S1 The male reproductive system

Question 1

describe how the hypothalamus pituitary gonadal axis functions ?

Answer 1

Hypothalamus releases GnRh to pituitary gland which in turn releases FSH and LH.
FSH and LH act on the growing follicle in the ovaries which stimulate it to release oestrogen which stimulates ovulation
LH also acts on the corpus luteum to stimulate release of progesterone and some oestrogen

Question 2

describe the negative feedback loop of the HPG axis ?

Answer 2

increase in progesterone, oestrogen after ovulation inhibit FSH,LH secretion - inhibits pituitrary gland
also inhibits hypothalmus releasing GnRH

Question 3

describe the positive feedback loop of the HPG axis ?

Answer 3

increased oestrogen at midcycle stimulates LH secretion - stimulates pituitary gland

Question 4

where does spermatogenesis occur ?

Answer 4

seminiferous tubule

Question 5

what happens after spermatogenesis in the testes ?

Answer 5

enter the rete testis and efferent ductules where they become concentrated - water is drawn out. they then mature in the epididymis and leave via the vas deferens

Question 6

what is a hydrocele

Answer 6

can form in the tunica vaginalis which is the accumulation of blood

Question 7

what do sertoli cells do

Answer 7

sperm maturation - removing the sperms cytoplasm

Question 8

what do leydigs cells do ?

Answer 8

production of testosterone

Question 9

what is testicular torsion ?

Answer 9

testes twist on their spermatic cord occluding the veins, can lead to scrotal swelling and infertility

Question 10

what does the spermatic cord form

Answer 10

the testes invaginate the abdominal wall as they are pulled through by the gubernaculum forming the spermatic fascia that surrounds the testis and its vessels

Question 11

what 3 fascial layers the spermatic cord have

Answer 11

internal, cremasteric, external

Question 12

what vessels do the spermatic cord contain

Answer 12

arteries - testicular artery, artery to the vas, cremasteric artery
vein - testicular vein, vein to the vas, cremasteric vas

Question 13

describe the veins of the spermatic cord ?

Answer 13

illoinguinal - however this is outside the spermatic cord
cremasteric - which supplies muscles in the cremasteric fascia that lower the testes
sympathetic - supplies the vas and causes ejaculation (parasympathetic causes erection)

Question 14

describe the process of a vasectomy ?

Answer 14

cut through the scrotum, pull out the spermatic cord, cut and tie it off

Question 15

how is the ejaculate formed ?

Answer 15

10% - testes
SV- 65%
Prostate - 25% (alkaline secretion to counteract the acidity of the female tract)

Question 16

is the urethra compressed in the benign prostatic hypertrophy ?

Answer 16

in benign prostatic hypertrophy, the transitional zone of the prostate enlarges compressing the urethra

Question 17

describe the mechanism of an erection

Answer 17

vasodilatation in penile arterioles and compression of veins results in erection

Question 18

what is a varicocele ?

Answer 18

when veins in the pampiniform plexus becomes enlarged in the scrotum. it most communly occurs on the left side as the left vein goes to the renal vein and then the inferior vena cava whereas the right goes straight to the IVC. if it was to happen on the right side, it would be due to thrombosis

Question 19

what is the structure of the penis ?

Answer 19

corpus cavernosa (eyes)
corpus spongiosum