Lecture 20

Question 1

What is the role of the testes?

Answer 1

Make sperm

Question 2

What is the role of the epididymus?

Answer 2

bring the sperm to maturity

Question 3

What is the role of the Vas Deferens?

Answer 3

transports mature sperm to the urethra in preparation for ejaculation

Question 4

What are the tissue layers of the scrotum?

Answer 4

• skin, dartos muscle, superficial fascia, cremaster, scrotal cavity

Question 5

What are the tissue layers of the penis?

Answer 5

Skin, dartos muscle, elastic tissue +dorsal veins, erectile tissue

Question 6

What are the steps of spermatogenesis? How long does it take?

Answer 6

1. Spermatogonium—-mitosis
2. Spermatocyte (meiosis I forms secondary spermatocytes)
3. Spermatids (meiosis II forms 4 haploid spermatids)
4. Sperm (through maturation)
   ~64 days

Question 7

Why are balls outside of the body cavity? Why do they need to be cold

Answer 7

Sperm function optimally at a slightly colder temperature than the rest of the body

Question 8

What is the role of the PNS, SNS and somatic nervous system in the male sexual response?

Answer 8

PNS: innervate erectile tissue, release NO and ACh to relax smooth muscle and increase blood flow
SNS: innervate epididymus, vas deferens, seminal vesicles
Somatic: innervate skeletal muscles at the base of the penis— during ejactulation a spinal reflex produces rhythmic contractions in these muscles which helps to push semen out of the urethra

Question 9

What is the organization of the HPG axis?

Answer 9

Hypothalamus (GnRH) - pituitary gland (LH+FSH) - testes: androgens and inhibin

Question 10

What is the pulsatile secretion pattern?

Answer 10

Synaptic and hormonal influences on GnRH neurons in the hypothalamus in a masculinized brain create regular bursts of action potentials that increase LH and FSH once every two hours

Question 11

What are the sites of hormone action in the HPG axis?

Answer 11

Androgens act on nurse cells (sertoli) and leydig cells

Question 12

What are the sources of negative feedback in the HPG axis?

Answer 12

Androgen negative feedback occurs mostly at the hypothalamus,
Inhibin has a role in inhibiting secretion from gonadotropes of the anterior pituitary

Question 13

What is the function of the glands and ducts of the male reproductive system?

Answer 13

Contributes to the maturation of sperm, or secreting fluids to help keep sperm viable

Question 14

What are the two outer layers of the testes?

Answer 14

Tunica vaginalis, tunica albuginea

Question 15

What are the three types of cells in the seminiferous tubules?

Answer 15

Steroid-secreting cells (leydig cells), nurse cells (SERTOLI) , germ cells (spermatogonia)

Question 16

What direction does spermatogenesis go? (Towards or away from the lumen)

Answer 16

Towards the lumen

Question 17

What does the acrosome contain in the sperm?

Answer 17

Enzymes need to penetrate an ovum during fertilization

Question 18

What does the head of the sperm contain?

Answer 18

(Haploid) chromosomes

Question 19

What does the middle piece of the sperm contain?

Answer 19

Mitochondria that generates ATP to keep the tail moving