2C. Reproduction - Males

Question 1

What are the roles of the males in the reproductive system?

Answer 1

• Provide half the genetic material to offspring
• Deliver the genetic material to the right part of the female reproductive tract

Question 2

What is the primary sex organ in males?

Answer 2

Testes
- Divided into lobes
- Produce spermatozoa that are produced in seminiferous tubules (spermatogensis)
- Leydig cells (interstitial) produce testosterone

Question 3

Why is testicular temperature important?

Answer 3

• To produce viable, fertile sperm
• Must be below body temperature

Question 4

What is cryptoorchid?

Answer 4

• An animal that has not had his testes descend into the scrotum
• Infertile sperm since it’s at body temp

Question 5

How is testicular temperature maintained? (3)

Answer 5

1. Cremaster and tunica dartos muscles: pull the scrotum up and down to regulate temperature
2. Sweat glands: help cool it down by increasing the amount of evaporative heat loss
3. Specialized blood supply: allows for heat loss, the blood flowing to the testes is cooled before it arrives by a counter current heat exchange system

Question 6

What is the paminiform plexus?

Answer 6

A loose network of small veins found within the male spermatic cord

Question 7

What are the accessory organs in males? (5)

Answer 7

1. Epididymus
2. Scrotum
3. Vas deferens
4. Accessory glands
5. Penis

Question 8

Answer 8

Question 9

What is the function of the epididymis?

Answer 9

1. TRANSPORT sperm from seminiferous tubules to vas deferens
2. CONCENTRATE sperm during the movement from head to tail of epididymis
3. MATURATION of sperm
4. STORAGE of sperm for 60 days it stays fertile

Question 10

What is the function of the vas deferens?

Answer 10

TRANSPORT sperm from epididymis to urethra

Question 11

What are the accessory glands?

Answer 11

1. Vesticular
2. Prostate
3. Bulbourethral glands (cowpers)

Question 12

What is the function of vesicular glands?

Answer 12

• FLUID, BUFFER AND NUTRIENTS for ejculate
• In bulls, contribures more than half of the fluid

Question 13

What is the function of the prostate gland?

Answer 13

• Source of inorganic ions in a small amount of fluid
• In boars it contributes alot of fluid

Question 14

What is the function of the bulbourethral glands?

Answer 14

AKA cowpers gland
In bulls: flushes any urine residue in the urethra
In boars: portion of semen that coagulates so that semen does not flow back into the vagina from the cervix

Question 15

What is the function of sigmoid flexure?

Answer 15

• S-shape in the penis that retracts the penis into the sheath for protection

Question 16

What is the function of the penis?

Answer 16

• Organ of copulation
• Deposits sperm into female

Question 17

What is capacitation?

Answer 17

• Sperm must go through this before it fertilizes an egg
• Full maturation of sperm
• Happens in the female repro. tract

Question 18

Which animal does sperm remain fertile in the female for the longest/shortest?

Answer 18

L: poultry
S: cows and ewes

Question 19

What are the hormones found in the male reproductive system, where are they found and their function (4)

Answer 19

1. GnRH - hypothalamus - at puberty it releases FSH and LH
2. LH - pituitary - stimulate leydig cells to produce testosterone
3. Testosterone - testis - stimulates production of sperm
4. FSH - pituitary - enters the seminiferous tubules and stimulates sertoli cells to further develop the sperm cells

Question 20

What is the general function of hormones in secondary sex characteristics

Answer 20

• Responsible for development of male characteristics at puberty
• Testosterone: increased skeletal muscle, reproductive tract, secondary sex characteristics and libido

Question 21

How often does the cyclic episodes occur and what does it do?

Answer 21

• 4-6 hours
• continuous development of sperm