Male Reproduction

Question 1

Name the five structures that make up the male duct system.

Answer 1

Epididymis, vas deferens, ampulla, ejaculatory duct, urethra

Question 2

After GnRH is released from the hypothalamus where does it travel to and what is its affect?

Answer 2

It binds to the plasma membrane of the gonadotrophs and stimulates the release of LH and FSH.

Question 3

What chain is the same in all the chemicals and which one leads to their specific actions?

Answer 3

The Alpha is the same and beta is specific.

Question 4

What is the role of the leydig cell?

Answer 4

It changes cholesterol into androgens which increases the overall testosterone. It can be sent to the sertoli cells to produce inhibin and estrogen.

Question 5

What is the role of Inhibin B?

Answer 5

It plays as a negative feedback to the anterior pituitary to stop the release of FSH.

Question 6

What is the role of the Sertoli cell?

Answer 6

It uses androgens to create estrogen, and FHS to produce inhibin. It is also able to secrete anti-mullerian hormone in the presence of testosterone.

Question 7

What is the main role of exogenous testosterone administration?

Answer 7

To have a negative feedback on GnRH and inhibit LH from spiking.

Question 8

How is testosterone transported through the body?

Answer 8

60% is bound to either androgen binding protein (ABP) or Sex Hormone Binding Protein (SHBP). 38% is bound to Albumin, and 2% is freely transported.

Question 9

In what week of gestation do the first sperm cells start to appear?

Answer 9

~6-7 weeks.

Question 10

You have a patient that is curious if they are still able to have children or not. You run a test that shows that they have very little amounts of LH and FSH and normal levels of testosterone. What would be your response to them?

Answer 10

in adults as long as you have adequate levels of testosterone or very small levels of LH and FSH are required for spermatogenesis. So he would be just fine with the production of sperm.

Question 11

Once a spermatogonia is formed where does it go to mature and how long does the process take?

Answer 11

it stays in the seminiferous tubules for ~50 days and then will travel to the epididymis for ~27 days to mature.

Question 12

What is the role of the middle piece of the sperm?

Answer 12

It contains mitochondria for ATP use

Question 13

What is the role of the principal piece of the sperm?

Answer 13

It stores the ATP for future use

Question 14

What is the role of the end piece of the sperm?

Answer 14

contains the flagella used for motility

Question 15

What are the two phases of puberty and their roles?

Answer 15

Gonadarche - the physical and functional maturation of the gonads
Adrenarche - the increase in adrenal androgens to induce pubarche

Question 16

approximately how late into life can a male still be producing peak amounts of sperm?

Answer 16

It starts to decrease around ~80 years old.

Question 17

Name the difference between Primary and secondary sex characteristics

Answer 17

Primary – testes size and sperm production

Secondary – growth spurt, pubic hair and beard, lowering of voice, muscle development.

Question 18

What is the main cause of men being taller than woman?

Answer 18

The closing of the epiphyseal regions of the long bones is done in response to estrogen. Since there are smaller amounts in males it takes longer for those to be closed.

Question 19

what makes up the seminal fluid?

Answer 19

60% is fructose and prostaglandins, 30% is epididymal fluid, and 10% is the semen.

Question 20

What is the role of the cowper’s and prostate gland during ejaculation

Answer 20

They both provide an alkaline fluid to help lower the acidity of the vagina. The prostate gland also secretes citrate as fuel.

Question 21

What causes an erection?

Answer 21

The release of ACh to bind to M3 receptors which leads to the release of NO which stimulates cGMP to cause vasodilation. This compresses the veins and decreases the venous drainage.

Question 22

What is the role of Emission?

Answer 22

To move the seminal fluid to the proximal part of the urethra and prepare it for ejaculation.

Question 23

Define ejaculation

Answer 23

It is a spinal reflex done with semen from the prostatic urethra enters the bulbous urethra.