Male Reproductive System

Question 1

Testes

Answer 1

• Site of spermatozoa production
• Descend from posterior abdominal wall to the scrotum with the aid of gubernaculum
• Situated external to body because lower temperatures are required for sperm production

Arterial supply:

1) Testicular artery
2) Artery of vas deferens
3) Cremasteric artery

Venous:

1) Pampiniform plexus
- Right testicular vein drains into IVC
- Left testicular vein drains into left renal vein

Lymphatics:
-Para-aortic nodes

Question 2

Cryptorchidism

Answer 2

• Arrest of descend of testis from posterior abdominal wall to scrotum
• Can lead to:
  1) Maglinancy
  2) Infertility

Question 3

Route of Sperm

Answer 3

1) Production at semiferous tubule
2) Collects at rete testis via tubules
3) Stored and mature at epididymis
4) Pass into vas deferens

Question 4

Epididymis

Answer 4

• 4cm long (6m long uncoiled)
• Function:
  1) Site of maturation and storage of sperm

Question 5

Vas deferens

Answer 5

-Contained within spermatic cord and transverse inguinal canal and terminates at ampulla of vas deferens

Question 6

Seminal vesicle

Answer 6

• Contribute 70% of fluid to ejaculate
• Contains:
  1) Alkaline fluid
  2) Fructose
  3) Prostaglandins
  4) Clotting factors

Question 7

Ejaculatory duct

Answer 7

• Formed by the union of vas deferens and seminal vesicle

- Projects into prostatic urethra

Question 8

Spermatic cord

Answer 8

Contents:

1) Vas deferens
2) Lymphatics
3) Tunica vaginalis
4) Testicular artery
5) cremasteric artery
6) Artery of vas deferens
7) Pampiniform plexus
8) Autonomic nerves (sympathetic + parasympathetic)
9) Genital branch of ilioinguinal nerve

Question 9

Prostate gland

Answer 9

• Located at base of bladder
• Contributes to 30% of fluid in ejaculate (sperm have better mobility, better survival and protection)

Can be divided into:

1) Central zone (20% of volume)
- encloses ejaculatory duct
2) Transition zone (5% of volume)
- Encloses urethra
- Benign prostate hyperplasia (BPH) occurs in this zone
3) Peripheral zone (75% of volume)
- this area is felt during Digital Rectal Examination (DRE)
- Prostate cancer usually occurs in this zone

Question 10

Bulbourethral gland (aka Cowper’s gland)

Answer 10

• Contribute to a small amount of ejaculate

- Opens into membranous prostate

Question 11

Urethra

Answer 11

-15-20cm long
Can be divided into:
1) Pre-prostatic (1 cm)
2) Prostatic (3-4 cm)
3) Membranous (1 cm) -- LEAST DILATABLE (easily injured during catheterization)
4) Penile/Spongy (15-20 cm)

Question 12

Seminal colliculus

Answer 12

• Prominent portion of urethral crest
• Contains:
  1) Prostatic utricle (remnant of paramesonephric ducts)
  2) Openings of ejaculatory ducts

Question 13

Erectile tissue of penis

Answer 13

1) Root of penis –> left and right crus give rise to corpus cavernosum of body of penis
2) Bulb of penis –> give rise to corpus spongiosum (expands to give rise to glans penis)

Arterial supply (all branches of internal pudendal artery):

1) Dorsal arteries (x2)
2) Deep arteries (x2) (within corpus cavernosum)
3) Bulbourethral artery (within corpus spongiosum)

Neurological control:

• Parasympathetic – release of NO act on muscarinic receptors to cause dilation of corpus cavernosum and allow it to fill with blood causing an erection
• Sympathetic – cause ejaculation

Question 14

Pouch

Answer 14

Rectovesical pouch (located between bladder and rectum)

Question 15

Scrotum

Answer 15

-Dartos muscle underneath skin layer –> regulation of temperature of scrotum by wrinkling skin (decrease SA and decrease heat loss)

Arterial supply:
1) Anterior and posterior scrotal arteries

Lymphatics:
-Superficial inguinal nodes