Lecture 21: Male Reproductive System

Question 0

Remainder of mesonephric duct becomes?

Answer 0

the ductus (Vas) deferens and ejaculatory duct.

Question 1

The proximal mesonephric duct in a embryo becomes what?

Answer 1

epididymis

Question 2

Maculinisation of external genitalia ONLY in presence of?

Answer 2

testosterone

Question 3

Testicular descent: 7 months: testosterone stimulates?

Answer 3

descent of testes from pelvis to scrotum.

Question 4

Testicular descent:

Descent guided by what?

Answer 4

gubernaculum extending from testis to floor of scrotal sac.

Question 5

Testicular descent:

Drags supplying blood vessels and nerves along behind, this forms what?

Answer 5

spermatic cord

Question 6

The penis is made up of three major structures, what are these?

Answer 6

• Root (crura, bulb, ischiocavernosus and bulbospongiosus
muscles)
• Body.
• Glans.

Question 7

The penis has three cylinders of cavernous tissue, what are these?

Answer 7

2x corpora cavernosa (dorsal*)

1x corpus spongiosum (ventral*).

Question 8

What is the blood supply, venous drainage and Innervation of the penis?

Answer 8

Blood supply: internal pudendal arteries, external pudendal arteries, deep arteries, arteries of the bulb (mainly dorsal arteries).
Venous drainage: deep and superficial dorsal veins
Innervation: dorsal nerve of the penis ( branch of pudendal)

Question 9

Venous drainage of the penis?

Answer 9

deep and superficial dorsal veins.

Question 10

Why is he dorsal vein of the penis names this when it sits on the ventral aspect?

Answer 10

Because when the penis is erect, the vein sits on the dorsal surface

Question 11

What are the layers of the scrotum?

Answer 11

• Skin
• Dartos fascia and dartos muscle
• External spermatic fascia
• Cremaster muscle
• Cremasteric fascia
• Internal spermatic fascia
• Tunica vaginalis (parietal)
• Tunica vaginalis (visceral)
• Tunica albuginea (innermost layer covering testis)

Question 12

The testis are suspended in the scrotum by what structure?

Answer 12

Spermatic cord

Question 13

What is tunica vaginalis?

Answer 13

visceral & parietal layers of peritoneum around testes

Question 14

What is tunica albuginea?

Answer 14

“white coat” tough fibrous outer surface of testis.

Question 15

Tunica albuginea forms what inside testis?

Answer 15

Septa

Question 16

What is the route of mature spermatozoa?

Answer 16

Mature spermatozoa move from seminiferous tubules through rete testis and efferent ductules to be stored in the epididymis awaiting ejaculation

Question 17

Blood supply of testes?

Answer 17

• Testicular arteries

* Artery of ductus deferens

Question 18

Venous drainage of testes?

Answer 18

• Pampiniform plexus to right testicular vein to IVC

* Pampiniform plexus to left testicular vein to Left renal vein.

Question 19

Spermatic cord contains what structures?

Answer 19

• Ductus deferens
• Testicular artery
• Artery of ductus deferens
• Cremasteric artery
• Pampiniform plexus
• Sympathetic nerve fibres
• Genitofemoral nerve
• Lymphatic vessels

Question 20

The spermatic cord has three coverings, what are these?

Answer 20

• Internal spermatic fascia
• Cremasteric fascia
• External spermatic fascia

Question 21

The cremasteric fascia is derived from what?

Answer 21

Derived from fascia of internal obliques and contains loops of cremaster muscle

Question 22

The internal spermatic fascia is derived from what?

Answer 22

derived from transversalis fascia

Question 23

The external spermatic fascia is derived from what?

Answer 23

derived from external oblique aponeurosis and fascia

Question 24

Cremaster muscle innervated by?

Answer 24

genitofemoral nerves (L1-L2)

Question 25

Spermatic Cord begins where?

Answer 25

deep inguinal ring lateral to inferior epigastric vessels.

Question 26

The spermatic cord exits at?

Answer 26

superficial inguinal ring.

Question 27

The spermatic cord ends where?

Answer 27

in scrotum at posterior pole of testis

Question 28

The vas deferens crosses over what structure to enter the pelvis?

Answer 28

External iliac vessels

Question 29

Seminal VESICLE is located where in relation to the bladder, rectum and prostate?

Answer 29

Posterior to bladder Anterior to rectum Superior to prostate

Question 30

What do the seminal VESICLE secrete?

Answer 30

thick alkaline fluid with fructose and coagulating agent that mixes with sperm as they enter the ejaculatory duct and urethra

Question 31

Ejaculatory Ducts formed by union of what two structures?

Answer 31

ducts of seminal vesicles with ductus deferens

Question 32

Prostatic secretions join seminal fluid in prostatic | urethra AFTER what?

Answer 32

ejaculatory ducts have terminated

Question 33

Prostatic secretion secretes what structure?

Answer 33

1/3 of semen volume; milky, slightly acidic contains citrate and enzymes that activates sperm.

Question 34

Prostatic secretion goes where?

Answer 34

Enters prostatic urethra via ducts when prostatic smooth muscle contracts during ejaculation.

Question 35

Name a condition of the prostate?

Answer 35

Benign hypertrophy of the prostate (BHP) is common after middle age. Enlarged prostate projects into urinary bladder and distorts prostatic urethra impeding urination

Question 36

What happens to urination due to an inflamed prostate?

Answer 36

Enlarged prostate projects into urinary bladder and distorts prostatic urethra impeding urination

Question 37

What is a TURP and what does it involve?

Answer 37

Transurethral resection of prostate. Involved sectioning and removing parts of the prostate through the penis with no external incision

Question 38

Bulbourethral Gland Innervation?

Answer 38

Under parasympathetic stimulation: Secrete clear mucous-like fluid during sexual arousal which neutralises traces of acidic urine in the urethra and lubricates glans penis.

Question 39

Name the four parts of the male urethra?

Answer 39

1. Intramural 2. Prostatic part [3-4 cm] 3. Intermediate 4. Spongy urethra [15cm]

Question 40

Innervation of internal genital organs of the male? Sympathetic and parasympathetic

Answer 40

• Pre-synaptic sympathetic fibres originating from T12-L3 to sympathetic trunk to lumbar splanchnic nerves/hypogastric and pelvic plexuses. • Pre-synaptic parasympathetic fibres originate from S2-S3 to pelvic splanchnic nerves to inferior hypogastric/pelvic plexuses. Synapses with post-synaptic sympathetic/parasympathetic neurons occur within plexuses.

Question 41

Ductus deferens, seminal vesicles, ejaculatory ducts and prostate richly innervated by what type of fibres?

Answer 41

Sympathetic fibres

Question 42

What is the processes of erection?

Answer 42

``` • Parasympathetic stimulation ↓ • Nitric oxide release ↓ • Relaxation (dilation) of vascular smooth muscle ↓ • Engorgement of erectile bodies with blood (compresses drainage veins -> retards blood outflow) ```

Question 43

What is the processes of ejaculation?

Answer 43

• Ducts and glands contract to empty secretions--->internal urethral sphincter closes(sympathetic via lumbar splanchnic nerves) ----> bulbospongiosus muscles contracts from pudendal nerves---->peristaltic-like contractions of ductus deferens via sympathetic stimulation

Question 44

What is the Innervation of the testes?

Answer 44

Posterior scrotal nerve