Male Reproductive System

Question 1

What are the primary male reproductive organs?

Answer 1

Testes (male gonads)
Scrotum
Penis

Question 2

What are the accessory ducts in the male reproductive system?

Answer 2

Epididymis
Vas deferens
Ejaculatory duct
Urethra

Question 3

What are the accessory glands in the male reproductive system?

Answer 3

Prostate gland
Seminal glands
Bulbo-urethral glands

Question 4

What is the pathway that sperm follows to ejaculation?

Answer 4

Testes:

• semineferous tubules in lobules of testes
• rete testis

Epididymis

• efferent ductules
• head to body to tail

Vas deferens
- in spermatic cord in inguinal canal

Ejaculatory duct
- formed by union of vas deferens and seminal vesicles

Urethra
- prostatic, membranous, spongy

Question 5

What are the contents of the spermatic cord?

Answer 5

• the vas deferens
• lymphatic vessels
• the testicular, ductus deferens and cremasteric arteries
• the pampinform venous plexus
• the genitofermoral nerve, and SNS, PNS and visceral afferent nerves

Question 6

What are the components of the testes?

Answer 6

• each testes contains 250 lobules (divided by septa)
• each lobule contains 1-4 semineferous tubules (70cm long tubules, site of spermatogenesis)
• lobules feed into rete testis (tubular network on posterior aspect of testis, drains into epididymis)

Question 7

What are the layers of the testes?

Answer 7

Tunica albuginea (inner layer)

• tough fibrous inner capsule
• creates septa that divides testes into lobules

Tunica vaginalis (outer layer)

• develops from peritoneum
• visceral and parietal layers separated by peritoneal cavity

Question 8

What are the 4 different cell types in the testes?

Answer 8

Spermatogenic cells:

• produce 100 million sperm cells daily
• located in semineferous tubules

Sustentacular (Sertoli) cells:

• support spermatogenic cells
• nourish developing sperm

Interstitial endocrine (Leydig) cells:
- produce androgens (mostly testosterone)

Myoid cells:

• contract rhythmically
• squeeze sperm and fluids out of semineferous tubules

Question 9

Which cells are responsible for the production of sperm?

Answer 9

Spermatogenic cells (in the semineferous tubules in the testes) produce 100 million sperm cells daily

Question 10

What is the arterial and venous supply of the testes?

Answer 10

Arterial:
- testicular arteries (from abdo aorta L2)

Venous:

• pampinform plexus
• travels in spermatic cord
• drains into testicular veins

Question 11

What is the innervation of the testes?

Answer 11

SNS: T10-11
PNS: CNX Vagus
visceral afferent fibres

Question 12

What is the scrotum?

Answer 12

• an external outpouching of skin, fascia and muscle

- contains the testes, epididymis, and distal ends of spermatic cord

Question 13

What is the function of the scrotum?

Answer 13

• controls temperature of testes for optimum spermatogenesis (cools by 3 degrees)

Dartos & cremaster muscle:

• relaxation: promotes heat loss
• contraction: prevents heat loss

Question 14

What are the 6 layers of the scrotum?

Answer 14

(deep to superficial)

1. tunica vaginalis
   - from an outpouching of the vaginal process peritoneum
2. internal spermatic fascia
   - continuation of transversalis fascia
3. cremaster fascia
   - continuation of IO aponeurosis
4. cremaster muscle
   - originates from IO
   - raises testes
5. external spermatic fascia
   - continuation of EO aponeurosis
6. skin and superficial fascia
   - contains dartos muscle (wrinkles skin of scrotum)

Question 15

Which layers of the scrotum are continuations of the transversalis fascia, EO and IO?

Answer 15

• internal spermatic fascia = continuation of transversalis fascia
• cremaster fascia = continuation of IO aponeurosis
• cremaster muscle = originates from IO
• external spermatic fascia = continuation of EO aponeurosis

Question 16

What is the arterial and venous supply of the scrotum?

