Male Reproductive System Flashcards
Function of epididymis
maturation of sperm, secretes H to acidify luminal fluid, storage, reabsorption
Function of vas deferns
stoarge, transportation of sperm
function of seminal vescle
secrete/store fructose semen, PG, ascorbic acid, fibrinogen, thrombin-like protins
function of prostate
secrete/store fluid rich in PSA
functino of bulbourethral gland
secrete mucous upon arousal
what is GnRH released by
hypothalmus
function of GnRH
releases LH and RSH
what is LH released by
ant. put
function of LH
binds to leydig cell receptors, stimulates testosterone proudction and secretion
function of FSH
stimulates sertoli cells to produce ABP and inhibin. Controls sertoli cell proliferatino and seminiferous tubule growth
affect of testosterone on other hormones
neg. feedback on GnRH and LH RSH
function of androgen binding protein
concentrates testosterone at site of spermatogensis
inhibin B
selectively inhibits FSH production
what does inhibit give neg feedback on
FSH
what can testosterone be converted to
SHT and estradiol
____ binds to receptors on leydig cells
LH
what happens when LH binds to receptors on leydig cells
increases intracellular cAMP and steroidogenic enzymes like cholesterol side chain cleavage enzyme, converting cholesterole into pregnenolone
the enzymes 3beta-HSD and 17beta-HSD convert pregnenolone into what
testosterone
Testosterone gets converted to ____ by 5 alpha reductase
DHT
Testerstone diffuses to sertoli cells then what
stimulates speramotgensis
PSH acts on what cells
sertoli
what happens when PSH acts on sertoli cells
induces synth/secretion of androgen binding protein (ABP) which facilitates spermatogenesis by concentrating testosterone in the Sertoli cells.
function of testosterone
internal genitalia development during gestation, skeletal muscle mass/strength in puberty, erythropoiesis
function of dihydrotestosterone
differentiation/maturation of external genitalia. Adult prostatic disease. Increased hair follicle growth during puberty
function of etradiol
acts on estrogen receptor, increases bone density and epiphyseal closure, libido
Spermatogenesis
Spermatogonia stem cells begin dividing at puberty, some remain spermatogonia and some become primary spermatocytes
primary spermatocytes form what
secondary speratocytes then speratids then spermatozoa
spermiogensis
spermatids changing into spermatozoa (controlled by FSH)
spermiation
release of mature sperm into lumen
examples of primary male hypogonadism
testicular dysfunction, decrease in testosterone. Cryptorchidism, Klinefelter syndrome (extra X)
examples of secondary male hypogonadism
Hypothalamus/pituitary dysfunction, decrease in gonadotropins. Low testosterone due to low LH/FSH. Kallmann syndrome
What are the stages of the male sexual act
erection
lubrication
emission
ejaculation
erection
parasymp
dilation of penile arteries
lubrication
parasymp
bulbourethral gland secretion
emmsion
symp
Ampulla of vas deferens contracts moving spermatozoa into proximal urethra. Contraction of seminal vesicles and prostate. Internal bladder sphincter contracts. Precedes/coincides w/ ejaculation
ejaculation
spinal reflex triggered by entry of semen into proximal urethra. Afferent impulses to sacral spinal cord, somatic motor efferents cause rhythmic contraction of muscles at base of penis and pelvic floor
what happens during an erection
Parasymp nerves induce vascular smooth muscle relaxation in penile arterioles through release of acetylcholine, NO, and vasoactive intestinal peptide -> vasodilation and engorgement of corpus cavernosum and corpus spongiosum. Veins compressed
what terminates an erection
sympathetic nerve impuses causing vasoconstriction
