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APHY 201 Exam 5e
Ch. 20 - The Female Reproductive System
| Question | Answer |
|---|---|
| What are the primary topics covered under the female reproductive system? | The primary topics include reproductive anatomy, puberty and menopause, oogenesis, the sexual cycle, female sexual response, pregnancy and childbirth, and lactation. |
| What is the first main purpose of the female reproductive system? | Its first purpose is to produce and deliver gametes. |
| What is the second main purpose of the female reproductive system? | Its second purpose is to provide nutrition and room for fetal development. |
| What are the final two purposes of the female reproductive system? | The final purposes are to give birth and to nourish the infant. |
| Are male and female embryos physically different early in development? | No, male and female embryos are indistinguishable for the first 8 to 10 weeks of development. |
| What causes a fetus to develop female anatomy? | A female develops due to the absence of hormones, specifically the absence of testosterone and müllerian-inhibiting factor. |
| What happens to the male mesonephric duct in a developing female? | The absence of male hormones causes the degeneration of the male mesonephric duct. |
| Which gender is considered the developmental "default"? | The female is considered the "default" gender. |
| What does the phallus develop into in a female? | The phallus becomes the clitoris. |
| What do the urogenital folds and labioscrotal folds become in a female? | The urogenital folds develop into the labia minora, and the labioscrotal folds develop into the labia majora. |
| What structures does the paramesonephric duct develop into? | The paramesonephric duct develops into the uterine tubes, uterus, and vagina. |
| What are the two primary functions of the ovaries? | The ovaries produce eggs and female hormones. |
| What is the shape and size of an ovary? | It is an almond-shaped organ that measures 3 cm by 1.5 cm by 1 cm. |
| What type of capsule covers the ovary? | Like the testes, the ovary is covered by a tunica albuginea capsule. |
| What do the cortex and medulla of the ovary contain? | The cortex produces gametes, and the medulla contains blood vessels. |
| Where does each egg develop before it is released? | Each egg develops in its own fluid-filled follicle. |
| What is the process of releasing an egg called? | The egg is released by ovulation, which is the bursting of the follicle. |
| What ligament attaches the ovary to the uterus? | The ovary is attached to the uterus by the ovarian ligament. |
| What ligament attaches the ovary to the pelvic wall and what does it contain? | The suspensory ligament attaches it to the pelvic wall and contains the ovarian artery, vein, and nerves. |
| What structure anchors the ovary to the broad ligament? | The ovary is anchored to the broad ligament by the mesovarium. |
| What structures make up the female internal genitalia? | The internal genitalia consist of a duct system that includes the uterine tubes, uterus, and vagina. |
| What structures make up the female external genitalia? | The external genitalia include the clitoris, labia minora, and labia majora. |
| Where are the external genitalia located? | The external genitalia occupy the perineum. |
| What is the function of the accessory glands beneath the skin? | The accessory glands beneath the skin provide lubrication. |
| What is the length and structure of a uterine tube? | It is a 10 cm long, muscular tube lined with ciliated cells. |
| What is the narrow portion of the uterine tube near the uterus called? | The portion near the uterus forms a narrow isthmus. |
| What is the middle portion of the uterine tube called? | The middle portion is called the body, or ampulla. |
| What does the distal end of the uterine tube flare into? | It flares distally into the infundibulum, which has fimbriae. |
| What ligament encloses the uterine tubes? | The uterine tubes are enclosed in the superior margin of the broad ligament, known as the mesosalpinx. |
| How is the physical appearance and position of the uterus described? | It is a thick-walled, pear-shaped muscular chamber that opens into the vagina and is tilted forward over the urinary bladder. |
| What openings does the uterus have? | It contains the internal and external os of the cervical canal, as well as openings into the uterine tubes in its two upper corners. |
| What is the domed portion of the uterus called? | The domed fundus sits above the body of the organ. |
| What is the external serosa layer of the uterine wall called? | The external serosa layer is called the perimetrium. |
| What is the middle muscular layer of the uterine wall called and how thick is it? | The middle muscular layer is the myometrium, which is 1 cm thick in a nonpregnant uterus. |
| What does the myometrium do? | The myometrium consists of smooth muscle running in all directions and produces labor contractions to expel the fetus during delivery. |
