Term
| Which male cell is responsible for the release of antimullarian hormone which causes the female ducts to degenerate? |
|
Definition
|
|
Term
| Which male cell is reponsible for the release of testosterone? |
|
Definition
| Leydig cells ('cause testosterone gets you "Leyd") |
|
|
Term
| Why can't Leydig cells produce glucocortiods or mineralcurticoids like the cells of the adrenal gland? |
|
Definition
| they lack 21B-hydroxylase and 11B-hydroxylase, which shuts off all options for producing any glucocorticoids or mineral corticoids |
|
|
Term
| How are LH and ACTH similar in their activity? |
|
Definition
| They both stimulate the conversion of cholesterol into pregnenolone (a mutual pathway in both corticoids and androgens) |
|
|
Term
| Which enzyme (responsible for converstion of cholesterol into pregnenoline) do both LH and ACTH increase production of? |
|
Definition
|
|
Term
| Which organs possess 5A-reductase? |
|
Definition
| male accessory sex organs, converts testosterone into more biologically active form, DHT |
|
|
Term
| Testosterone has negative feedback inhibition on which two glands (substances)? |
|
Definition
| Hypothalamus (GnRH) and adenohypophysis (LH) |
|
|
Term
| Inhibin, the negative feedback regulator of FSH at the adenohypophysis, is secreted by which male cell type? |
|
Definition
| Sertoli cells (inhibin is release in response to FSH) |
|
|
Term
| Which male hormone is responsbile for spermatogenesis? |
|
Definition
| FSH (stimulates Sertoli cells) |
|
|
Term
| How is LH involved in spermatogenesis? |
|
Definition
| LH stimulates Leydig cells, which subsequently produce testosterone; testosterone reinforces the spermtogenic effects of FSH in the Sertoli cells via its paracrine activity |
|
|
Term
| How are the roles of testosterone and and DHT different in the development of male sex organs? |
|
Definition
Testosterone is responsible for development of wolffian ducts
DHT - external genitalia |
|
|
Term
| Which male hormone has a primary role in the growth spurt seen in adolescent males? |
|
Definition
|
|
Term
| Which male hormone has more activity for stimulating secretory activity of the epididymis, vas deferens, prostate, and seminal vesicles? |
|
Definition
|
|
Term
| Which male hormone makes you want to have crazy sex (increased libido)? |
|
Definition
|
|
Term
| What endocrine changes initiate puberty? |
|
Definition
| Pulsitile release of GnRH (from hypothalamus) which subsequently causes the pulsitile release of FSH and LH; GnRH receptors are also up-regulated at pituitary |
|
|
Term
| How do LH and FSH ratios vary throughout life? |
|
Definition
Prepuberty: FSH greater than LH
Adolescence: LH greater than FSH
Old age: FSH greater than LH |
|
|
Term
| Which female cells are responsible for producing testosterone? |
|
Definition
|
|
Term
| Which female cells convert testosterone into estradiol? |
|
Definition
|
|
Term
| What is meant by leuteinization? |
|
Definition
| transformation of the follicle into the corpus luteum after ovulation |
|
|
Term
| What are the four primary effects of LH and FSH on ovaries? |
|
Definition
1. steroidogenesis in ovarian follicle (androgens and estrogens) and corpus luteum (progesterone)
2. follicular development beyond the antral stage (maintains follicle to ovulation)
3. ovulation
4. leteinization |
|
|
Term
| What are the biphase properties of estrogen? |
|
Definition
low levels --> (-) of GnRH from pituitary
high levels --> positive feedback triggering LH surge necessary for ovulation |
|
|
Term
| What are some of the effects of progesterone? |
|
Definition
- negative feedback on LH/FSH during luteal phase
- maintains secretory activity of uterus during luteal phase
- maintains pregnancy
- raises uterine contractility threshold
- contributes to breast development |
|
|
Term
|
Definition
| sex determining factor (on Y chromosome); formerly called determining factor |
|
|
Term
|
Definition
| antimullerian hormone; causes regression of the mullerian ducts; AMH is released by Sertoli cells |
|
|
Term
|
Definition
| five-alpha reductase; converts testosterone into DHT at target tissues |
|
|
Term
| What is true of androgen receptors in regards to testosterone and DHT? |
|
Definition
| androgen receptors bind both, but have a greater affinity for DHT |
|
|
Term
| What components of FSH and LH have biologic activity? |
|
Definition
|
|
Term
| What cell releases inhibin and what are its effects? |
|
Definition
| granulosa cells, negative feedback on FSH |
|
|
Term
| Which hormone is most strongly assoc. w/ spermatogenesis? |
