Semen Production + Spermatogenesis

Question 1

semen

Answer 1

thick whitish fluid

contains sperm + fluid from excessory glands

Question 2

semen components (6)

Answer 2

• fructose (fuel for sperm)
• prostaglandins (facilitate sperm movement)
• relaxin (increases sperm motility)
• alkaline pH (protects sperm from leftover acidic urine in urethra)
• antibiotic (kills bacteria)
• 200-500 million sperm

Question 3

glands providing fluid for semen (3)

Answer 3

1. seminal vesicles
2. prostate gland
3. bulbourethral glands

Question 4

seminal vesicles

Answer 4

• paired glands at base of bladder

- as sperm passes, secrete thick viscous fluid containing nutrients for sperm

Question 5

prostate gland

Answer 5

• just below bladder

- secretes thin milky alkaline fluid to increase motility of sperm

Question 6

bulbourethral glands

Answer 6

• on both sides of urethra below prostate

- produce first secretion of ejaculation: alkaline fluid that neutralizes acidity of any urine in urethra

Question 7

spermatogenesis overview

Answer 7

• production of sperm
• takes 64-72 days to complete
• begins at puberty, continues throughout lifetime

Question 8

process of sperm formation

Answer 8

1. at puberty, ant. pit. gland releases FSH, which causes spermatogonia to divide
2. each spermatogonia splits into stem cell (spermotagonia) + primary spermacyte
3. primary spermocyte undergoes myosis to produce 4 spermatids (gametes)
4. each spermatid contains 23 chromosomes and will be viable sperm after spermiogenesis

Question 9

spermatogonia

Answer 9

• stem cells (46 chromosomes each) located in testes’ seminiferous tubules
• undergo mitotic division from birth until puberty

Question 10

spermiogenesis

Answer 10

• final phase of spermatogenesis

- cytoplasm of spermatid is stripped away to produce mature sperm

Question 11

3 parts of sperm

Answer 11

1. head
2. midpiece
3. tail

Question 12

head of sperm

Answer 12

made up of nucleus (with all DNA) and acromosome

Question 13

midpiece of sperm

Answer 13

• contains mitochondria

- mitochondria generate the tremendous locomotive energy from sperm to swim all the way to the ovum

Question 14

tail of sperm

Answer 14

• typical flagellum

- propels sperm through female reproductive tract

Question 15

acromosome

Answer 15

crown on head of sperm containing enzymes that break down egg cell’s membrane