| What is the endometrium composed of? | The endometrium consists of a simple columnar epithelium plus a thick layer of compound tubular glands. |
| What is the stratum functionalis? | The stratum functionalis is the superficial two-thirds of the endometrium that is shed with each menstrual period. |
| What is the stratum basalis? | The stratum basalis is the deeper layer of the endometrium that regenerates a new stratum functionalis with each menstrual cycle. |
| What triggers menstrual flow? | Hormonal changes cause spiral artery vasoconstriction and the necrosis of the stratum functionalis, which leads to menstrual flow. |
| What are the dimensions and physical properties of the vagina? | The vagina is an 8 to 10 cm long, distensible muscular tube. |
| What are the three main functions of the vagina? | It allows for the discharge of menstrual fluid, the receipt of semen, and the birth of a baby. |
| What are the three tissue layers of the vagina? | The layers are the outer adventitia, the middle muscularis, and the inner mucosa. |
| How does the vaginal epithelium change from childhood to puberty? | In a child, the epithelium is simple cuboidal, but the estrogens of puberty transform it into stratified squamous epithelium through metaplasia. |
| Why does the vagina have an acidic pH? | Bacteria ferment the epithelial cells' glycogen into lactic acid, which produces an acidic vaginal pH. |
| How is the vagina positioned relative to other pelvic organs? | It is tilted posteriorly between the rectum and the urethra, with the urethra embedded in its anterior wall. |
| What is the hymen and how is it usually ruptured? | The hymen is a fold of vaginal mucosa that is generally ruptured by the first act of intercourse, if not previously ruptured by tampons, medical examinations, or strenuous exercise. |
| What does the term "vulva" or "pudendum" refer to? | It is the collective term for the female external genitalia. |
| What is the mons pubis? | The mons pubis is a mound of fat over the pubic symphysis. |
| What are the labia majora? | The labia majora are thick folds of skin that contain pubic hair. |
| What are the labia minora and what do they form? | The labia minora are more medial, thin, hairless folds that form the vestibule containing the urethral and vaginal openings, as well as a hoodlike prepuce over the clitoris. |
| What is the clitoris? | The clitoris is an erectile, sensory organ that is homologous to the glans penis of the male. |
| What are the vestibular bulbs? | The vestibular bulbs are erectile tissue located around the vagina. |
| What glands provide lubrication for the vestibule? | Paraurethral and greater and lesser vestibular glands, including Bartholin’s glands, open into the vestibule for lubrication. |
| What is the anatomical structure of the breasts? | They are a mound of tissue overlying the anterior rib cage, featuring a conical body with a nipple at its apex. |
| What does the axillary tail of the breast contain? | The axillary tail in the armpit contains many lymphatic vessels, which are an important route of metastasis for breast cancer. |
| What happens to the areola during pregnancy? | Melanocytes darken the areola during pregnancy. |
| How does the nipple respond to cold, touch, and arousal? | Smooth muscle contracts, wrinkling the skin and erecting the nipple in response to these stimuli. |
| What attaches the breast to the skin and muscle? | Suspensory ligaments attach it to the skin and muscle. |
| What is the composition of a nonlactating breast? | If nonlactating, it contains little glandular tissue and consists mainly of a system of branching ducts and adipose tissue. |
| How common is breast cancer in American women? | It affects 1 out of every 8 or 9 American women and is a leading cause of female mortality. |
| Where do breast tumors typically begin? | Tumors begin with cells from the mammary ducts. |
| What are the physical symptoms of breast cancer? | Symptoms may include a palpable lump, skin puckering (peau d'orange), skin texture changes, and drainage from the nipple. |
| Is most breast cancer hereditary? | Most breast cancer is nonhereditary, and 75% of cases are stimulated by estrogen. |
| What are the risk factors for breast cancer? | Risk factors include aging, ionizing radiation, carcinogenic chemicals, alcohol, smoking, and fat intake, though 70% of patients lack risk factors. |
| What are the primary screening and treatment options for breast cancer? | Detection involves breast self-examination and mammograms, while treatments include lumpectomy, simple mastectomy, or radical mastectomy. |
| At what age does puberty typically begin for most girls in the U.S.? | It begins at age 8 to 10 for most girls. |
| What hormone triggers puberty? | Puberty is triggered by rising levels of GnRH, which stimulate the anterior lobe of the pituitary to produce FSH and LH. |
| What effect does FSH have during puberty? | FSH stimulates follicles to secrete estrogen and progesterone. |