|
Definition
|
|
Term
| Which hormone is most strongly assoc. w/ steroidogenesis? |
|
Definition
|
|
Term
| What non-sexual organ/tissue converts androgens into estrogens? |
|
Definition
|
|
Term
| Why is finasteride given to male patients with BPH? |
|
Definition
| it is a 5a-reductase inhibitor; prevents the converstion of testosterone into DHT |
|
|
Term
| What are the four delta-four steroids exhibiting most biologic activity? |
|
Definition
progesterone
17-hydroxprogesterone
androstenedione
testosterone |
|
|
Term
| Which enzyme converts delta-3 steroids into delta-4 steroids? |
|
Definition
| 3B-hydroxysteroid dehydrogenase (delta-3-4-isomerase) |
|
|
Term
| How many carbons do androgens and estrogens have? |
|
Definition
androgens - 19
estrogens - 18 |
|
|
Term
| Which steroids have NO double bond in carbon-ring structures? |
|
Definition
|
|
Term
| What is significance of the 11th carbon position in steroids? |
|
Definition
| it gives steroids corticoid activity (cortisol) |
|
|
Term
| What is the significant of oxygen at the 18th carbon position? |
|
Definition
| gives steroid mineralcorticoid activity (aldosterone) |
|
|
Term
| How are 5a-reductase and aromatase similar, but different? |
|
Definition
both act on testosterone
5a-reductase --> DHT
aromatase --> estradiol |
|
|
Term
| What percentage of testosterone is bound by sex hormone-binding hormone (SHBH)? |
|
Definition
|
|
Term
| Which plasma protein is responsible for binding 55% of testosterone? |
|
Definition
|
|
Term
| What percentage of testosterone is free? |
|
Definition
| 2%, biologically active percentage of testosterone |
|
|
Term
| How can testosterone complicate urineanalysis in both SIADH and Addison disease? |
|
Definition
| testosterone is metabolized to a 17-ketosteroid by the liver, which is the same breakdown product of both glucocorticoids and mineralcorticoids |
|
|
Term
| A patient with an unknown 5a-reductase deficiency may present with what uncommon physical finding untul puberty? |
|
Definition
| ambiguus genitalia (Dr. Watson - penis at 12) |
|
|
Term
| What primordial tract is stimulated by testosterone? |
|
Definition
|
|
Term
| What is the major contraindication with testosterone therapy/supplementation? |
|
Definition
|
|
Term
The following characteristics are assoc. w/ what disorder:
47 XXY male
little hair
long arms
general female phenotype
hypogonadism of male external genitalia |
|
Definition
|
|
Term
| A patient presenting w/ comlete or incomplete testicular feminization, pseudohermaphrodism (Reifenstein's syndrome), and/or under virilized males, but w/out any enzyme deficiency may have what condition? |
|
Definition
| dysfunctional steroid receptors |
|
|
Term
| Elevated levels of p120, PCNA, inhibin-a and PSA are suggestive of what condition? |
|
Definition
|
|
Term
| How are TSH, primary hypothyroidism, prolactin, and erectile dysfunction related? |
|
Definition
primary hypothyroidism means elevated TSH levels
elevated TSH levels have cross over stimulation of prolactin
prolactin in male contributes to erectile dysfunction |
|
|
Term
| What are the general contraindications for Viagra (sildenafil citrate), Levitra, and Cialis? |
|
Definition
| recent MI, stroke, retinal pigmentosa, alpha-blockers |
|
|
Term
| What is the mechanism of action for viagra (sildenafil citrate), Levitra, and Cailis? |
|
Definition
| phosphodiesterase-5 inhibitors, sustains PDE-5 <-- necessary for maintaining erection |
|
|
Term
| What is the average time necessary for sperm maturation? |
|
Definition
|
|
Term
| What cells produce androgen binding protein? |
|
Definition
|
|
Term
| What is the relationship between interstitial cells (Leydig cells), LH, and steroidogenesis? |
|
Definition
| interstitial cells are stimulated by LH to produce testosterone, LH enhances production of SCC enzyme <-- rate-limiting step of steroidogenesis |
|
|
Term
| Sperm remain immobile until after what period of time of residence w/in the epididymis? |
|
Definition
|
|
Term
| What is the average life expectancy of sperm upon ejaculation? |
|
Definition
|
|
Term
| what aspect of the vagina capacitates sperm? |
|
Definition
|
|
Term
| What role do prostaglandins have in fertilization? |
|
Definition
| they stimulate spermatic mobility and retrograde vaginal contractility |
|
|
Term
| What substances secreted from the prostate facilitate the formation of the spermatic plug? |
|
Definition
| calcium citrate, phosphate, clotting enzymes, and profibrinolysin |
|
|
Term
| The SEVEN UP pneumonic for remembering the passage of sperm... |
|
