Lecture 07: Spermatogenesis (Pozor)

Question 1

spermatogenesis

Answer 1

formation of spermatozoa from spermatogonia (proliferation)

Question 2

spermatocytogenesis

Answer 2

mitotic divisions involving proliferation and maintenance of spermatogonia

Question 3

meiosis in spermatogenesis

Answer 3

reduction of genetic material. Involves primary and secondary spermatocytes

Question 4

spermiogenesis

Answer 4

morphologic transformation of spherical spermatids into spermatozoa (differentiation)

Question 5

chromosomes/chromatids in primary and secondary spermatocytes, spermatids, and spermatozoa?

Answer 5

primary: 2n,4C
secondary: 1n, 2C (because meiosis I has occured)
spermatids: 1n, 1c (because meiosis II has occured)
spermatozoa: 1n, 1c

Question 6

role of centrioles in spermatogenesis

Answer 6

well organized tubules that move toward nuclear pole and help form tail and system of attachment for tail in sperm

Question 7

4 phases of spermiogenesis

Answer 7

1) Golgi
2) Cap
3) Acrosomal
4) Maturation

Question 8

Golgi phase of spermiogenesis

Answer 8

1st phase. formation of acrosomic granule

Question 9

Cap phase of spermiogenesis

Answer 9

2nd phase. growth of acrosomic head cap

Question 10

Acrosomal phase of spermiogenesis

Answer 10

3rd phase. condensation, elongation, shaping of sperm

Question 11

Maturation phase of spermiogenesis

Answer 11

4th and final phase. final formation of flagellum and neck piece, final condensation and shaping of nucleus

Question 12

Where is estrogen produced in the male?

Answer 12

tail of epididymis

Question 13

Importance of disulfide crosslinking in spermatogenesis

Answer 13

allows DNA to be densely packed into sperm heads

Question 14

What do sertoli cells produce?

Answer 14

inhibin and activin

Question 15

what do leydig cells?

Answer 15

testosterone

Question 16

Main hormone involved in spermatogenesis (especially to initiate it) ****

Answer 16

FSH

Question 17

what inhibits FSH?

Answer 17

inhibin

Question 18

What does LH do in spermatogenesis?

Answer 18

stimulate leydig cells to produce testosterone

Question 19

Role of FSH in spermatogenesis

Answer 19

acts on sertoli cells, causing them to release estrogen, DHT, inhibin

Question 20

Which hormones have negative feedback to AP during spermatogenesis?

Answer 20

Inhibin, testosterone

Question 21

What does endpiece of sperm’s tail lack?

Answer 21

axoneme (cytoskeletal core) and fibrous sheath

Question 22

Sperm tail organization

Answer 22

9+2 axoneme (central unpaired doublet surrounded by 9 paired doublets of microtubules arranged like spokes on a wheel)

Question 23

dynein

Answer 23

motor protein that contributes to whip-like motion of sperm’s tail