Lecture 10

Question 1

What are the 3 major fxns of male sex organs?

Answer 1

1. Spermatogenesis
2. Semen production
3. Maintenance of secondary sex characteristics and libido

Question 2

Compare and contrast female and male sex organ fxns

Answer 2

1. Male sex organs have ENDOCRINE (things that stay in body) and EXOCRINE (things that leave body) fxn vs. Females just endocrine
2. Males have no cyclicity (spermatogenesis starts n continues thruout life)
3. For both, Normal development and physiology are dependent on hormones

Question 3

Describe the fxn of the following:

1. Testes
2. Epididymis
3. Vas deferens
4. Seminal vesicle
5. Prostate
6. Prostatic urethra
7. Bulbous urethra
8. Penile urethra

Answer 3

1. Testes: site of sperm production
2. Epididymis: sperm maturation
3. Vas deferens: carries sperm from epididymis to urethra
4. Seminal vesicle: Provides sperm fluid, proteins, enzymes, fructose, prostaglandins, semenogelins
5. Prostate: Gives fluid containing citrate (metabolizes sperm), zinc *stabilization of DNA), PSA (alkaline and helps liquify sperm)
6. Prostatic urethra: bladder to bulbous urethra
7. Bulbous urethra:
8. Penile urethra:

Question 4

*Mutations in SRD5A2 result in _____ deficiency

Answer 4

5α-reductase 2

Question 5

Example of secondary sex characteristics

Answer 5

Penis, scrotum, prostate, seminal vesicles

Question 6

Describe the organization of testes: semifinerous tubules

Answer 6

1. Intratubular compartment: seminiferous epithelium (sperm cells and Sertoli cells)
2. Peritubular compartment: connective tissue, vascular tissue, immune cells, Leydig cells

Question 7

Describe primordial germ cell differentiation into spermatozoa

Answer 7

1. 1 Primordial germ cell (2N)

Enters gonad (migrates to testes during embryo formation)

2. 1 Spermatogonium (2N DNA)

First mitotic division begins at puberty – new cohorts enter the process every 16 days

3. 1 Spermatogonium 4N DNA

Mitosis

4. 2 Spermatognia (2N DNA)

Many rounds of mitosis

5. 4 spermatogonia (2N DNA)
6. 4 Primary spermatocyte (diploid 4N DNA)
   - Meiotic event: 1st meiotic division in progress
7. 8 secondary spermatocytes (haploid 2N DNA)
   - Meiotic event: second meiotic division in progress
8. 16 spermatids (haploid 1N DNA)
   - Meiotic event: Immature haploid gametes
9. Mature sperm (spermatozoa)
   - Meiotic event: Haploid gamets
   - 76 days from 1st mitotic division

Question 8

Fxn of sertoli cells in spermatogenesis

Answer 8

• support sperm formation

- form blood-testis barrier

Question 9

Describe Incomplete cytokinesis in spermatids (1N)

Answer 9

all daughter cells connected by cytoplasmic bridge -synchrony of clonal population of sperm cells

Question 10

Describe the parts of a spermatozoon

Answer 10

Head, middle piece, prinicipal piece, end piece

Question 11

What 3 criteria must be met for infertility

Answer 11

1. <20 million per ml
2. <50% motile
3. <60% normal morphology