Male Reproductive System

Question 1

components of male reproductive system

Answer 1

testes
duct system
glands
external genitalia
    -penis
    -scrotum

Question 2

testes

Answer 2

• male gonads
• contain seminiferous tubules where sperm is produced
• contain leydig cells where testosterone is produced

Question 3

contents of seminiferous tubules

Answer 3

• spermatogonia: sperm stem cells
• sperm
• sertoli cells
• leydig cells: *interstitial cell (not necessarily part of tubule)

Question 4

what is spermatogenesis?

Answer 4

the continuous process of sperm production
-begins at puberty
-continues into old age
process begins in outermost layer of seminiferous tubules
proceeds toward lumen in which sperm are released into

Question 5

steps in spermatogenesis

Answer 5

1. spermatogonia: undergo mitosis
2. spermatocytes: undergo meiosis
3. spermatids: undergo physical maturation
4. spermatozoa (aka sperm): enter lumen of seminiferous tubules

Question 6

three parts of a sperm

Answer 6

1. tail
2. middle piece
3. head

Question 7

head of mature sperm

Answer 7

• contains nucleus which contains chromosomes
• no energy reserves so have to absorb nutrients from surrounding fluid
• tip of head covered by acrosomal cap (essential for fertilization)

Question 8

middle pieces of mature sperm

Answer 8

contains mitochondria to provide energy ATP to move the tail

Question 9

tail of mature sperm

Answer 9

• only flagellum in human body

- whip-like organelle to move the cell

Question 10

functions of sertoli cells inside of seminiferous tubules

Answer 10

1. support spermatogenesis
   
   • provide nutrients and chemical stimuli for development
   • stimulated by FSH and testosterone
2. maintain blood-testis barrier
   
   • formed by tight junctions between sertoli cells

Question 11

leydig cells

Answer 11

• not inside of tubules
• in CT surrounding seminiferous tubules
• stimulated by LH to PRODUCE TESTOSTERONE

Question 12

functions of testosterone: male sex hormone

Answer 12

• most important androgen
  1. stimulates spermatogenesis
  2. promotes labida (sexual drive)
  3. establishes male secondary characteristics
  
  • facial hair and incr. muscle mass
    
    4. maintains glands and organs of male reproductive tract

Question 13

hormone regulation of FSH

Answer 13

FSH -> sertoli cells -> spermatogenesis -> sperm cells

Question 14

hormone regulation of LH

Answer 14

LH -> leydig cells -> testosterone -> sertoli cells, spermatogenesis, and reproductive tract

Question 15

semen =

Answer 15

sperm (from testes) + fluids (from glands)

-delivered by duct system

Question 16

pathway of spermatozoa thru duct system

Answer 16

1. epididymis
2. ductus deferens
3. ejaculatory duct
4. urethra

Question 17

epididymis

Answer 17

• coiled tube of duct system
• primary storage of sperms (protects them)
• sperm leaving here are still immobile

Question 18

ductus deferens

Answer 18

• tube of duct system
• stores sperm
• contains smooth muscle; contractions propel semen
• travels thru inguinal canal as part of spermatic cord

Question 19

spermatic cord

Answer 19

name for all of these:

• ductus deferens
• nerves
• blood vessels
• surrounding layer of anterior body wall including muscles and CT

Question 20

inguinal ligament and canal

Answer 20

• ligament forms canal
• passageway out of abdominal wall thru which spermatic cord must pass
• weak point in abdominal wall

Question 21

ejaculatory duct

Answer 21

• short duct formed by joining of ductus deferens and seminal vesicle
• travels thru prostate gland
• empties into urethra

Question 22

male urethra

Answer 22

• 1st part of it travels thru prostate gland which secretes prostate fluids into urethra
• then travels thru penis which releases semen

Question 23

glands

Answer 23

• produce the fluid component of semen
• includes:
  
  1. seminal vesicle
  2. prostate gland
  3. bulbourethral glands

Question 24

seminal vesicles

Answer 24

• produce most (60%) of semen volume

- its fluids activate immobile sperm

Question 25

semen fluid contains:

Answer 25

- fructose: energy - prostaglandins: stimulates muscle contractions - fibrinogen: forms temporary clot in vagina

Question 26

prostate gland

Answer 26

- encircles first part of urethra - forms 20-30% of semen volume - contains antibiotics

Question 27

penis

Answer 27

- releases urine and sperm - shaft is composed of erectile tissue - 2 corpa cavernosa which surrounds central artery - 1 corpus spongiosum which surrounds urethra

Question 28

scrotum

Answer 28

- divided into 2 chambers by scrotal septum - associated with 2 muscle types: 1. outer Dartos 2. inner Cremaster

Question 29

dartos muscle

Answer 29

-layer of smooth muscle in scrotum skin

Question 30

cremaster muscle

Answer 30

- layer of skeletal muscle deep to scrotum skin - component of spermatic cord - important for temperature regulation by moving testes away/towards body

Question 31

male sexual arousal

Answer 31

- initiates secretion of bulbourethral glands - leads to: 1. erection (parasympathetic) 2. emission (sympathetic) 3. ejaculation (somatomotor) * in this order*

Question 32

erection

Answer 32

1. bloodflow from arteries into erectile tissue increases 2. pressure exerted on connective tissue sheath collapses the dorsal vein, which prohibits drainage of blood out 3. penis stiffens

Question 33

emission

Answer 33

1. peristaltic contractions of smooth muscle in the ductus deferens, seminal vesicles, and prostate gland 2. this pushes semen into urethra

Question 34

ejaculation

Answer 34

1. rhythmic contractions of skeletal muscles surrounding erectile tissue in penis 2. this pushes semen out of urethral opening - accompanied by orgasm