Spermatogenesis Flashcards Preview

ESA 4 - Reproductive System > Spermatogenesis > Flashcards

Flashcards in Spermatogenesis Deck (41):
1

What are spermatogonia? 

The 'raw material' for spermatogenesis 

2

How long are spermatogonia available for? 

Up to 70 years 

3

How do spermatagonia divide? 

Mitosis 

4

What does mitotic division of spermatogonia give rise to? 

  • Ad spermatogonium 
  • Ap spermatogonium 

 

5

What do Ad spermatagonium do? 

Maintain stock

6

What do Ap spermatagonium do? 

Give rise to primary spermatocytes 

7

What happens to primary spermatocytes? 

They divide by meiosis, giving rise to secondary spermatocytes 

8

What do secondary spermatocytes give rise to? 

Spermatids 

9

What does each primary spermatocyte form? 

4 haploid spermatids

10

What happens to spermatids once produced? 

They are released into the lumen of the seminiferous tubules in a process called spermination 

11

What happens to the spermatids as they pass down the seminiferous tubule? 

They remodel 

12

What path do spermatids take from the seminiferous tubule? 

They pass through the rete testis and ductuli efferentes 

13

Are sperm motile when passing through the seminiferous tubule to the ductuli efferentes? 

No 

14

If spermatids are non-motile, how can they pass through the seminiferous tubules to ductuli efferentes? 

Transport via Sertoli cell secretions, assisted by peristaltic contraction, until they reach the epididymis

15

What happens to spermatids in the epididymis? 

They form spermatozoa 

16

What is sperm capacitation? 

The final maturation step required before sperm become fertile 

17

Where does sperm capacitation happen? 

In the female genital tract

18

What happens in sperm capacititation? 

  • Removal of glycoproteins and cholesterol from sperm membrane 
  • Activation of sperm signalling pathways

 

19

What is involved in the activation of sperm signalling pathways? 

Atypical soluble adenylyl cyclase and PKA

20

What does sperm capacitation allow? 

Sperm to bind to zona pellucida of oocyte and initiate aerosome reaction 

21

What must happen to human sperm for in vitro fertilisation? 

It must first be incubated in capacitation media 

22

What is the spermatic cycle defined as? 

The time taken for reappearance of the same stage within a given segment of tubule 

 

23

How long is the spermatic cycle in humans? 

About 16 days 

24

Why does the spermatic cycle occur? 

Because not all stages in spermatogenesis are visible in a single cross-section of the seminiferous tubule 

25

Why are not all stages in spermatogenesis not visible in a single cross-section of the seminiferous tubule? 

Cells tend to appear in groups with the same maturation stages 

26

What is the spermatogenic wave?

The distance between the 'same stage' 

27

Why can the spermatogenic wave be defined? 

Because different stages in spermatogenesis are ordered in time as well as space, and each stage follows an orderly sequence along the length of the tubule 

28

What is the rete testis?

Part of the testis

29

What is the role of the rete testis?

Spermatids move down rete testis to reach epididymis 

30

What is the epididymis the location for? 

Spermatozoa formation

31

Is the epididymis part of the testis? 

yes

32

What structures are involved in the delivery of sperm? 

  • Seminal vesicles 
  • Prostate
  • Bulbourethral glands
  • Vas deferens

 

33

How does sperm enter semen? 

It travels down the vas deferens

34

What % of semen does seminal vesicle secretions constitute? 

70%

35

What do seminal vesicle secretions consist of? 

  • Amino acids
  • Citrate
  • Fructose
  • Prostaglandins

 

36

What % of semen do prostate secretions constitute? 

25%

37

What do prostate secretions consist of? 

  • Proteolytic enzymes 
  • Zinc

 

38

What are bulbourethral glands also called? 

Cowper glands 

39

What % of semen does bulbourethral glands secretions constitute? 

1%

40

What do bulbourethral gland secretions consist of? 

Mucoproteins

41

What is the function of mucoproteins? 

  • Helps lubricate
  • Neutralises acidic urine in distral urethra