| What does estrogen do during puberty? | Estrogen causes sex organ maturation and an increase in the height and width of the pelvis. |
| What is thelarche? | Thelarche is the development of the breasts. |
| What is pubarche? | Pubarche is the growth of pubic and axillary hair, as well as apocrine and sebaceous glands. |
| What is menarche and what body fat percentage does it require? | Menarche is the first menstrual period, typically at age 12, and it requires at least 17% body fat in a teenager and 22% in an adult. |
| What is the climacteric? | The climacteric is a midlife change in hormone secretion that is accompanied by menopause. |
| At what age does menopause usually occur? | Menopause occurs between the ages of 45 and 55. |
| What causes the decline in estrogen and progesterone during menopause? | An age-related depletion of follicles results in less secretion of these hormones. |
| What physical changes are associated with menopause? | Changes include the atrophy of the uterus, vagina, and breasts, thinning skin, declining bone mass, increased risk of cardiovascular disease, and hot flashes. |
| What is Hormone Replacement Therapy (HRT)? | HRT is a low-dose estrogen and progesterone therapy that carries cancer risks for reproductive organs. |
| What is the difference between the reproductive cycle and the sexual cycle? | The reproductive cycle covers events occurring between fertilization and birth, while the sexual cycle involves events recurring every month when pregnancy does not occur. |
| What are the two components of the sexual cycle? | The sexual cycle consists of the ovarian cycle (events in the ovaries) and the menstrual cycle (parallel changes in the uterus). |
| How many eggs does oogenesis produce each month? | Oogenesis is a monthly event that produces 1 haploid egg by meiosis. |
| How many oogonia are produced by the fifth month of gestation? | Female germ cells differentiate into oogonia and multiply to 6 to 7 million by the fifth month of gestation. |
| How many primary oocytes remain by puberty? | Following atresia through childhood, only about 200,000 oocytes remain by puberty. |
| How many oocytes will a woman typically ovulate in her lifetime? | A woman will only ovulate about 480 oocytes in a typical reproductive lifetime, while the rest degenerate. |
| What does FSH stimulate the primary oocyte to become? | FSH stimulates the completion of meiosis I, producing a secondary oocyte and a 1st polar body. |
| What happens if the secondary oocyte is not fertilized? | If not fertilized, it never finishes meiosis II and is menstruated as a secondary oocyte. |
| What happens if the secondary oocyte is fertilized? | After fertilization, it finishes meiosis II to become an ovum and releases a 2nd polar body. |
| What is folliculogenesis? | Folliculogenesis is the development of the follicles around the egg that undergoes oogenesis. |
| What is a primordial follicle? | A primordial follicle consists of a primary oocyte in early meiosis surrounded by a single layer of squamous follicular cells, making up 90% to 95% of an adult ovary. |
| How long do primordial follicles wait before developing further? | They wait 13 to 50 years before they develop further, starting a 290-day path to maturity. |
| What characterizes a primary follicle? | Appearing about 140 days into the cycle, a primary follicle contains a larger primary oocyte and a surrounding layer of cuboidal follicular cells. |
| What characterizes a secondary follicle? | Appearing about 170 days into the cycle, oocytes are larger, follicular cells are in two or more layers (granulosa cells), and a zona pellucida and theca folliculi form. |
| What is the function of the theca interna? | The theca interna is an inner cellular layer that produces androgens, which granulosa cells convert to estradiol. |
| What marks the appearance of a tertiary follicle? | About 60 days before ovulation, granulosa cells secrete follicular fluid into small pools that merge to form a single antrum. |
| What is the cumulus oophorus? | It is a mound of granulosa cells on one side of the antrum that covers the oocyte and secures it to the follicular wall. |
| How does a dominant mature follicle survive while its rivals degenerate? | About 20 days before ovulation, the dominant follicle captures and holds FSH (potentially through receptor upregulation), allowing it to continue developing while rivals die as FSH levels fall. |
| What type of oocyte do primordial, primary, secondary, and tertiary follicles contain? | They all contain a primary oocyte. |
| What type of oocyte might a preovulatory (graafian) follicle contain? | Preovulatory follicles may contain either a primary or secondary oocyte. |
| What are the main topics covered under the female reproductive system? | The main topics include reproductive anatomy, puberty and menopause, oogenesis, the sexual cycle, female sexual response, pregnancy and childbirth, and lactation. |
