repro

Question 1

what is nondisjunction?

Answer 1

when chromos do not separate properly after division

Question 2

what are the various types of abnormal sex distribution syndromes?

Answer 2

Klinefelters, XXY; 
Turner's syndrome, X
Y is non viable
XYY...
XXX-->no distinct phenotypes

Question 3

when do repro structures differentiate?

Answer 3

seventh week of development –prior to this time they are considered bipotential

Question 4

Male or female development depends on the presence or absence of sex determining region of the Y chromosome (SRY gene)

Answer 4

ya

Question 5

how to the bipotential gonads form female gonads?

Answer 5

gonadal cortex forms ovary while the medulla regresses; wollfian duct also regress because of lack of testosterone; mullerian duct becomes fall tube, uterus, cervix, and upper half of vag

Question 6

how to the bipotential gonads form male gonads?

Answer 6

gonadal cortex regresses; medulla forms testis; wolffian duct forms epididymis, vas def, and seminal vesicles (presence of testosterone); mullerian duct regresses due to AMH

Question 7

how does the SRY gene dictate sex?

Answer 7

SRY gene produces TDF (testis determining factor)–>creates SOX9, WT1, SF1–.guides development of gonadal medulla into a testis; testes then produce:

• Anti-Mullerian hormone (sertoli cells): causes mullerian ducts to regress
• Testosterone (leydig cells): converts Wolffian ducts into male accessory structures (epididymis, vas deferens, and seminal vesicles)
• Dihydrotestosterone (leydig cells): differentiation of external genitalia–development of prostate

Question 8

what causes formation of external genetalia?

Answer 8

External genitalia development driven by presence or absence of androgens (DHT)

Question 9

describe female gametogenesis

Answer 9

during embryogenesis, oogonium undergo mitosis then meosis I–generate primary oocytes; at puberty, primary oocyte splits into secondary oocyte and polar body; secondary oocyte released as egg during ovulation, then will complete meiosis II when fertilized

Question 10

describe GnRH release

Answer 10

• Released from hypothalamus in pulsa)le fashion every 1-3 hours in both sexes
• -females also have a surge corresponding with ovula)on
• children with a GnRH deficiency will not mature sexually without gonadtrophin s)mula)on of the gonads
• synthe)c GnRH must be delivered in a pulsa)le manner
• constant delivery of GnRH leads to down regula)on of receptors in the pituitary gonadotropes
• high GnRH treatment for certain breast or prostate cancer

Question 11

what is the erectile tissue of the penis?

Answer 11

• Corpus spongiosum

- Corpora cavernosa

Question 12

what is involved in prostate development?

Answer 12

DHT

Question 13

how can prostate cancer be treated?

Answer 13

-administra)on of 5a-reductase inhibitor (finasteride) blocks DHT production, shrinks hypertrophied prostate

Question 14

describe the seminif tub

Answer 14

• -site of sperm production
• -Developing spermatocytes stack in columns from outer edge to lumen with sertoli cells between each column
• –found in inters))al )ssue produce testosterone during development then again ader puberty

Question 15

Basal lamina of seminif tubule keep out large par)cles but allows testosterone to enter

Answer 15

improtant for developing sperm

Question 16

describe sertoli cells

Answer 16

• cntain tight junction with adjacent sertoli cells forming a blood- tes)s barrier between tubule lumen and inters))al space
• regulate sperm development -“sustentacular cells” provide sustenance or nourishment
• Produce a variety of substances: hormones (ac)vin & inhibin); growth factors; enzymes; and androgen binding protein (ABP) which binds to testosterone to keep it in the tubule lumen

Question 17

describe how GnRH neurons activate to release hormones

Answer 17

GnRH-containing neurons are cyclically activated to fire APs–>release trophic hormones (GnRH) which are released into the first capillary bed; they are then carried to endocrine cells with GnRH receptors in anterior pit gland where a second cap bed lies; they acts on endocrine cells to release their peptide hormones–>LH and FSH–>enters blood stream and goes to gonads

Question 18

what is the blood testes barrier

Answer 18

a lining of sertoli cells which provide a barrier between the blood and seminif tubs; improtant, because gametogenesis is very sensitive–xenos in blood could destroy developing sperm

Question 19

where do spermatids compete transformation, and what occurs?

