Seminiferous tubule

Question 1

Spermatogonia (germ cells)

Answer 1

Maintain germ pool and produces 1st spermatocytes

Location: line seminiferous tubules

Question 2

Sertoli cells (non-germ cells)

Answer 2

1) Secrete inhibin -> inhibit FSH
2) Secrete androgen binding protein (ABP), which maintains local levels of testosterone
3) tight junctions -> blood testis barrier, isolates gametes from autoimmune attack
4) support and nourish developing spermatozoa and regulate spermatogenesis
5) produces MIF

Line semniferous tubules

Temperature sensitive:
low sperm production, low inhibit with high temp;
high temp seen in varicocele, cryptorchidism

“Sertoli = Sensitive”

Question 3

Leydig cells (endocrine)

Answer 3

Secrete testosterone;
testosterone production unaffected by temperature

Location: interstitium

Question 4

Spermatogenesis

Answer 4

Beings at puberty with spermatogonia;
Full development takes 2 months;
Occurs in seminiferous tubules
Produces spermatids that undergo spermiogenesis (loss of cytoplasmic contents, gain of acrosomal cap) to form mature spermatozoon.

Question 5

Mnemonics for spermatogenesis

Answer 5

Gonium is Going to be a sperm;
Zoon is Zooming into egg

Spermatid becomes spermatozoon after spermiogenesis.