| How long does the sexual cycle typically last? | The sexual cycle averages 28 days, but it varies from 20 to 45 days. |
| What role does the hypothalamus play in the sexual cycle? | Hormones of the hypothalamus regulate the pituitary gland. |
| What role do pituitary hormones play in the sexual cycle? | Pituitary hormones regulate the ovaries. |
| How do the ovaries influence the uterus? | The ovaries secrete hormones that regulate the uterus. |
| What is the basic hierarchy of hormonal control in the female reproductive system? | The hierarchy of control flows from the hypothalamus to the pituitary, then to the ovaries, and finally to the uterus. |
| How do the ovaries regulate the upper levels of the hormonal hierarchy? | The ovaries exert feedback control over the hypothalamus and the pituitary gland. |
| What two major events are included in the sexual cycle? | The sexual cycle includes the events of both the ovarian and menstrual cycles. |
| What phase begins the sexual cycle and how long does it last? | The cycle begins with a 2-week follicular phase. |
| When does menstruation occur during the sexual cycle? | Menstruation occurs during the first 3 to 5 days of the cycle. |
| What happens in the uterus and ovaries after menstruation? | The uterus replaces lost tissue by mitosis, and a cohort of follicles grows in the ovaries. |
| When does ovulation typically occur? | Ovulation occurs around day 14 of the cycle. |
| What happens to the remainder of the follicle after ovulation? | The remainder of the follicle becomes the corpus luteum. |
| What phase makes up the next two weeks of the cycle? | The next 2 weeks consist of the luteal phase. |
| What is the function of the corpus luteum during the luteal phase? | The corpus luteum stimulates endometrial secretion and thickening. |
| What happens to the endometrium if pregnancy does not occur? | If pregnancy does not occur, the endometrium breaks down in the last 2 days of the cycle. |
| How does the cycle conclude if there is no pregnancy? | Menstruation begins, and the cycle starts over. |
| What are the three principal steps of the ovarian cycle? | The three principal steps are the follicular phase, ovulation, and the luteal phase. |
| What does the ovarian cycle reflect? | This cycle reflects what happens in the ovaries and their relationship to the hypothalamus and pituitary. |
| When does the follicular phase occur? | The follicular phase extends from the beginning of menstruation until ovulation, typically Days 1 through 14. |
| What is the preovulatory phase? | The preovulatory phase is the period from the end of menstruation until ovulation. |
| Why is it difficult to predict the date of ovulation? | It is difficult because the follicular phase is the most variable part of the cycle. |
| What does Follicle-Stimulating Hormone (FSH) do during the follicular phase? | FSH stimulates follicles to grow and secrete estradiol. |
| How does the dominant follicle respond to hormones as it grows? | The dominant follicle becomes increasingly sensitive to FSH, LH, and estradiol. |
| Why does the dominant follicle become the preovulatory follicle? | It becomes the preovulatory follicle because it has a rich blood supply and a large number of FSH receptors. |
| What happens to the other antral follicles? | The other antral follicles degenerate in a process called atresia. |
| Are there other follicles in the ovary besides the active cohort? | Yes, the ovary also contains follicles at earlier stages for maturation in future cycles. |
| What defines the process of ovulation? | Ovulation is the rupture of the mature follicle and the release of its egg and attendant cells. |
| What hormone surge causes ovulation around day 14? | Ovulation is typically due to a surge in luteinizing hormone (LH). |
| What stimulates the spike in LH? | Rising estradiol levels from the growing follicle's granulosa cells stimulate a spike of LH and a lesser spike of FSH by the anterior pituitary. |
| What does LH induce the primary oocyte to do? | LH induces the primary oocyte to complete meiosis I, producing a secondary oocyte and a first polar body. |
| What physical changes happen to the follicle right before ovulation? | Follicular fluid builds rapidly, causing the follicle to swell so it resembles a blister on the ovary. |
| How is the follicle wall weakened before ovulation? | Macrophages and leukocytes secrete enzymes that weaken the follicle wall. |
| What visible sign appears on the surface of the follicle prior to bursting? | A nipple-like stigma appears on the surface. |
| How long does the actual event of ovulation take? | Ovulation takes only 2 to 3 minutes. |
| What occurs during the 1 to 2 minutes before the follicle bursts? | The stigma seeps follicular fluid. |
| What happens when the follicle finally bursts? | The follicle bursts and the remaining fluid oozes out, carrying the secondary oocyte and cumulus oophorus. |
| How is the oocyte captured by the uterine tube? | It is normally swept up by a ciliary current and conveyed into the uterine tube. |