Definition
Seminiferous tubules
Epididymis
Vas deferens
ejaculatory duct
Nothing
Urethra
Penis
|
|
|
Term
| What are the layers of the scrotal sac? (hint: Some Darn Englishman Called It The Testis) |
|
Definition
| skin, darto, external spermatic fascia, cremaster, internal spermatic fascia, tunica vaginalis, testis |
|
|
Term
|
Definition
| enzyme in acrosomal region of head of sperm necessary for penetration into the oocyte |
|
|
Term
| The hyaluronidase enzyme recognizes what? |
|
Definition
|
|
Term
| What is true of the mucal cervical plug during the menstrual cycle? |
|
Definition
estrogen dominated portions of cycle cervical plug is thin
progesterone dominated portions of cycle cervical plus is thick |
|
|
Term
| Administration of what substances can complete passage of testicle upon presentation of cryptorchidism? |
|
Definition
|
|
Term
| What is the level at which a man in considered to be infertile in regards to sperm count? |
|
Definition
| anything less than 20 million sperm/mL |
|
|
Term
| How is an egg protected from fertilization from multiple sperm? |
|
Definition
| calcium cascade upon entrance of first sperm |
|
|
Term
| What hormone is produced by germinal epithelial tumors? |
|
Definition
|
|
Term
| What is the female equivalent to the male's Leydig cells? |
|
Definition
| thecal cells, stimulated by LH |
|
|
Term
| What hormone are granulosa cells responsive to? |
|
Definition
|
|
Term
| What enzyme do granulosa cells lack but adrenal cells and thecal cells possess? |
|
Definition
| 17a-hydroxylase (12,20-desmolase), which is why granulosa is dependent on thecal cells for androgens |
|
|
Term
| What is the significant of granulosa cells being able to make cholesterol de novo? |
|
Definition
| not much, as the thecal cells can do this as well and granulosa cells have complete dependence on thecal cells for androgens to subsequently produce estrogens |
|
|
Term
| What are the effects of estradiol on LH, estradiol, and progesterone receptors? |
|
Definition
|
|
Term
| When does the second meiotic division of ova occur? |
|
Definition
|
|
Term
| What hormone causes endometrial proliferation? |
|
Definition
|
|
Term
| What fundamental pre-steroid substance does the corpus luteum require from other sources as it cannot produce the substance itself? |
|
Definition
|
|
Term
| What happens during prenancy with low levels of progesterone? |
|
Definition
|
|
Term
|
Definition
| review BRS questions from endocrine physiology section on sexual differentiation |
|
|
Term
| Why is estriol (E3) important in pregnancy? |
|
Definition
| it allows the mother to respond to weak estrogens during pregnancy w/out interfering with gender/phentotypic development of fetus (estrogen receptors are up-regulate during pregnancy allowing mother to have better response to lower levels of circulating estrogens) |
|
|
Term
| Why does mifepristone cause abortions? |
|
Definition
| because it is a progesterone receptor antagonist |
|
|
Term
| During what week of pregnancy are HCG levels at their peak? |
|
Definition
|
|
Term
| What contribution is made by the fetus' liver during pregnancy? |
|
Definition
| it produces DHEA-S (dehydroepiandrosterone-sulfate) <-- necessary for maintaining hormone levels |
|
|
Term
| What hormone shift occurs towards the end of pregnancy that eventually leads to parturition? |
|
Definition
| increase in estrogen/progesterone level (increased estrogen in comparison to progesterone) |
|
|
Term
| What happens with prolactin levels during pregnancy? |
|
Definition
| they steadily rise, but effects are inhibited by high levels of estrogens and progesterone |
|
|
Term
| Which female hormone causes increase in basal body temperature? |
|
Definition
|
|
Term
|
Definition
| the day after pill, prevents egg implantation w/in 72 after last sexual encounter |
|
|
Term
|
Definition
| smooth muscle tumor of uterus <-- estrogen dependent |
|
|
Term
| Common conidtion caused by aberrant presence of endometrial tissue outside of the uterus? |
|
Definition
|
|
Term
| What are the two most common presentations/complaints w. polycystic ovarian disease? |
|
Definition
|
|
Term
| What placental cells are responsible for secreting hCG? |
|
Definition
| blastocyst (during first 6-8 days after implantation) |
|
|
Term
| What enzyme is responsible for converting pregnenolone to progesterone? |
|
Definition
| 3B-OHSDH (3B-hydroxsteroid dehydrogenase) |
|
|
Term
| How is DHEA important insteroid synthesis? |
|
Definition
| is is a 21-carbon precursor for androgens; exhibits some adrogen activity |
|
|
