Anatomy and Physiology [Repro] Flashcards
The suspensory ligament of the ovaries connects […] to […].
The suspensory ligament of the ovaries connects ovaries to lateral pelvic wall. It contains ovarian vessels. The ureter at risk of injury during ligation of ovarian vesels in oophorectomy.
The transverse cervical (cardinal) ligament connects […] to […].
The transverse cervical (cardinal) ligament connects cervix to side wall of pelvis. It contains uterine vessels. The ureter at risk of injury during ligation of uterine vesels in hysterectomy.
The round ligament of the uterus connects […] to […].
The round ligament of the uterus connects uterine fundus to labia majora. Derivative of the gubernaculum. Travels through inguinal canal.
[Round like the number of structures it carries]
The broad ligament connects […] to […].
The broad ligament connects uterus, fallopian tubes, and ovaries to pelvic side wall. Contains ovaries, fallopian tubes, and round ligaments of uterus. Composed of mesosalpinx, mesometrium, and mesovarium.
The ligament of the ovary connects […] to […].
The ligament of the ovary connects ovary to lateral uterus.
What is the pathway of sperm during ejaculation?
Seminiferous tubules
Epididymus
Vas deferens
Ejaculatory duct
Urethra
Penis
[SEVEN UP]
What is the autonomic innervation for erection, emission and ejaculation?
Erection - parasympathetic nervous system (pelvic nerve)
- NO → cGMP → sequestration, smooth muscle relaxation → vasodilation → proerectile
- NE → [Ca2+]in → smooth muscle contraction → vasoconstriction → antierectile
- Sildenafil, vardenafil inhibit cGMP breakdown
Emission - sympathetic (hypogastric nerve)
Ejaculation - visceral and somatic nerves (pudental nerve)
[Point and Shoot]
Source of androgens?
Testes - DHT and testosterone
Adrenal - androstenedione
Potency of androgens?
DHT > testosterone > androstenedione
What is the function of 5α-reductase and what is it inhibited by?
Enzyme that converts testosterone to DHT. It is inhibited by finasteride.
What is the function of aromatase (in men)?
Enzyme that converts testosterone and androstenedione to estrogens in adipose tissue and Sertoli cells.
What are some functions of testosterone?
- Differentiation of epididymis, vas deferens, seminal vesicles (internal genitalia except prostate)
- Growth (growth spurt, muscles, penis, seminal vesicles, sperm, RBCs
- Closing of epiphyseal growth plate (via oestrogen derived from testosterone)
- Deepening of voice
- Libido
What are the early and late functions of DHT?
Early - differentiation of penis, scrotum, prostate
Late - prostate growth, balding, sebacious gland activity (oily bald guy who can’t pee)
Sources of oestrogens?
Ovary - 17beta-estradiol
Placenta - estriol
Peripheral - via aromatization
Potency of oestrogens?
Estradiol > estrone > estriol
What changes occur to oestrogen levels in pregnancy?
50x increase in estradiol and estrone. 1000x increase in estriol (indicator of fetal well-being).
What are some functions of oestrogen?
- Development of breast and genitalia, female fat distribution
- Growth of follicle, endometrial proliferation, increased myometrial excitability
- Upregulation of estrogen, LH, and progesterone receptors
- Feedback inhibition of FSH and LH, then LH surge
- Stimulation of prolactin secretion (but blocks its action at the breast)
- Hepatic synthesis of transport proteins, SHBG; increased HDL, decreased LDL
What does pulsatile GnRH upregulate?
FSH and LH
What does desmolase respond to in the ovary and what does it do?
In response to LH, desmolase (in theca cells) begins the reactions converting XOL to androstenedione
(providing the substrate for aromatase in the granulosa cell).
What does aromatase respond to in the ovary and what does it?
In response to FSH, aromatase (in granulosa cells) converts androstenedione to oestrogen
Sources of progesterone?
Corpus luteum, placenta, adrenal cortex, testes
What does elevation of progesterone indicate?