| How does the uterine tube prepare to catch the oocyte? | The uterine tube swells with edema, and its fimbriae envelop and caress the ovary in synchrony with the woman's heartbeat. |
| What creates the current in the peritoneal fluid to help catch the egg? | Cilia create a gentle current in the nearby peritoneal fluid. |
| How does the maturing follicle influence the brain to trigger ovulation? | The maturing follicle secretes estradiol, which stimulates the hypothalamus to release GnRH and the anterior pituitary to secrete LH and FSH. |
| Why might couples want to track the signs of ovulation? | Couples may wish to know when ovulation occurs either to attempt to conceive a child or to avoid pregnancy. |
| How does cervical mucus change during ovulation? | The cervical mucus becomes thinner and more stretchy. |
| How does resting body temperature change during ovulation? | Resting body temperature rises 0.4° to 0.6°F. |
| What is the best way to measure basal body temperature for ovulation tracking? | It is best measured first thing in the morning before getting up, and recorded for several days to see the difference. |
| What is mittelschmerz? | Mittelschmerz refers to twinges of pain at the time of ovulation. |
| When is the best time for conception? | The best time for conception is within 24 hours after the cervical mucus changes and the basal temperature rises. |
| When does the luteal or postovulatory phase occur? | It occurs from day 15 to day 28, starting just after ovulation and ending at the onset of menstruation. |
| What happens to the ruptured follicle immediately after ovulation? | When the follicle ruptures, it collapses and bleeds into the antrum, and the clotted blood is slowly absorbed. |
| What cells multiply to fill the antrum of the collapsed follicle? | Granulosa and theca interna cells multiply and fill the antrum. |
| What structure does the ovulated follicle transform into? | The ovulated follicle becomes the corpus luteum. |
| Why is the corpus luteum named as such? | It is named for the yellow lipid that accumulates in the theca interna cells, which are now called lutein cells. |
| What hormone regulates the transformation into the corpus luteum? | The transformation is regulated by Luteinizing Hormone (LH). |
| What does LH stimulate the corpus luteum to do? | LH stimulates the corpus luteum to grow and secrete rising levels of estradiol and progesterone. |
| What is the most important aspect of the luteal phase regarding hormone levels? | A 10-fold increase in progesterone is the most important aspect of the luteal phase. |
| What is the crucial role of progesterone during the luteal phase? | Progesterone plays a crucial role in preparing the uterus for the possibility of pregnancy and prevents menstruation from occurring. |
| What happens to LH and FSH secretion over the rest of the cycle? | LH and FSH secretion declines over the rest of the cycle. |
| What causes the negative feedback effect on the hypothalamus and anterior pituitary? | High levels of estradiol and progesterone, along with inhibin from the corpus luteum, cause this negative feedback. |
| What happens to the corpus luteum if pregnancy does not occur? | The corpus luteum begins the process of involution, or shrinkage, around day 22. |
| What does the corpus luteum become once involution is complete by day 26? | It becomes a small scar called the corpus albicans. |
| Why do estrogen, progesterone, and inhibin levels eventually fall? | They fall because the involuting corpus luteum is no longer producing them. |
| What happens in the uterus when progesterone levels fall? | Without progesterone, menstruation in the uterus begins. |
| What allows a new cohort of follicles to start ripening for a new cycle? | Negative feedback on the hypothalamus and anterior pituitary ceases, allowing GnRH and FSH levels to rise again. |
| How frequently does ovulation occur in an ovary? | Ovulation occurs in one ovary per cycle, with the two ovaries usually alternating from month to month. |
| When did an ovulated oocyte actually begin its development process? | The ovulated oocyte began ripening 290 days earlier and began its initial development before birth. |
| What constitutes the menstrual cycle? | The menstrual cycle consists of a buildup of endometrium in the uterus during most of the sexual cycle, followed by its breakdown and vaginal discharge. |
| What are the four phases of the menstrual cycle? | The cycle is divided into the proliferative phase, the secretory phase, the premenstrual phase, and the menstrual phase. |
| What event marks day 1 of the sexual cycle? | The first day of noticeable vaginal discharge is defined as day 1 of the sexual cycle. |
| What is the average duration of the menstrual phase? | The menstrual phase averages 5 days. |
| What happens during the proliferative phase? | The proliferative phase involves the rebuilding of the functional layer, or stratum functionalis, of the endometrium that was lost in the last menstruation. |
