PSIO202 Exam 4 - Male Repro

Question 1

Describe the internal anatomy of a testis.

Answer 1

Outer layer called the tunica vaginalis, followed by the tunica albuginea. Inside are the seminiferous tubules (with septums between each group), straight tubules, the rete testis, and efferent ducts which take sperm to the epididymis. The epididymis moves into the ductus (vas) deferens.

Question 2

Where are Sertoli cells located, and what do they do?

Answer 2

Within the epithelial layer of the seminiferous tubule (in the testes). They extend from the basal lamina to the lumen, and are columnar with adjoining processes.
- nurse cells
- support the production and development of sperm

Question 3

Where are Leydig cells and what do they do?

Answer 3

in the little triangles of connective tissue between the loops of the seminiferous tubules
- produce testosterone

Question 4

What is spermatogenesis?

Answer 4

conversion of undifferentiated germ cells (spermatogonia) into specialized, motile sperm (spermatozoa)

Question 5

When a spermatogonium is first split during mitosis, what does each resulting cell become?

Answer 5

1 becomes a primary spermatocyte and continues throughout meiosis, and the other remains as a precursor stem cell

Question 6

What happens to the number of sperm stem cells through the process of mitosis?

Answer 6

it stays the same

Question 7

Meiosis 1 converts (#) ——- to (#) ——–.

Answer 7

1 primary spermatocyte to 2 secondary spermatocytes

Question 8

Meiosis 2 converts (#) ——- to (#) ——–.

Answer 8

2 secondary spermatocytes to 4 spermatids

Question 9

Overall, meiosis has —- round(s) of division and produces (#) haploid/diploid spermatids.

Answer 9

2 rounds of division
4 haploid spermatids

Question 10

How many chromosomes are in a gamete?

Answer 10

23 (1 copy of each of the 22 autosomes, and 1 X or Y sex chromosome)

Question 11

What is spermiation?

Answer 11

release of mature spermatozoa from the Sertoli cells into the lumen of the seminiferous tubule

Question 12

What is capacitation?

Answer 12

final maturation of the sperm that occurs within the female reproductive tract by secretions from the uterus

Question 13

What is spermiogenesis?

Answer 13

differentiation of spermatids into sperm via morphological changes that allow for motility and protection of the chromosomes from environmental changes

Question 14

What are the parts of a mature sperm and what is their basic purpose?

Answer 14

acrosome - facilitate penetration of a secondary oocyte
nucleus - contains the 23 chromosomes
middle piece/mitochondrial sheath - provides ATP for locomotion
tail - propels sperm through the female reproductive tract

Question 15

What occurs during capacitation?

Answer 15

• increase progesterone acting on the sperm
• Ca2+ influx through a progesterone binding Ca2+ channel
• hyperactivation triggered
• ability to penetrate the matrix around the oocyte

Question 16

What happens when a man is deficient in the progesterone-binding Ca2+ channel (CATSPER1 null)?

Answer 16

they are infertile

Question 17

How is male gamete formation controlled by hormones? Start at the hypothalamus, all the way to the cells effected.

Answer 17

increase GnRH (hypothalamus) triggers increased LH and FSH (anterior pituitary)

LH stimulates testosterone production from he Leydig cells. Testosterone stimulates the final steps of spermatogenesis and inhibits LH release.

FSH acts on Sertoli cells to promote spermatogenesis (by stimulating ABP, which keeps local testosterone high). Sertoli cells also release inhibin which reduces FSH release.

Question 18

What male reproductive ducts are important for TRANSPORT ONLY?

Answer 18

ejaculatory duct, prostatic urethra, membranous urethra, spongy urethra

Question 19

What male reproductive ducts are important for MATURATION AND STORAGE and TRANSPORT AND STORAGE?

Answer 19

maturation and storage: epididymis
transport and storage: ductus (vas) deferens and ampulla of the ductus deferens

Question 20

What are the three types of accessory glands of the male reproductive system?

Answer 20

seminal vesicles, prostate, and bulbourethral glands

Question 21

What is the role of the seminal vesicles?

Answer 21

contribute 60% of semen

produce viscous seminal fluid containing:
fructose - fuel for glycolysis for ATP production
prostaglandins - sperm viability motility, and transport
fibrinogen - coagulation of semen in the female reproductive tract

Question 22

What is the role of the prostate?

Answer 22

contribute 25% of semen

thin seminal fluid containing:
slightly acidic pH - citric acid used for ATP production
proteolytic enzymes - break down clotting proteins from the seminal vesicles
seminalplasmin - antibiotic that destroys bacteria

Question 23

What is the role of the bulbourethral/Cowper’s glands?

Answer 23

contribute 15% of semen

mucous-like fluid containing:
mucous - minimize damage to sperm during ejaculation
alkaline pH - protect sperm from acids in the urine

Question 24

What are the stimulus, pathways, and effectors of the erection reflex?

Answer 24

stimulus - receptors on the glans
pathway - sensory nerve of the pudendal nerve carries to the CNS (spinal cord, not brain)
effectors: smooth muscle of the cavernosa, bulbospongiosus muscle, and Cowper’s glands

Question 25

What happens to each of the effectors during the erection reflex?

Answer 25

smooth muscle of the cavernosus - nitrous oxide release relaxes the muscles and causes vasodilation
bulbospongiosus muscle - contracts around the veins to reduce blood flow out, maintaining the erection
Cowper’s glands - produce mucous and an alkaline pH to protect the sperm