- GnRH causes anterior pituitary to release: o FSH • Targets primordial follicle to resume meiosis I • Developing follicle releses estrogen (uterine prolifertation) o LH • Surge causes ovulation (positive feedback of estrogen here triggers LH release) 3- Corpus luteum secretes progesterone and estrogen atht inhibit hypothalamus via negative feedback o If fertilization CL lives o If no fertilization CL dies

5. Describe the ovarian cycle and relate the events of the ovarian cycle to oogenesis

1- FOLLICULAR PHASE - cycle extends from the beginning of menstruation until ovulation -that is, from day 1 to day 14 in an average cycle - The portion from the end of menstruation until ovulation is also called the preovulatory phase - The follicular phase is the most variable part of the cycle, so RARELY reliably to predict the date of ovulation. DURING FOLLICULAR PHASE..... FSH stimulates continued growth of all follicles in the cohort, but of the dominant follicle above all. FSH stimulates the granulosa cells of the antral follicles to secrete estradiol. In response to estradiol, the dominant follicle up-regulates its receptors for FSH, LH, and estradiol itself, thereby becoming increasingly sensitive to these hormones. At the same time, estradiol inhibits the secretion of gonadotropin-releasing hormone (GnRH) by the hypothalamus. The anterior pituitary gland secretes less and less FSH, but an increasing amount of LH. Most antral follicles suffer from the reduced FSH level and degenerate (undergo atresia). The dominant follicle, however, has the richest blood supply and the greatest density of FSH receptors, so it becomes the mature, preovulatory follicle. The ovary, at this stage, also exhibits follicles in many other stages, belonging to other cohorts trailing behind the lead cohort like freshmen to juniors trailing behind the senior class. 2- OVULATION Ovulation is the rupture of the mature follicle and the release of its egg and attendant cells, typically around day 14. Dramatic changes over the preceding day signify its imminence. Estradiol stimulates a surge of LH and a lesser spike in FSH secretion by the pituitary . LH induces several momentous events. The primary oocyte completes meiosis I, producing a haploid secondary oocyte and the first polar body. Follicular fluid builds rapidly; the follicle swells to as much as 25 or 30 mm in diameter and contains up to 7 mL of fluid. Its size is astounding, considering that the entire ovary is only 10 mm thick. The preovulatory follicle bulges from the ovary like a blister. Macrophages and leukocytes are attracted to the area and secrete enzymes that weaken the follicular wall and adjacent ovarian tissue. A nipplelike stigma appears on the ovarian surface over the follicle. With mounting internal pressure and a weakening wall, the mature follicle approaches rupture.Meanwhile, the uterine tube prepares to catch the oocyte when it emerges. It swells with edema; its fimbriae envelop and caress the ovary in synchrony with the woman's heartbeat; and its cilia create a gentle current in the nearby peritoneal fluid. Ovulation itself takes only 2 or 3 min. The stigma seeps follicular fluid for 1 or 2 min., and then the follicle bursts. The remaining fluid oozes out, carrying the oocyte and cumulus oophorus. These are normally swept up by the ciliary current and taken into the uterine tube, although many oocytes fall into the pelvic cavity and die. 3- LUTEAL PHASE Days 15 to 28, from just after ovulation to the onset of menstruation, are called the luteal (postovulatory) phase. Assuming pregnancy does not occur, the major events of this phase are as follows. LOOK AT SCREENSHOTS TABLE WITH EVERYTHING

FEMALE REPRODUCTIVE SYSTEM

7 QUESTIONS 2PTS EACH

6. Describe the events of the uterine cycle.

ALSO CALLED MENSTRUAL CYCLE 1- PROLIFERATIVE PHASE The functional layer of endometrial tissue lost in the last menstruation is rebuilt during the proliferative phase. At the end of menstruation, around day 5, the endometrium is about 0.5 mm thick and consists only of the basal layer. But as a new cohort of follicles develops, they secrete more and more estrogen. Estrogen stimulates mitosis in the basal layer and the prolific regrowth of blood vessels, thus regenerating the functional layer . By day 14, the endometrium is 2 to 3 mm thick. Estrogen also stimulates endometrial cells to produce progesterone receptors, priming them for the progesterone-dominated secretory phase to follow. 2- SECRETORY PHASE The endometrium thickens still more during the secretory phase, but as a result of secretion and fluid accumulation rather than mitosis. This phase extends from day 15 (after ovulation) to day 26 of a typical cycle. After ovulation, the corpus luteum secretes mainly progesterone. This hormone stimulates the endometrial glands to secrete glycogen. The glands grow wider, longer, and more coiled, and the lamina propria swells with tissue fluid . By the end of this phase, the endometrium is 5 to 6 mm thick—a soft, wet, nutritious bed available for embryonic development in the event of pregnancy. 3- PREMENSTRUAL PHASE The last 2 days or so of the cycle are the premenstrual phase, a period of endometrial degeneration. As we have already seen, when there is no pregnancy, the corpus luteum atrophies and the progesterone level falls sharply. The drop in progesterone triggers spasmodic contractions of the spiral arteries of the endometrium, causing endometrial ischemia (interrupted blood flow). The premenstrual phase is therefore also called the ischemic phase. Ischemia brings on tissue necrosis (and menstrual cramps). As the endometrial glands, stroma, and blood vessels degenerate, pools of blood accumulate in the functional layer. Necrotic endometrium falls away from the uterine wall, mixes with blood and serous fluid in the lumen, and forms the menstrual fluid 4- MENSTRUAL PHASE When enough menstrual fluid accumulates in the uterus, it begins to be discharged from the vagina for a period called the menstrual phase (menses). The first day of discharge marks day 1 of a new cycle. The average woman expels about 40 mL of blood and 35 mL of serous fluid over a 5-day period. Menstrual fluid contains fibrinolysin, so it does not clot. The vaginal discharge of clotted blood may indicate uterine pathology rather than normal menstruation. LOOK AT SCREENSHOT

3. describe folliculogenesis and list its stages

As the egg undergoes oogenesis the follicle undergoes folliculogenesis. STAGES: Primordial follicles - primary oocyte + squamous follicular cells and basement membrane; diploid Primary follicle - larger, secondary oocyte + granulosa cells Secondary follicle - >=2 layers of granulosa cells; zona pellucida (glycoprotein gel) Tertiary follicle - granulosa cells secreting fluid and forming antrum Mature follicle - large, swells Corpus luteum - post ovulation, the "popped" follicle LOOK AT SCREENSHOT

describe estrogen

At puberty estrogen causes the pelvis to widen, and targets the deposition of fat to the breasts, hips, and thighs. During the normal monthly cycle estrogen may contribute to libido to some extent, but that is thought to be more from the production of testosterone from the theca cells. Further targets during the monthly cycle for estrogen include the endometrium of the uterus to grow and the hypothalamus to stimulate for GnRH release to cause LH release for ovulation to occur. Estrogen also makes cervical mucus thin, watery, and alkaline. This makes for good swimming conditions for sperm. When mucus is thin, it will look like fern leaves if placed on a glass slide. We will consider the effects of estrogen on the breasts and uterus again when we discuss pregnancy and the changes associated with that.

Both genders share fundamental anatomical structures:____________, ___________, and _________.

Both genders share fundamental anatomical structures: - copulatory organ - gonads - gametes.