| How thick is the endometrium at day 5 of menstruation? | At day 5, the endometrium is about 0.5 mm thick and consists only of the basal layer, or stratum basalis. |
| What hormone stimulates the rebuilding of the endometrium? | Estrogen from developing follicles stimulates mitosis in the basal layer and the regrowth of blood vessels to regenerate the functional layer. |
| How thick is the endometrium by day 14? | By day 14, the endometrium is 2 to 3 mm thick. |
| What other effect does estrogen have on endometrial cells? | Estrogen also stimulates endometrial cells to produce progesterone receptors. |
| What happens during the secretory phase? | The endometrium thickens more in response to progesterone from the corpus luteum, occurring from day 15 to day 26. |
| What causes the thickening of the endometrium during the secretory phase? | Thickening is due to secretion and fluid accumulation rather than mitosis. |
| What do the endometrial glands secrete during the secretory phase? | The endometrial glands secrete glycogen, and they grow wider, longer, and more coiled. |
| How thick does the endometrium become during the secretory phase? | The endometrium reaches 5 to 6 mm thick, becoming a soft, wet, nutritious bed available for embryonic development. |
| What characterizes the premenstrual or ischemic phase? | It is a period of endometrial degeneration during the last 2 days of the cycle. |
| What triggers the spasmodic contractions of spiral arteries? | The atrophy of the corpus luteum and falling progesterone levels trigger these contractions. |
| What does endometrial ischemia cause? | It causes interrupted blood flow, bringing about tissue necrosis and menstrual cramps. |
| How is menstrual fluid produced? | Pools of blood accumulate in the functional layer, and the necrotic endometrium mixes with this blood and serous fluid. |
| What is the menstrual phase or menses? | It is the discharge of menstrual fluid from the vagina. |
| How much fluid does the average woman expel during menses? | The average woman expels about 40 mL of blood and 35 mL of serous fluid over a 5-day period. |
| Why doesn't menstrual fluid clot? | It contains fibrinolysin so it does not clot. |
| What is endometriosis? | Endometriosis is the growth of endometrial tissue outside of the uterus. |
| Where does endometrial tissue commonly grow in this condition? | The growth is often on the peritoneum of the pelvic cavity or on the surface of the ovary. |
| How prevalent is endometriosis? | It affects 6% to 10% of women. |
| What are the symptoms of endometriosis? | It causes pain and sometimes infertility. |
| What is a believed cause of endometriosis? | It is believed to result from retrograde menstruation, which is the backward flow of menstrual fluid that exits the uterine tube. |
| How long does an average gestation or pregnancy last? | Gestation lasts an average of 266 days from conception to childbirth. |
| How is the gestational calendar measured? | It is measured from the first day of the woman's last menstrual period (LMP). |
| How many days from the LMP is birth predicted to occur? | Birth is predicted to occur 280 days from the LMP. |
| How is the pregnancy timeline divided? | It is divided into 3 three-month intervals called trimesters. |
| What is the developmental term for a conceptus less than 2 weeks old? | It is called a blastocyst. |
| What is the developmental term for a conceptus from 3 to 8 weeks old? | It is called an embryo. |
| What is the developmental term from 9 weeks to birth? | It is called a fetus. |
| What is a newborn called up to 6 weeks of age? | It is called a neonate. |
| What does the blastocyst consist of? | The blastocyst consists of an inner cell mass (developing embryo) and an outer cell mass (trophoblast). |
| What is implantation? | Implantation is the attachment of the conceptus to the endometrium. |
| What makes up the placenta? | The placenta is made of both maternal and trophoblastic tissue. |
| How is the embryo attached to the placenta? | The embryo is attached to the placenta by the umbilical cord and floats in amniotic fluid. |
| What is Human Chorionic Gonadotropin (HCG) and when is it secreted? | HCG is a hormone secreted by the trophoblast within 9 days of conception. |
| How is HCG used in medical testing? | HCG in the urine is the basis of many home pregnancy tests. |
| What crucial function does HCG perform early in pregnancy? | It prevents the involution of the corpus luteum by stimulating it the way LH would, essentially allowing the embryo to guarantee its own survival. |
| How much do estrogen levels increase before birth? | Estrogens increase to 30 times their normal levels before birth. |
| What is the source of estrogens for the first 12 weeks of pregnancy? | The corpus luteum is the source for the first 12 weeks until the placenta takes over. |
| What physical effects do estrogens have on the mother? | They cause uterine, mammary duct, and breast enlargement. |