Indicates ovulation
What are some functions of progesterone?
- Stimulation of endometrial glandular secretions and spiral artery development
- Maintenance of pregnancy
[progesterone is pro-gestation] - Decreases myometrial excitability, uterine smooth muscle relaxation (preventing contraction)
- Production of thick cervical mucus, which inhibitis sperm entry into the uterus
- Increases body temperature (seen after ovulation)
- Inhibition of gonadotropins (LH, FSH), deccreases oestrogen receptor expression
When is follicular growth the fastest in the menstrual cycle?
During the 2nd week of the proliferative phase
What does oestrogen do in the menstrual cycle?
Stimulates endometrial proliferation.
What does progesterone do in the menstrual cycle?
Maintains endometrium to support implantation (decreased progesterone leads to decreased fertility).
What are the phases of the menstrual cycle?
Proliferative (follicular) phase → (ovulation) → secretory (luteal) phase
The […] phase of the menstrual cycle can vary in length, but the […] phase is usually a constant […].
The follicular phase of the menstrual cycle can vary in length, but the luteal phase is usually a constant 14 days. Ovulation day + 14 days = menstruation.
What is the order of events in terms of blood hormones and the menstrual cycle?
Estrogen surge → LH surge → Ovulation → Progesterone (from corpus luteum) → Menstruation (via apoptosis of endometrial cells)
What causes ovulation?
Increased oestrogen, increased GnRH receptors on anterior pituitary. Oestrogen surge then stimulates LH release, which causes ovulation (rupture of follicle).
What are some features of ovulation?
- Increased temperature (progesterone induced)
- Mittelschmerz (blood from ruptured follicle causes peritoneal irritation that can mimic appendicitis)
- Ferning of cervical mucosa (formation of fernlike pattern in a specimen of crystallized cervical mucus secreted at midcycle)
What are some functions of spermatogonia (germ cells)?
Maintain germ pool and produce primary spermatocytes. Line seminiferous tubules.
What are some functions of Sertoli Cells (non-germ cells)?
- Secrete inhibin - inhibit FSH
- Secrete androgen-binding protein (ABP) - maintain levels of testosterone
- Form blood-testis barrier - isolate gametes from autoimmune attack
- Support and nourish developing spermatozoa; regulate spermatogenesis
- Produce anti-mullerian hormone
- Temperature sensitive - decreased sperm production and decreased inhibin with increased temperature
[Sertoli cells Support Sperm Synthesis]
Increased temp in varicocele, cryptorchidism
What are some functions of Leydig cells (endocrine cells)?
Secrete testosterone (unaffected by temperature). Located in the interstitium.
Spermatogenesis occurs in […] tubules and begins at […] with spermatogonia. Full development takes […].
Spermatogenesis occurs in seminiferous tubules and begins at puberty with spermatogonia. Full development takes 2 months.
In step 1 (replication) of spermatogenesis, a 2N, 2C […] which passes through the […] and replicates to become a 2N, 4C […].
In step 1 of spermatogenesis (replication) a 2N, 2C diploid spermatogonium which passes through the blood-testis barrier tight junction and replicates to become a 2N, 4C diploid primary spermatocyte.
In step 2 (meiosis I) of spermatogenesis, the […]N, […]C diploid primary spermatocyte becomes two […]N, […]C haploid secondary spermatocytes.
In step 2 (meiosis I) of spermatogenesis, the 2N, 4C diploid primary spermatocyte becomes two 1N, 2C haploid secondary spermatocytes.
In step 3 (meiosis II) of spermatogenesis, the two haploid secondary spermatocytes becomes four […]N, […]C haploid […].
In step 3 (meiosis II) of spermatogenesis, the two haploid secondary spermatocytes becomes four 1N, 1C haploid spermatids. These then develop into spermatozoa in spermiogenesis.
What hormones are involved in the regulation of spermatogenesis?
