Male Reproductive

Question 1

What’s the function of the male reproductive tract?

Answer 1

Forming sperm (gametes) 
And depositing these to the female

Question 2

What makes a male male? Pt1 (what are male and female gonads derived from?)

Answer 2

Male and female gonads (organ that produces gametes) are derived from the same embryological tissue

Question 3

When do males become males?

Answer 3

Until week 6 it’s undifferentiated, on week 7 a gene on the Y chromosome (SRY) gene is expressed and testes develop. If this gene isn’t expressed, testes don’t develop and in week 11 ovaries develop

Question 4

What are the male and female ducts called?

Answer 4

Male- wolffian ducts

Female- Müllerian ducts

Question 5

What’s the functional unit of the male reproductive tract?

Answer 5

The testes

Question 6

Explain the anatomy of the testes?

Answer 6

Seminiferous tubules (800 per testicle) very coiled/highly convoluted tubule
There’s 2 cell types- sertoli cells (epethelial cells)
Adjacent to Sertoli cells are sperm cells
Between the tubules are leydig cells (make testosterone)

Question 7

What does simple ducting ensure ?

Answer 7

Delivery of sperm to a penis

Question 8

What’s the function of the vas deferens?

Answer 8

Drains the epididymis of any sperm
During ejaculation, sperm moves from epididymis through the muscular VS
Vas deferens end/terminate in the ejactulatory duct near the PG

Question 9

What is semen? (Where is it secreted from?)

Answer 9

Fluid which is ejaculated from the sperm + secretions
Secretions from:?
-seminal vesicles: mucus,fructose and prostaglandins contribute 60% semen volume
-prostate gland (alkaline buffer, clotting factors, PSA
-bulbourethral glands

Question 10

What does the ejactulatory duct do?

Answer 10

Open into the urethra

Question 11

What’s the role of the testes?

Answer 11

• produce sperm

- produce androgens (especially testosterone)

Question 12

What is spermatogenesis?

Answer 12

• production of mature sperm (CONTINUOUS PROCESS)

- each ejaculate (2-10ml) contains 100million sperm per ml

Question 13

Where does spermatogenesis occur?

Answer 13

In the seminiferous tubules

Question 14

Some stem cells give rise to sperm, what are these called ? And where are these stem cells located ?

Answer 14

Spermatogonia
These stem cells are located at the periphery of the tube
Developing sperm cells move towards the lumen as they mature

Question 15

What line the cells of the seminiferous tubules?

Answer 15

Sertoli cells:
These are a source of nutrition to the sperm
-phagocytosis of dead sperm
-formation of blood testes barrier
-production of seminiferous tubules fluid

Question 16

What’s testosterone produced by?

Answer 16

Leydig cells under the influence of LH (from the anterior pituitary gland)

Question 17

Testosterone is an example of what?

Answer 17

An androgen

Question 18

What has a direct paracrine effect on spermatogenesis?

Answer 18

Testosterone (the remainder is secreted into the vascular system)

Question 19

Gonadotrophin releasing hormone is produced by ?

Answer 19

Parvocellular neurons in the pre-optic area and elsewhere

Question 20

What does GnRH do?

Answer 20

It binds to its receptors

Question 21

Sperm cells are produced from stem cells called s?

Answer 21

Spermatogonia

Question 22

Majority of other endocrine actions are via its metabolite?

Answer 22

5-a DHT (5a dihydrotestosterone)
Due to the action of 5a reductase
T= primary sexual characteristics
DHT= secondary sexual characteristic (hair growth)

Question 23

How do T and 5a-DHT act via?

Answer 23

They act via androgen receptors. They act as nuclear transcription factors (influence transcription of a gene)

Question 24

What controls male reproduction?

Answer 24

Gonadotrophin releasing hormone (GnRH)
GnRH binds to its receptors in the gonadotropes of the anterior pituitary gland and stimulates secretion of LH and FSH
Leydig cells respond to LH via a cAMP pathway which results in testosterone production
Sertoli cells respond to FSH:
-have growth cells to increase stem cell activity
-Androgen binding protein: transport molecule
Inhibin b- produces a negative feedback effect