Male Reproductive System

Question 1

What is hemizygous?

Answer 1

• one copy of x-chromosome
• what males are
• b/c male only have one x-chromosome copy they are more likely to express a disease-causing allele in the unpaired part of the x-chromosome compared to females

Question 2

What is the Y chromosome?

Answer 2

• contains little genetic information

- contains the SRY chromosome

Question 3

What is SRY?

Answer 3

• sex-determining region Y

- codes for a transcription factor that initiates testis differentiation and formation of male gonads

Question 4

What are testes?

Answer 4

• produces and store sperm
• main source of testosterone
• contain 2 functional components – seminiferous tubules and interstital cells of leydig

Question 5

Where is sperm produced?

Answer 5

seminiferous tubules

Question 6

What cells nourish sperm?

Answer 6

sertoli cells (located in seminiferous tubules)

Question 7

What do the cells of leydig secrete?

Answer 7

• testosterone

- androgens

Question 8

What is the function of the scrotum?

Answer 8

maintains a temperature 2-4 degrees celsius lower than body temperature

Question 9

What is the epididymis?

Answer 9

• where sperm flagella gain motility

- where sperm are stored until ejaculation

Question 10

What is seminal fluid?

Answer 10

• mixed with sperm

- produced through combined effort by seminal vesicles, prostrate gland, and bulbourethral gland

Question 11

What is the function of seminal vesicles?

Answer 11

contribute fructose to nourish sperm and mildly alkaline properties

Question 12

What is the function of the prostrate gland?

Answer 12

gives sperm mildly alkaline properties so that is can survive the relative acidity of the female reproductive tract

Question 13

What is the function of the bulbourethral gland?

Answer 13

produces fluid that cleans out urine reminants and lubricates urethra during sexual arousal

Question 14

What is semen made of?

Answer 14

sperm and seminal fluid

Question 15

What is the pathway of sperm through the reproductive system?

Answer 15

SEVE(N) UP

1. Seminiferous tubules
2. Epididymis
3. Vas deferens
4. Ejaculatory duct
5. Urethra
6. Penis

Question 16

What is spermatogenesis?

Answer 16

• the formation of haploid sperm through meiosis
• occurs in the seminiferous tubules
• results in 4 functional sperm/spermatogonium

Question 17

Spermatogonia

Answer 17

• diploid sperm cells

- form present before replication (S stage)

Question 18

Primary Spermatocyte

Answer 18

• product after replication (S stage)

- one diploid sperm cell

Question 19

Secondary Spermatocyte

Answer 19

• product after first meiotic division

- two haploid daughter cells

Question 20

Spermatids

Answer 20

• product after second meiotic division

- 4 haploid daughter cells

Question 21

Spermatozoa

Answer 21

mature spermatids

Question 22

Timeline of male sexual development

Answer 22

1. Fetal period (9 wks after fertilization - birth): presence of Y chromosome leads to androgen production resulting in male sexual differentiation
2. Infancy and Childhood: low androgen production
3. Puberty: increase in testosterone production by testes, sperm production starts
4. Adulthood: high testosterone levels that decline in old age

Question 23

What is the role of FSH?

Answer 23

stimulates sertoli cells which leads to sperm maturation

Question 24

What is the role of LH?

Answer 24

causes interstitial cells to produce testosterone

Question 25

Describe the head of mature sperm

Answer 25

• contains genetic material
• covered by a cap called the acrosome (derived from golgi apparatus and necessary to penetrate the ovum)
• contains nucleus and plasma membrane

Question 26

Describe the midpiece of mature sperm

Answer 26

filled with mitochondria to generate ATP that is used as the sperm swims to the ovum in the fallopian tubes

Question 27

Describe the tail of mature sperm

Answer 27

flagellum used for motility