| Where is progesterone secreted from during pregnancy? | Progesterone is secreted by the corpus luteum and the placenta. |
| What role does progesterone play in sustaining pregnancy? | It suppresses the secretion of FSH and LH, prevents follicular development, prevents menstruation, thickens the endometrium, and stimulates the development of acini in breast tissue. |
| What is Human Chorionic Somatomammotropin (HCS)? | HCS is also called human placental lactogen and is secreted from the placenta in direct proportion to its size. |
| What metabolic effect does HCS have on the mother? | It decreases the mother's glucose usage and increases the release of fatty acids. |
| How does the thyroid gland change during pregnancy? | The thyroid gland increases 50% in size, raising the mother's basal metabolic rate (BMR). |
| How do the parathyroid glands adapt to pregnancy? | The parathyroid glands enlarge and stimulate osteoclasts to release additional calcium from the mother's bones. |
| What does increased aldosterone secretion cause during pregnancy? | Aldosterone secretion increases fluid retention and leads to an increase in the mother's blood volume. |
| What might cause morning sickness during early pregnancy? | Nausea may stem from reduced intestinal motility, or it could be an evolutionary adaptation to protect the fetus from toxins. |
| What causes constipation and heartburn during pregnancy? | These are caused by decreased intestinal motility and pressure on the stomach. |
| What is a healthy amount of weight gain during pregnancy? | A healthy weight gain is 24 lbs. |
| What does the placenta store prior to the 3rd trimester? | The placenta stores nutrients, as there is a high demand for protein, iron, calcium, and phosphates. |
| Why is supplemental vitamin K given during pregnancy? | It reduces the risk of neonatal hemorrhages in the brain during delivery. |
| Why is early supplemental folic acid important? | It prevents neurological disorders such as spina bifida and anencephaly. |
| How much does the mother's blood volume rise during pregnancy and why? | Blood volume rises 30% due to fluid retention and hemopoiesis. |
| How much blood does the placenta require per minute by full term? | It requires 625 mL of blood per minute. |
| What happens to the mother's cardiac output? | Cardiac output rises about 30% by 27 weeks, then falls to normal again for unknown reasons. |
| What can pressure on large pelvic blood vessels produce? | It can produce hemorrhoids and varicose veins. |
| How does the mother's respiratory ventilation change? | Minute respiratory ventilation increases about 50% to meet the demands of the fetus and the higher maternal metabolic rate, and to keep PCO2 lower than normal. |
| Why does the respiratory rate increase during pregnancy? | It increases due to the inability to breathe as deeply. |
| How much does the Glomerular Filtration Rate (GFR) increase? | GFR increases by 50%, enabling the woman to dispose of additional metabolic wastes. |
| What causes increased frequency of urination? | Bladder compression causes an increased frequency of urination. |
| What skin changes can occur during pregnancy? | Skin must grow, leading to stretch marks (striae); the linea alba may darken into the linea nigra; and a temporary blotchy darkening called chloasma or the "mask of pregnancy" may appear. |
| What is parturition? | Parturition is the process of giving birth by means of the contraction of the mother's uterine and abdominal muscles. |
| What are Braxton Hicks contractions? | Braxton Hicks contractions are weak contractions occurring throughout gestation, commonly known as false labor. |
| How do hormones influence uterine contractions? | Progesterone inhibits contractions to sustain pregnancy, while estrogen stimulates them. |
| What hormonal changes trigger labor nearing full term? | The posterior pituitary releases more oxytocin, and the uterus produces more receptors for it, directly stimulating myometrial contractions. |
| How do fetal hormones contribute to labor? | The fetus secretes cortisol which enhances estrogen secretion, and fetal oxytocin stimulates fetal membranes to secrete prostaglandins that enter the mom's circulation to synergize with oxytocin. |
| How frequently do labor contractions occur? | They begin 30 minutes apart and eventually occur every 1 to 3 minutes. |
| Why do contractions periodically relax? | They relax to increase blood flow to the placenta and fetus. |
| Where are contractions the strongest? | They are strongest in the fundus and body, pushing the fetus into the cervix. |
| What is the reflex cycle of labor contractions? | It is a self-amplifying positive feedback cycle of stretch and contraction where cervical stretching leads to oxytocin secretion, which causes uterine contraction and more cervical stretching. |
| What is the second reflex arc during labor? | The 2nd reflex arc travels from the uterus to the spinal cord to the abdominal skeletal muscles, producing contractions and the urge to push. |