Hypothalamus → GnRH → anterior pituitary →
LH → stimulates testosterone release from Leydig cells
FSH → stimulates Sertoli cells to produce ABP and inhibin
Anterior pituiatry receives negative feedback from inhibin created by Sertoli cells.
Hypothalamus receives negative feedback from testosterone released into blood by Leydig cells.
Primary oocytes begin meiosis I during […] and are arrested in […] until just prior to […].
Primary oocytes begin meiosis I during foetal life and are arrested in prophase until just prior to ovulation.
[prophase until ovulation]
Secondary oocytes undergoing meiosis II are arrested in […] until […].
Secondary oocytes undergoing meiosis II are arrested in metaphase until fertilisation. If fertilization does not occur, the secondary oocyte degenerates.
[An egg MET a sperm]
The secondary oocyte will degenerate unless what occurs?
Fertilization.
In step 1 (replication) of oogenesis, a 2N, 2C […] replicates to become a 2N, 4C […].
In step 1 (replication) of oogenesis, a 2N, 2C diploid oogonium replicates to become a 2N, 4C diploid primary oocyte.
In step 2 (meiosis I) of oogenesis, a primary oocyte divides into a […]N, […]C haploid secondary oocyte and a […].
In step 2 (meiosis I) of oogenesis, a primary oocyte divides into a 1N, 2C haploid secondary oocyte and a polar body. The polar body can degenerate or give rise to 2 polar bodies. Meiosis I is arrested in Prophase I until ovulation.
In step 3 (meiosis II) of oogenesis, the haploid secondary oocyte divides into a […]N, […]C haploid […] and a […].
In step 3 (meiosis II) of oogenesis, the haploid secondary oocyte divides into a 1N, 1C haploid ovum and a polar body. Meisosis II is arrested in metaphase II until fertilization.
Fertilization most commonly occurs in […] within […] day(s) after ovulation.
Most commonly occurs in the upper end of fallopian tube (ampulla) within 1 day(s) after ovulation.
Implantation most commonly occurs in […] around day […] after fertilisation.
Implantation most commonly occurs in the wall of the uterus around day 6 after fertilisation.
What do you measure in a home pregnancy test, and how soon can you see it?
Trophoblasts secrete β-hCG, which is detectable in blood 1 week after conception and on home test in urine 2 weeks after conception.
What induces and maintains lactation after labor?
The drop in progesterone induces lactation. Suckling is required to maintain milk production,
since increased nerve stimulation → increased oxytocin and prolactin.
What is prolactin’s function postpartum?
Induces and maintains lactation and decreases reproductive function (suppresses GnRH).
What is oxytocin’s role postpartum?
Appears to help with milk letdown and promotes uterine contractions.
Source of hCG?
Syncytiotrophoblast of the placenta.
What are some functions of hCG?
- Maintains corpus luteum (and thus progesterone) for the 1st trimester by acting like LH (otherwise no luteal cell stimulation, and abortion results). In the 2nd and 3rd trimester, the placenta synthesizes its own estriol and progesterone and the corpus luteum degenerates.
- Used to detect pregnancy b/c it appears early in the urine.
- Elevated hCG in pathologic states (e.g., hydatidiform moles, choriocarcinoma, gestational trophoblastic tumors).
What is menopause and the average age of onset?
Decreased oestrogen production due to age-linked decline in number of ovarian follicles. Average age of onset is 51 yrs (earlier in smokers). Usually preceded by 4-5 years of abnormal cycles.
What are some hormonal changes seen in menopause?
Decreased: oestrogen
Increased:
(++) FSH
(+) LH (no surge)
(+) GnRH
(+) Androgens (causes hirsutism)
What are some features of menopause?
- *H**ot flashes, Hirsutism
- *A**trophy of the Vagina
- *O**steoporosis
- *C**oronary artery disease
- *S**leep disturbances
[Menopause causes HHAVOC]
What can early menopause indicate?
Premature ovarian failure (primary ovarian insufficiency)
