Lec 31 Male reproduction Flashcards
What causes gonads to descend? where do they come from?
- start at inferior pole of kidney
- gubernaculum [tissue] causes them to descend
What is the arterial supply to testis?
directly from aorta = testicular arteries
What is the venous drainage from testis? on left vs right?
- venous drainage into pampiniform plexus
- from there
- – left: to left renal vein
- – right: directly to inferior vena cava
What cells in males target LH? effect?
- LH targets leydig cells
- stimulates to produce testosterone
What are neg feedback loops from leydog vs seminferous cells?
leydig: produce testosterone that inhibits more testosterone/GnRH release
seminiferous: produce inhibin that inhibits more FSH/GnRH release
What cells in males are target of FSH? effect?
- cells in seminiferous tubules [sertoli cells]
- tell sertoli to increase sperm production/maturation
How is testosterone normally transported in bloodstream?
- most bound to sex hormone binding globulin [SHB]
- — some also bound to serum albumin and corticosteroid binding globulin [CBG]
- 1-2% unbound/free and thus biologically active
What are levels of FSH/LH/testosterone in germinal cell aplasia?
high FSH – sertoli cells trying to secrete more sperm but not properly producing inhibin so no negative feedback
normal LH
normal testosterone
What are levels of FSH/LH/testosterone in primary testicular failure?
high FSH
high LH
normal or low testosterone
What are levels of FSH/LH/testosterone in hypogonadtropic hypogonadism?
low FSH
low LH
low testosterone
talman syndrome
- usually pituitary defect
- don’t produce FSH/LH
- also can’t smell well
5 stages of male puberty
stage 1: age 9-12, no visible signs, male hormones more active
stage 2: age 9-15: darkening aerola around nipple, testicles and scrotum grow, a little bit of pubic hair, height increases
stage 3: age 11-16: penis grows in length, more pubic hair, heigh increases, voice starts to change
stage 4: age 11-17: penis growth in width, testicles and scrotum continue to grow, facial hair increases, skin oilier, voice deepens
stage 5: age 14-18: boys reach full adult height, pubic hair and genitals look like mans, shaving needed
Do type A or type B spermatogonium become spermatocytes?
type B
What do you call sperm that just underwent meiosis I
primary spermatocytes
What do you call sperm that just underwent meiosis II
secondary spermatocytes
what is spermiogenesis? major things that happen?
process of changing cell from normal round to specialized elongated cell that can traverse reproductive tracts to fertilize egg
- golgi becomes acrosomal vesicle
- micochondria for mitochondrial sheath
- loses a lot of cytoplasm
- centrioles (?) become flagellum
What is normal concentration of sperm in ejaculate? percent motile? look normal?
20 x 10^6
about 50% should be motile
about 30% should look normal
What is path of sperm
testicle –> epididymis –> vas deferens –> ejaculatory duct –> urethra
What percent of ejaculate comes from prostate? seminal vesicles?
prostate: 50% of ejaculate
seminal vesicles: 45% of ejaculate
What is in prostate ejaculate? acidic or alkaline?
- slightly acidic
contains proteins PSA, PAP, Zinc = some antimicrobial components
What is in seminal vesicle ejaculate? acidic or alkaline?
- alkaline
- fructose = source of energy for sperm
What does bulbourethral/cowper’s glands secrete? purpose?
- pre-ejaculate
- lubricates urethra and neutralizes acid [ie urine]
Two ways erection can be triggered?
reflex
- by direct stimulation penile shaft
- picked up by peripheral nervous and spinal cord
psychogenic
- by emotional stimulation
- picked up by limbic system/cerebral cortex
both via parasympathetic action
Is erection sympathetic or parasympathetic?
parasympathetic