| What causes the pain of labor? | Pain is caused by ischemia of the myometrium, and the stretching of the cervix, vagina, and perineum. |
| What happens during the Early Dilation Stage of labor? | The cervical canal widens through effacement (thinning) to reach 10 cm, accompanied by the rupture of fetal membranes and loss of amniotic fluid. |
| How long does the Late Dilation Stage take? | Dilation reaches 10 cm in 24 hours or less in a primipara (first baby), and in as little as a few minutes in a multipara. |
| What defines the Expulsion Stage of labor? | It is the time from the baby's head entering the vagina (crowning) until delivery. |
| How long does the Expulsion Stage last? | It may last up to 30-60 minutes in a primipara, or as little as 1 minute in a multipara. |
| What happens during the Placental Stage? | Uterine contractions continue, causing placental separation, which normally involves 350 mL of blood loss. |
| What are the expelled fetal membranes called? | The expelled membranes are called the afterbirth. |
| What is the puerperium? | The puerperium is the first 6 weeks after delivery when the mother's anatomy and physiology return to normal. |
| What is the shrinkage of the uterus called? | The shrinkage of the uterus is called involution, accomplished by autolysis by lysosomal enzymes. |
| What is the vaginal discharge after birth called? | The post-birth vaginal discharge is called lochia. |
| How does breastfeeding aid in postpartum recovery? | Breastfeeding promotes involution by suppressing estrogen secretion and stimulating oxytocin, which causes myometrial contractions. |
| What is lactation? | Lactation is the synthesis and ejection of milk from the mammary glands. |
| How do estrogen and progesterone affect mammary glands during pregnancy? | High estrogen levels cause ducts to grow and branch, while progesterone stimulates the budding and development of the acini at the ends of the ducts. |
| What is colostrum? | Colostrum is a fluid that forms in late pregnancy; it is similar to breast milk but thinner, contains 1/3 less fat, and provides nutrition and IgA protection for the first 1 to 3 days after birth. |
| What hormone promotes milk synthesis? | Synthesis is promoted by prolactin from the pituitary gland. |
| How do prolactin levels change after birth? | At birth, prolactin secretion drops to nonpregnant levels but jumps 20 times with each nursing to prepare for the next feeding. |
| What happens if continuous nursing stops? | Without continuous nursing, milk production stops in 1 week. |
| Why is it unlikely for women to become pregnant while nursing? | Only 5-10% of women become pregnant while nursing due to the inhibition of GnRH and reduced ovarian cycling. |
| How is milk ejection or let-down controlled? | It is controlled by a neuroendocrine reflex where the infant's suckling stimulates the release of oxytocin from the posterior pituitary, which then stimulates myoepithelial cells. |
| What do myoepithelial cells do? | Myoepithelial cells act like smooth muscle, squeezing milk into the duct within 30-60 seconds of suckling. |
| Why is cow's milk not a good substitute for human breast milk? | Cow's milk has 1/3 less lactose but 3 times as much protein, making it harder to digest and resulting in more nitrogenous waste. |
| What laxative effect does breast milk have? | Colostrum and breast milk help clear the infant's intestine of meconium, a green, bile-filled fecal material. |
| What is abruptio placentae? | It is the premature separation of the placenta from the uterine wall. |
| What is placenta previa? | It is a condition where the placenta blocks the birth canal, requiring a Cesarean section. |
| What is an ectopic pregnancy? | An ectopic pregnancy is the implantation of the conceptus anywhere other than the uterus, usually in the uterine tube. |
| What defines gestational diabetes? | It is an insulin insensitivity that develops during pregnancy, characterized by hyperglycemia, glycosuria, and the risk of a large baby leading to birth trauma. |
| What is pre-eclampsia? | Pre-eclampsia is the rapid onset of severe hypertension, edema, and proteinuria. |
| What can pre-eclampsia progress to? | It may progress to eclampsia, which involves seizures, vascular spasms, and can be potentially fatal. |
| What is the function of the aromatase enzyme? | The aromatase enzyme converts testosterone to estradiol in males and females. |
| (added) describe control of ovulation | Graafian follicle releases estrogen to stimulate hypothalamus to release GnRH to stimulate anterior pituitary to release LH to cause ovulation |
| (added) in what conditions is aromatase active | Aromatase is most active in tissues responsible for androgen-to-estrogen conversion. In females, it is highly active in ovarian granulosa cells. In males and postmenopausal women, it is primarily active in adipose (fat) tissue, muscle, brain, and bones |
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