Reproduction - Male

Question 1

What is it called when the testes are undescended?

Answer 1

Cryptorchisism

Question 2

What are the mechanisms for temperature regulation of the testes?

Answer 2

• sweat glands
• cremaster muscle can adjust the position of the testes
• pampiniform plexus - network of blood vessels within the spermatic cord, responsible for blood supply of the testes. Heat exchange occurs between testicular artery and pampiniform plexus, some heat from the artery is transferred and taken away by the veins

Question 3

Where does sperm finish maturing?

Answer 3

Epididymis

Question 4

What is the function of the epididymis?

Answer 4

Sperm maturation (gain mobility, metabolic changes, cell membrane changes), storage and transport

Question 5

What are the characteristics of the epididymis?

Answer 5

• single, highly coiled tube

- 2-6 day passage

Question 6

What is the ejaculatory duct?

Answer 6

Transition between vas deferens and urethra

Question 7

Bulbourethral gland

Answer 7

• paired glands
• less than 5% seminal fluid
• alkaline (neutralises environment in urethra)
• pre-ejaculatory fluid

Question 8

Seminal vesicles

Answer 8

• paired glands
• 65% of seminal fluid
• alkaline (neutralises environment in vagina)
• contains prostaglandin clotting proteins - prevent sperm from falling out of female, protections against acidic environment and fructose (fuel source for flagellum)

Question 9

Prostate

Answer 9

• single Gland
• 30% of seminal fluid
• liquefying protein - counteract prostaglandins

Question 10

What are the three bodies of erectile tissue?

Answer 10

Two larger: Corpus cavemosum

One smaller: Corpus spongiosum

Question 11

What happens in an erection?

Answer 11

More blood entering than leaving

Question 12

What does the Corpus spongiosum do?

Answer 12

Maintains urethra so that is doesn’t close enabling sperm and ejaculate to exit

Question 13

What is capacitation?

Answer 13

• sperm attain their fertilising capacity

- occurs in the uterus or uterine tube due to estrogen

Question 14

What is capacitation characterised by?

Answer 14

• change in motility (hyperactive tail, more vigorous movement)
• change in cell surface membrane (activation of enzymes which are designed to burrow into and digest the binding matrix of cumulus cells)

Question 15

What is the acrosome reaction?

Answer 15

• sperm encounters the egg

- exocytosis of the acrosome, releasing the enzymes needed to penetrate the egg

Question 16

What happens after the acrosome reaction?

Answer 16

Chain of events that prohibits polysoermy

Question 17

Why is the first sperm to reach the egg not the one to fertilise it?

Answer 17

• sperm must first penetrate the cumulus cells and zona pellucida that surround it
• it may require hundreds of sperm to clear a path for the on sperm that penetrates the egg

Question 18

What occurs in spermiogenesis?

Answer 18

• Golgi forms acrosomal vesicle and then acrosome which covers the head of the sperm
• nucleus condenses
• distal centriole migrates out to membrane and forms the flagellum, mitochondria migrate to proximal part of flagellum
• cytoplasm ejected as a residual body