Answer 19

–remain embedded in apical membrane of sertoli cells–>lose most cytoplasm, form a flagellum; chromatin condenses, acrosome forms and caps the nucleus; a mid piece forms which is needed for energy (contains mito);

Question 20

how long does it take to go from spermatogonium to free sperm?

Answer 20

64 days, with 200 million produced

Question 21

where do sperm mature?

Answer 21

-mature in the epididymis (epididymal cells secrete proteins) during 12 or so days of transit time

Question 22

what hormones does spermatogenesis require?

Answer 22

• FSH binds to receptors on sertoli cells causing them to generate paracrine molecules needed for spermatogonia mitosis and spermatogenesis
• also produce ABP and inhibin
• LH targets the inters//al leydig cells resul)ng in produc)on of testosterone -essen)al for spermatogenesis and ac)ons appear to be through sertoli cells but exact mechanism not completely understood -spermatocytes do not have receptors for FSH, LH or androgens

Question 23

what do the accessory glands excrete which contribute to the composition of semen?

Answer 23

1. Nutrients
2. Buffers for protec)on against acidic vaginal
   environment and residual acidic urine in urethra
3. Chemicals to increase sperm mo)lity
4. Prostaglandins (mo)lity and contrac)on of male and female reproduc)ve tracts)
5. Immunoglobulin’s, lysozyme and other an)bacterial compounds

Question 24

what are the primary sex characteristics (men)?

Answer 24

Primary sex characteris/cs: internal sexual organs and external genitalia, which we learned are differen)ated to male during embryonic development by androgens and their growth afer puberty is also due to androgens.

Question 25

what are the secondary sex characteristics?

Answer 25

Secondary sex characteris/cs: facial and body hair growth, muscular development, thickening of vocal chords (lowering of voice) and behavioral effects i.e. sex drive (libido)

Question 26

Androgens are anabolic hormones and promote protein synthesis -brain -kidneys -heart -skin -liver

Answer 26

ya

Question 27

vulva/pudendum--external female genetalia

Answer 27

ya

Question 28

what are the layers of the uterus?

Answer 28

perimetrium--thin outer connective tissue myometrium-- thick layer of smooth muscle endometrium--inner layer

Question 29

how do the fall tubes move eggs down to the uterus?

Answer 29

through 2 layers of sm muscle and cilia

Question 30

what are th phases for ovarian cycle?

