Spermatogenesis

Question 1

Where is sperm produced and stored? (2)

Answer 1

Produced in the seminiferous tubules

Stored in then epididymis

Question 2

What is the passage of sperm upon ejaculation ? (6)

Answer 2

Sperm moves up the vas deferens to the seminal vesicles to the the urethra which travels through the shaft of the penis and the glans where it exits the penis through the urethral opening

Question 3

What role do the testes have + how are they adapted for this role? (8)

Answer 3

Produce sperm + store it
Produce hormone which regulate spermatogenesis
Lie in scrotum outside body cavity (optimum temp. for sperm production is 1.5-2.5 degrees below body temp
Overheating reduces sperm count
Well-vascularised
Well innervated
Normal volume of testes ~15-25 ml
By orchidometer examination

Question 4

What is the structure of the testicles? (3)

Answer 4

Testis is 90% seminiferous tubules which are tightly coiled + arranged into lobules - 600m long in each testis
Lead to an area called rete-testis
Rete leads epiddiymis + vas deferens

Question 5

What happens in the seminiferous tubules? (4)

Answer 5

Spermatogenesis
Males PGCs on outer edge of SFs
These can reproduce themselves to maintain a supply of germ cells
Or can differentiate into sperm by meiosis - move inwards to the lumen + develop into sperm

Question 6

Tight junctions in seminiferous tubules?

Answer 6

Tight junctions b/w Sertoli cells form blood-testis barrier - protect spermatagonia from immune attack
Divides into luminal + adluminal compartment