Answer 16

Arterial:

• scrotal arteries (from internal and external pudendal arteries)
• branches from testicular and cremasteric arteries

Venous:
- scrotal veins, draining into pudendal veins

Question 17

What is the lymphatic drainage of the scrotum and testes?

Answer 17

Scrotum:
- superficial inguinal lymph nodes

Testes:
- lumbar and pre-aortic nodes

Question 18

What is the innervation of the scrotum?

Answer 18

Anterior scrotal nerves:
- from ilioinguinal (L1) and genitofemoral (L1-2)

Posterior scrotal nerves:
- from superficial perineal (S2-3) and posterior femoral cutaneous (S2-3)

Question 19

What is the epididymis?

Answer 19

• a highly convuluted tubule (7m long) on posterior surface of testes
• has a head with efferent ductules, body and tail connecting to vas deferens
• connect rete testis to vas deferens
• sperm travel passively along tube over several days, maturing and becoming capable of fertilization
• epididymis stores sperm until ejaculation

Question 20

What is the vas deferens?

Answer 20

• a 45cm long muscular tube
• conveys sperm from epididymis to ejaculatory duct
• travels in spermatic cord through inguinal canal

Question 21

Which two structures combine to form the ejaculatory duct?

Answer 21

The vas deferens (conveying sperm) and the duct of the seminal vesicles (conveying seminal fluid)

• ejaculatory duct travels through posterior prostate and opens into prostatic urethra

Question 22

What are the seminal vesicles?

Answer 22

• paired glands on the posterior surface of the bladder
• secrete a thick fluid that mixes with sperm to form seminal fluid
• duct of each seminal vesicle joins with vas deferens to form ejaculatory duct

Question 23

What are the bulbourethral glands?

Answer 23

• paired pea size glands inferior to prostate gland
• each gland has a duct which passes through the perineal membrane with urethra and open into proximal part of spongy urethra in the bulb of the penis
• produce mucous like secretions into the urethra during sexual arousal
• secretions neutralize pH of urine residue in urethra and lubricate tip of penis

Question 24

What are the components of the penis?

Answer 24

Root:

• fixed to anterior pelvis
• consists of right and left crura and bulb

Crura:

• masses of erectile tissue (left and right)
• attach to ischial rami, and covered by ischiocavernosus mm
• converge to form paired corpora cavernosa in the shaft

Bulb:

• mass of erectile tissue in the midline
• continues as corpus spongiosum in the shaft
• outer surface covered by bulbospongiosus mm
• superior surface penetrated by urethra

Shaft:

• 3 cylindral columns of erectile tissue (corpus spongiosum in midline, 2 x corpus cavernosa laterally)
• corpus spongiosum in midline conveys spongy urethra
• contained within a fibrocartilaginous capsule

Glans:

• head of the penis
• expansion of corpus spongiosum
• external urethral orifice exits at tip of glans
• covered by a double layer of skin (prepuce / foreskin)
• corona of glans = crown of penis

Question 25

Which structures become the corpus spongiosum and corpus cavernosum in the shaft of the penis?

Answer 25

Corpus spongiosum (midline) from bulb of penis

Corpus cavernosa (paired laterally) from right and left crura

Question 26

What is the arterial and venous supply of the penis?

Answer 26

Arterial:
- branches of internal pudendal artery (from internal iliac artery)

Venous:

• cavernous spaces drain into venous plexus and deep dorsal vein of penis, then prostate venous plexus
• superficial coverings drain into superficial dorsal vein then external pudendal vein

Question 27

What is the nervous supply of the penis?

Answer 27

ANS:

• SNS: T12-L2
• PNS: pelvic splanchnic (S2-4)
• visceral afferents

Somatic sensory to most of penis; and motor supply to bulbospongiosus and ischiocavernosus:
- pudendal (S2-4) and dorsal nerve of penis (terminal nerve of pudendal)

Somatic sensory to root of penis:
- branches of ilioinguinal nerve (L1)