Lecture 5 - Male Reproductive Tract I

Question 1

Exocrine and endocrine secretions of testes?

Answer 1

spermatozoa and testosterone res[ectively

Question 2

Primitive germ cells that become spermatozoa?

Answer 2

gonocytes

Question 3

Stem cell factor?

Answer 3

drives migration and survival of PGCs; failure leads to germ cell migration (e.g. pancreas) and could lead to germ cell tumours

Question 4

Immature/fetal testis?

Answer 4

sertoli cells, and large round immature germ cells at the periphery

Question 5

Germ cell tumours?

Answer 5

vast majority in testis, typically nervous tissue

Question 6

Leydig cells?

Answer 6

produce testosterone, not testosterone dependent for first 7-8 weeks, 14 weeks gestation production of test becomes LH/hCG dependent; adult cells differentite from stem cells at puberty

Question 7

Leydig cell location in fetl tissue?

Answer 7

interstium surrounding seminiferous cords

Question 8

Mini-puberty?

Answer 8

spike in testosterone secretion from Leydig cells 22 months post partum - masculinisation of neonatal brain, promoting sertoli cell proliferation, differentiation of gonocytes into spermatogonia

Question 9

Sertoli cell function?

Answer 9

nurses cells that promote post-mitotic development: nourish spermatogonia, reabsorbing excess cytoplasm, produce seminiferous tubule fluid, maintain stem cell niche

Question 10

Sertoli cell numbers?

Answer 10

proportional to sperm production capacity of seminiferous tubule - does not increase after puberty

Question 11

Sertoli cell extra function?

Answer 11

blood-testis barrier (prevent antisperm antibody production) and immune privileged for transplants (e.g. islet cells)

Question 12

Moving testes?

Answer 12

suspened by caudal and gubernaculum ligaments in lumbar region, caudal regresses via testosterone, insulin-like 3 (from Leydig cells) dilates inguinal canal and causes gubernaculum to move toward,

Question 13

Failure for testes to descend?

Answer 13

cryptorchidism - temperature induced infertility, cancer risk, prevented by breastfeeding