Male Genital Tract

Question 1

Primary male sex organs (gonads)

Answer 1

• testes
• produce sperm

Question 2

Urethra

Answer 2

• expels semen

Question 3

Testis

Answer 3

• where sperm are produced

Question 4

Epididymus

Answer 4

• where sperm mature

Question 5

Ductus Deferens

Answer 5

• transports sperm to urethra

Question 6

Bulbourethral gland

Answer 6

• produces alkaline, mucus-rich fluid to help neutralize urethral environment

Question 7

Prostate gland

Answer 7

• produces enzyme-rich component of semen
• surrounds prostatic part of urethra

Question 8

Seminal vesicle

Answer 8

• produces fructose-rich component of semen
• found behind bladder
• join with ampulla of ductus deferens to form ejaculatory duct

Question 9

Testes are housed where?

Answer 9

• scrotum (external sac, outside body cavity), divided into two compartments by septum
• septum of scrotum = CT
• septum of scrotum and scrotum = not a part of penis

Question 10

Cremaster muscle

Answer 10

• contracts to elevate testis and maintain optimal temperature for sperm development (~ 3 degrees cooler than body temp)

Question 11

The penis is composed of what?

Answer 11

• penis composed of 3 erectile bodies
  > unpaired corpus spongiosum (1)
  > paired corpora cavernosa (2)

Question 12

What are the 3 regions of the penis?

Answer 12

• the root of the penis is the base — where it attaches to the pelvis
• the body of the penis = free portion
• glans penis = enlarged end
• prepuce (foreskin)

Question 13

Prostatic urethra

Answer 13

• passes through prostate

Question 14

Membranous urethra

Answer 14

• passes through perineal muscles
• short

Question 15

Penile urethra

Answer 15

• passes through corpus spongiosum of penis
• also called spongy urethra

Question 16

Descent of testes

Answer 16

• descends from abdominal cavity
• through in inguinal canal (deep inguinal right + superficial inguinal ring)
• into scrotum
• guided by gubernaculum
• cryptochidism = failure of testes to descend

Question 17

Spermatic cord

Answer 17

• weak spot in abdominal wall
• spermatic cord = ductus deferens, fascia, testicular vessels (testicular artery & pampiniform plexus) nerves
• extends from scrotum to inguinal canal
• medial opening = superficial inguinal ring
• deep inguinal ring = where ductus deferens and testicular vessels enter abdomen

Question 18

What do the testes produce and what are they divided into?

Answer 18

• produce sperm (by tubules) and androgens (by supporting cells)
• divided by connective tissue septa into lobules containing:
  > seminiferous tubules
  > straight tubule
  > rate testis
  > efferent ducts

Question 19

Interstitial cells

Answer 19

• lie outside of CT capsule; produce androgens in response to Luteinizing hormone which begins process of spermatogenesis

Question 20

Production of Spermatozoa — 1st step

Answer 20

• spermatogonium: deep to blood-testis barrier
• immature sperm cells

Question 21

Production of Spermatozoa — 2nd step

Answer 21

Spermatids: in various stages of maturation

Question 22

Nurse cells

Answer 22

• provide physical support for maturing spermatogonium
• make up stuff spermatogonium sits in

Question 23

Production of Spermatozoa — 3rd step

Answer 23

• getting ready for spermination
• mature sperm cell, but not quite activated yet

Question 24

The epididymus

Answer 24

• where we go after producing spermatozoa
• 1. Head of epididymus (receiving things straight from rete testis)
• 2. Body of epididymus
• 3. Tail of epididymus
• 4. Ductus deferens (will deliver us to the urethra)
• site of sperm maturation and storage: protein secretions nourish sperm and help maturation

Question 25

What does the epididymus do during ejaculation?

Answer 25

• smooth muscle in walls of epididymus contract, expel sperm into ductus deferens

Question 26

Spermatozoa

Answer 26

• tail: flagellum —> self propelled
• middle: mitochondria—> gives it energy
• head: acrosomal cap (needs to dissolve for it to mature) and genetic material (in the cap)

Question 27

Spermatogenesis

Answer 27

• production of spermatic (1n gamete) from spermatogonia (2n gamete)
• occurs in seminiferous tubules
  -begins during embryonic development; dormant until sexual maturity
• spermatogonium —>spermatid —>spermatozoa
• direct stimulation by follicle-stimulating hormones
• indirect by androgens

Question 28

Accessory glands picture

Answer 28

Question 29

Production of semen

Answer 29

• Sperm production in seminiferous tubules
• Sperm storage and maturation in epididymis
• Sperm travel through ductus deferens
• Seminal fluid and sperm come together in ejaculatory duct
• Prostatic fluid added to fluid in prostatic urethra
• Sperm travel through membranous and spongy urethra
• Sperm reach outside world (through external urethral orifice)

Question 30

Stimulation and Erection

Answer 30

• pudendal nerve: provides sensory input from genitals to CNS
• parasympathetic nerves cause relaxation of arterial smooth muscle in erectile bodies and secretion from greater vestibular glands/bulbourethral glands
• Erectile bodies become engorged with blood due to relaxation of arterial smooth muscle (parasympathetic)
• Veins get compressed due to increased blood in erectile body
• Perineal muscles contract, raising pressure in the erectile bodies even more

Question 31

Orgasm

Answer 31

• somatic response: rhythmic contraction of pelvic and perineal muscles
• sympathetic response:
  > Emission: peristalsis of ductus deferens delivers semen to the prostatic urethra
  >Remission/Detumescence: Constriction of arterial vessels