Spermatogenesis

Question 1

Location of spermatogenesis

Answer 1

Seminiferous tubules

Question 2

Pathway of sperm

Answer 2

S(R)EVEn UP: Seminiferous tubules –> (Rete testes) –> Epididymis –> Vas deferes –> Ejaculatory duct –> Urethra –> Penis

Question 3

Blood testes barrier

Answer 3

Tight junctions between Sertoli cells

Essential because the haploid germ cells are potentially antigenic and will be destroyed by the immune system

Question 4

Maturity of spermatogonia from periphery to center of seminiferous tubule (remember to do Bendiak’s quiz)

Answer 4

1. Spermatogonium (Diploid- 2N, 2C) –> undergoes replication to form primary spermatocyte
2. Primary Spermatocyte (Diploid- 2N, 4C) –> undergoes meiosis I to form sec. spermatocyte
3. Secondary Spermatocyte (Haploid- 1N, 2C)–> undergoes meiosis II to form spermatid
4. Spermatid (Haploid- 1N, 1C)–> undergoes spermiogenesis to form mature spermatozooan
5. Spermatozooan (Haploid- 1N, 1C)

Question 5

Main steps of spermatogenesis

Answer 5

Proliferative phase: replication

Meiotic phase: half the # of chromosomes (2N –> 1N) and then (2C –> 1C)

Spermiogenesis: haploid spermatid –> mature spermatozoa
( Golgi –> Cap –> Acrosomal –> Maturation)

Spermiation: final step of spermatogenesis in the Sertoli cell in which sperm is released from Sertoli cell to epididymis

Question 6

Regulation of spermatogenesis

Answer 6

Stimulated by testosterone (under control of the HPT axis)