Spermatogenesis Flashcards Preview

𝚙𝚑𝚢𝚜𝚒𝚘𝚕𝚘𝚐𝚢 𝟸 : 𝚛𝚎𝚙𝚛𝚘𝚍𝚞𝚌𝚝𝚒𝚘𝚗 > Spermatogenesis > Flashcards

Flashcards in Spermatogenesis Deck (48)
Loading flashcards...
1

Where are sperm made and stored?

→ In the testes
→ stored in the epididymis

2

What contracts during ejaculation?

→ The vas deferens

3

Where do the sperm travel to after the vas deferens?

→ Seminal vesicle which contribute seminal fluid
→ move to the prostate which also contribute secretions

4

Where does the vas deferens meet the urethra?

→ In the prostatic gland

5

What is responsible for erections?

→ Hydrostatic pressure

6

Where are the testes located?

→ in the scrotum outside the body cavity

7

Why are the testes located outside the body?

→ Optimum temperature for sperm production
→ overheating reduces sperm count

8

What is the normal volume of the testes and how is this measured?

→ 15-25ml
→ orchidometer

9

What do the tubules lead to?

→ Rete on one side

10

What does the rete lead to?

→ Epididymis and vas deferens

11

What is 90% of the testis made up of?

→ seminiferous tubules

12

Where is the site of spermatogenesis?

→ Seminiferous tubules

13

How long does it take for sperm to go from the basal side to the lumen?

→ 74 days

14

What are sertoli cells held together by?

→ Tight junctions

15

What are tight junctions for?

→ preventing an immune response against sperm cells

16

Describe the formation of spermatozoa

→ The sperm start as spermatogonia which are diploid
→ they replicate by mitosis and form 2 types of cell
→ type A and type B
→ type A is used as the template and replicates again
→ type B moves into the adluminal compartment and becomes a primary spermatocyte
→ the primary spermatocyte undergoes meiosis I and become secondary spermatocyted
→ 2ndary spermatocytes divide to form 4 daughter cells (meiosis II)
→ these are spermatids

17

What are the walls of the seminiferous tubules made from?

→ Tall columnar endothelial cells which are Sertoli cells

18

What are spaces between the seminiferous tubules filled with?

→ blood
→ lymphatic vessels
→ Leydig cells

19

How long does the cycle of spermatogenesis take?

→ 74 days

20

How often do new cycles of spermatogenesis occur?

→ every 16 days

21

Summarise spermatogenesis in 3 steps?

→ mitotic proliferation of spermatogonia
→ Meiosis and development of spermatocytes
→ spermiogenesis , elongation, loss of cytoplasm and movement of cellular content

22

What do spermatids remain connected by and why?

→ A cytoplasmic bridge
→ they form a syncytium allowing synchronous development

23

What are the 2 differences between oogonia and spermatogonia?

→ Cannot make more oocytes by mitosis
→ sperm can divide mitotically
→ limited supply of eggs

24

What do Leydig cells do?

→ LH binds
→ Convert cholesterol into testosterone

25

What receptors do Sertoli cells have?

→ FSH

26

What is the function of Leydig and Sertoli cells?

→ Leydig cells make testosterone
→ Sertoli cells make ABP which makes testosterone more soluble so it can be concentrated in the lumen

27

What happens if you take anabolic steroids?

→ Decrease in LH and FSH
→ Testicular atrophy occurs

28

What happens during an erection?

→ Vasodilation of the corpus cavernosum
→ Partial constriction of the venous return

29

What does the autonomic nervous system do during an erection?

→ Coordinated smooth muscle contraction of the vas deferens, glands and urethra

30

What does the parasympathetic system do during an erection?

→ controls erections