male reproductive system and spermatogenis Flashcards
describe structure of male reproductive system
ureter, peritoneum, deferent duct, bladder, pubic symphysis, prostate gland, urethra, corpus cavernosum, corpus spongiosum, glans penis, scrotum, testis, anus, rectum, seminal vesicle, rectovestical pouch, sacrum
describe the scrotum
pouch of pigmented skin, fibrous tissue and muscle divided into to two compartments containing:
1 testis and 1 epididymis + testicular end of spermatic cord
describe the testes
male reproductive glands, in scrotum
3 layers: tunica vaginalis
tunica albuginea
tunica vasculosad
describe the tunica vaginalis
outer layer covering membrane formed from peritoneum
describe tunica albuginea
fibrous covering, forms septa which divides testes into lobes
describe tunica vasculosa
network of capillaries
describe the internal structure of testis
spermatic cord
testicular arteries and veins
deferent duct
head of epididymis
efferent ductules
body of epididymis
tail of epididymis
septum
seminiferous tubules
lobule
tunica vasculosa
tunica albuginea
tunica vaginalis
skin
cremaster muscle
describe seminiferous tubules
convoluted loops of germinal epithelium
produce spermatozoa
describe epididymis
single highly convoluted tubule forming a mass at upper pole of testis
describe the seminal vesicle
secrete seminal fluid which neutralises the acidic environment of the female reproductive tract at coitus
provides energy for spermatozoa
assists coagulation of semen after coitus
describe the prostate
produces milky coloured prostatic fluid composing 30% of the volume of semen
slightly acidic to help semen coagulate after coitus then break down this clot
describe the penis
external male sex organ
passage for ejaculation of semen and excretion of urine
composed of 3 columns of erectile tissue:
corpus cavernosa
corpus spongiosum
describe spermatogenesis
process of the formation of the male gametes in testesd
outline the 1st stage of spermatogenesis
primordial germ cell differentiaes into a diploid cell called spermatogonium goes through mitosis and makes 2 diploid primary spermatocytes
outline 2nd stage of spematogensis
primary spermatocyte goes through meiosis 1 into two haploid secondary spermatocyte > meiosis 2 then 4 haploid spermatids and then spermiogenesis gives 4 haploid spermatozoa
describe structure of a spermatozoa
head: acrosome containing enzymes for penetration and nucleus
midpiece: mitochondria
tail: flagellum for movement
describe the hormonal control of testes
stimulus from other areas of brain in hypothalamus > releases hormone > causing anterior pituitary to release FSH and LH
LH > stimulates testosterone production which stimulates spermatogenesis
FSH> stimulates spermatogenesis
describe the stages of fertilisation
- sperm makes contact with egg
- acrosome reacts with zona pellucida
- acrosome reacts with perivitelline space
- plasma membrane of sperm and egg fuse
- sperm nucleus enters egg
- cortical granules fuse with egg plasma membrane, which renders the vitelline layer impenetrable to sperm
- the egg completes mieosis 2 to become an ovum
- gamete fusion - becomes a zygote
