Spermatogenisis And Sperm Maturation

Question 1

Spermatogenesis

Answer 1

Spermatozoa are produced in the testis

Question 2

What do testsis produce

Answer 2

Hormones and spermatozoa

Question 3

What is the tunica albuginea?

Answer 3

White fibrous capsule

septa divide the organ into compartments containing
seminiferous tubules where sperm are produced and meiosis occurs

Question 4

Leydig cells

Answer 4

clusters of cells between the seminiferous tubules and source of testosterone

Question 5

Sertoli cells promote sperm cell development

Answer 5

blood-testis barrier is formed by tight junctions between
sertoli cells; separating sperm from immune system

Seminiferous tubules drain into network called rete testis

Question 6

Why is thermoregulation of testis necessary?

Answer 6

As sperm are not produced at core body temperature

Question 7

Heat exchange of pampinfiomr plexus

Question 8

Spermatogenisis produces 2 types of daughter cells

Answer 8

• type A spermatagoonia remain outside blood-testis barrier & produce more
  daughter cells until death
  – type B differentiate into primary spermatocytes-Type B is still diploid
  • cells must pass through Blood testis barrier to move inward toward lumen - new tight junctions form behind these cells
  • meiosis I leads to 2 secondary spermatocytes
  • meiosis II leads to 4 spermatids

Question 9

How are spermatids transformed to spermatozoa?

Answer 9

Through the process of spermoiogenisis

sprouts tail and discards cytoplasm to become lighter

Question 10

Process of spermatogenesis produces

Answer 10

300 to 600 sperm are made per gram of testis per second

-50g x 50 min x 60 sec x 500 sperm = 75,000,000 spermatozoa

Question 11

Sertoli cells are important in spermatogenisis

Answer 11

Blood-testis barrier is formed by tight junctions between and basement membrane under sertoli cells.

Question 12

Efferent ductules

Answer 12

12 small ciliated ducts collecting sperm from the rete testes and transporting it to the epididymis

Question 13

Epididymis (head body and tail)

Answer 13

site of sperm maturation & storage (fertile for 40 to 60 days)

Question 14

Ductus vas deferens

Answer 14

– musculartube45cmlongpassingup from scrotum through inguinal canal to posterior surface of bladder
– widens into a terminal ampulla

Question 15

Ejaculatory duct

Answer 15

– 2 cm duct formed from ductus deferens & seminal vesicle & passing through prostate to empty into urethra

Question 16

Accessory glands

Answer 16

Seminal vesicles

Prostate gland

Bulbourethral glands

Question 17

Semen come froms

Answer 17

60% seminal vesicle fluid, 30% prostatic & 10% sperm and trace of bulbourethral fluid

Question 18

2-5 mL of fluid expelled during orgasm

Answer 18

sperm serve to digest path through cervical mucus and to fertilize egg

Question 19

Components of semen

Answer 19

– fructose provide energy for sperm motility
– fibrinogen
– clotting enzymes convert fibrinogen to fibrin causing semen to clot
– fibrinolysin liquefies semen within 30 minutes
– prostaglandins stimulate female peristaltic contractions
– spermine is a base stabilizing sperm pH at 7.2 to 7.6

Question 20

Role of sex chromosomes

Answer 20

contain 23 pairs of chromosomes
– 22 pairs of autosomes
– 1 pair of sex chromosomes (XY males: XX females) • males produce 50% Y carrying sperm and 50% X carrying • all eggs carry the X chromosome
• Sex of the child is determined by the type of sperm that fertilizes the mother’s egg