Answer 30

``` Follicular phase: marked by follicular growth, variable 10 days to 3 weeks Ovula/on: once one or more follicles have ripened, the ovary releases oocyte(s) during ovula)on Luteal phase (post ovulatory phase): ruptured follicle transforms to corpus luteum (yellow), named for yellow pigment and lipid deposits. -secretes hormones, ceases to func)on afer two weeks if no implantation ```

Question 31

what is the antrum?

Answer 31

a liquid component of the tertiary follicle whcih contains enzymes

Question 32

describe the phases of the uterine cycle

Answer 32

menses--0-7 proliferation-7-14 (latter part of the follicular phase, the uterus adds new cells to the endometrium layer in an)cipa)on of pregnancy) secretory phase--14-28-- (after ovulation hormones from corpus luteum covert thickened endometrium into a secretory structure -if pregnancy does not occur the superficial endometrium layers are lost during menstruation and the cycle begins again)

Question 33

Hormonal control of the menstrual cycle is complex - GnRH from hypothalamus - FSH and LH from the anterior pituitary -Estrogen, progesterone, inhibin and AMH from the ovary - During the follicular phase estrogen is dominant - ovula)on is triggered by surges in LH and FSH -during luteal phase progesterone dominant

Answer 33

ya

Question 34

vasectomy cauterizes/ties and cuts the vas deferens

Answer 34

VASectomy

Question 35

how do hormonal contraceptives work for women?

Answer 35

Various combina)ons of estrogen and progesterone inhibit gonadotropin secre)on (LH and FSH) from the anterior pituitary necessary for ovula)on. Progesterone also thickens cervical mucus

Question 36

what is RISUG/VasalGel?

Answer 36

- reversible inhibi)on of sperm under guidance - injec)on of polymer gel into vas deferens - -gel may create acidic enviro toxic to sperm;

Question 37

what can infertility arise from in men?

Answer 37

abnormal sperm motility, abnormal sperm in general, low sperm count, infections/scar tissue, retrograde ejac, sperm antibodies

Question 38

what can infertility arise from in women?

Answer 38

damages fall tubes, (scar tissue); ovulation disorders--hypothalamic dysfunctions; premature menopause, PCOS endometriosis--scar tissues cervical stenosis--polyps or fibroids grow on uterus or endometrium and prevent implantation

Question 39

what controls sperm to capacitate?

Answer 39

substances in uterus--albumin, lipoproteins, proteolytic enzymes

Question 40

when can an egg be fertilized after ovulation?

Answer 40

An egg is viable to be fer)lized for 12-24 hours post ovula)on

Question 41

where does fert occur?

Answer 41

in distal portion of fall tub

Question 42

developing follicle releases estrogen--contributes to proliferation of endometrium; when the ovum is released from the follice, endometrial thickness stagnates; the corpus luteum forms and gives of progesterone (and estrogen) which maintains endometrial thickness; when there is no implantation, corpus luteum disintegrates and endometrium can no longer be maintained without progesterone--sheds

Answer 42

ya

Question 43

which cells in the follice contain LH and FSH receptors?

Answer 43

theca cells contain LH receptors, granulosa cells contain FSH receptors

Question 44

describe the early to mid follicular phase

Answer 44

First day of menstrua)on is day 1 - FSH and LH released, several ter)ary follicles mature - Granulosa (FSH) and thecal (LH) cells begin to produce hormones - Androgens (androstenedione) converted to estrogens (aromatase) in granulosa cells -AMH prevents addi)onal follicle recruitment -estrogen nega)ve feedback anterior pituitary, posi)ve on granulosa cells -estrogen causes endometrium prolifera)on

Question 45

describe the late follicular phase

Answer 45

- estrogen release peaks from follicles -some follicles undergo atresia, dominant follicle persists and granulosa cells now begin to also release progesterone and inhibin - persistently high estrogen flips to posi)ve feedback on hypothalamus - LH surges to greater degree than FSH (inhibin) - high estrogen readies endometrium of uterus for implanta)on

Question 46

describe ovulation

Answer 46

occurs 16-24h after LH spike --LH needed for final steps of oocyte maturation meosis resumes Mature follicle secretes prostaglandins and proteoly)c enzymes -proteoly)c enzymes breakdown collagen and connec)ve )ssue holding follicle together--break out of ovary as well -prostaglandins may contribute to rupture of follicle and/or ovary wall -secondary oocyte is swept into fallopian tube by fimbriae

Question 47

describe early-to mid luteal phase

Answer 47

Both thecal and granular cells transform into luteal cells - lipid droplets and glycogen granules accumulate in cytoplasm and it begins to secrete progesterone -estrogen and progesterone levels steadily rise and provide nega)ve feedback to hypothalamus and anterior pituitary - progesterone (dominant during luteal) con)nues to influence endometrium (secretory) in prepara)on for pregnancy - cervical plug preven)ng bacteria and sperm

Question 48

describe the late follicular phase

Answer 48

Corpus luteum has life span of ~12 days -if pregnancy does not occur, spontaneous apoptosis, to become corpus albicans -progesterone and estrogen fall, FSH and LH increases -maintenance of endometrium depends on progesterone, when it decreases, vessels in surface contract causing surface cells to die -about 14 days aRer ovula)on, 2 days aRer corpus luteum ceases func)on menstrua)on begins -40ml blood, 35 ml of serous fluid and cell debris surge in LH causes thinning of mucus—more water—sperm can pass through and fertilize the egg