Male Ext Genitalia; Clinical Correlation to Urethral Injury

Question 1

Sscrotum fascia- what are their extensions and attachments?

Answer 1

• Ext oblique extends to form the ext spermatic fascia
  
  • ​ Attaches to the borders of the external inguinal ring.
• Int oblique extends to form the cremaster muscle & fascia
  
  • ​Attaches to the
    
    • inguinal ligament & iliopsoas laterally
    • pubic tubercle medially.
• Transversalis fascia becomes the int spermatic fascia in the scrotum

Question 2

Layers of testis

Answer 2

Some Dirty Englishmen Called It Testis

• Skin
• Dartos fascia (has smooth muscle) - continues with Colle’s and Scarpa’s
• Ext spermatic fascia
• Cremasteric fascia
• Internal spermatic fascia
• Testis

Question 3

Anatomy of epididymus

Answer 3

• Head, body, and tail
• Tail is continuous with ductus deferens

Question 4

Course & contents of spermatic cord

Answer 4

Spermatic cord travels through the inguinal canal into the scrotum

• Testicular artery
• Cremaster
• Genitofemoral nerve femoral branch
• Pampiniform plexus of veins
• Testis

Question 5

Scrotal lymphatics

Answer 5

• Does not cross the median raphe
• Drains into the superficial inguinal nodes on the ipsilateral side
  *

Question 6

The smooth muscle of the dartos fascia is continuous with what other fascia?

Answer 6

Colles fascia

Scarpa’s fascia

Darto’s fascia of penis

Question 7

As scarpa’s fascia goes downward, it becomes what ?

Answer 7

Darto’s fascia- the outermost fascia.

Question 8

The deep/buck’s fascia surrounding the penis envelops the

Answer 8

wraps around the corpus cavernosa and corpus spongiosum individually

Question 9

Anterior distal urethral lesion results in extravasation where and between what fascia?

Answer 9

Into scrotum and abdomen under Scarpa’s/Dartos

Question 10

The fascia of scrotum connect via the tunica vaginalis (extension of parietal peritoneum) that surrounds the testis

Answer 10

Parietal peritoneal surface of the tunica can produce fluid, but if it’s not absorbed –> hydrocele

Question 11

Course of the vas deferens

Answer 11

Goes from tail of epididymus, up the spermatic cord, through the superficial & deep inguinal rings, posterior to the inferior epigastric artery, anterior to the ureter, and joins with the duct of the seminal vesicles to drain into the ejaculatory ducts.

Cut in vasectomy

Question 12

Anatomy of testis

Answer 12

• Comes down from spermatic cord
• Has epididymis on anterior surface
• Has small body at its upper pole called the appendix testis

Question 13

Vascular supply of the testicle

Answer 13

• Testicular (internal spermatic) artery - biggest
  
  • From abdominal aorta
  • Transverses in retroperitoneum, then through inguinal ring
• Artery of vas deferens/Deferential artery
  
  • ​From internal iliac artery OR superior vesical artery
• Cremasteric (external spermatic) artery
  
  • From inferior epigastric artery
  • Primarily supplies tunica vaginalis

Question 14

Testicular venous drainage (not an LO)

Answer 14

Pampiniform plexus: group of veins anastomose with each other and the deferential veins.

Left testis drains into the left renal vein

Right testis drains into anterior surface of the IVC

Question 15

Where do lymphatics from the testis drain? Difference in the course between right and left?

Answer 15

Left testis lymphatics drain into the para-aortic and interaortocaval lymph nodes to drain in the thoracic duct.

Right testis lymphatics runs along the vena cava and then move to the left side of your body to reach those nodes.

Thus, the left doesn’t cross over, but the right will cross to the left due to generalized lymphatic flow and thoracic duct

Question 16

Testicular tumor - what approach do you use and why?

Answer 16

You take the inguinal approach instead of the scrotal appraoch to avoid spreading the tumor via the differences in lymphatic drainage.

Question 17

Testicular cancer (micrometastatic or residual disease) follow what lymph node chain?

Answer 17

Ipsilateral lymph node chain

Question 18

Ultrasounds for scrotal contents - uses

Answer 18

• Can use high frq because testicles are so close to skin
• Determine if theres a hydrocele or testicular torsion

Question 19

3 layers of scrotum seen on ultrasound

Answer 19

• Outer hyper-reflective layer (skin)
• Hypo-reflective intermediate
• Hyper-reflective inner layer (tunica albuginea)

The testicle itself is a smooth, homogenous structure

Question 20

Mediastinum testis - what does it do and what does it look like on an ultrasound?

Answer 20

Mediastinum testis drains the seminiferous tubules into the rete testes

On an ultrasound, it’s a highly reflective linear structure at the posterior superior aspect of the testicle

Question 21

Cremasteric Reflex

Answer 21

1. Stroking the inner thigh stimulates the ilioinguinal nerve (L1)
2. Activates motor neurons in the genital branch of the genitofemoral nerve
3. Ipsilateral cremasteric contraction & Testicular elevation

Question 22

Structure of penis

Answer 22

• Corpus cavernosa: paired erectile bodies that prolongate proximally as the crus and attaches to the pubic arch
  
  • ​Separated by a septum proximally, but is permeable distally to allow free communication between their vascular spaces
• Urethra travels through the corpus spongiosum, with its proximal segment known as the bulb
  
  • Reaches into the glans penis: expansion of corpus spongiosum

Question 23

Cross-section of the penis

Answer 23

• In the dartos, you see the superficial dorsal veins
• Buck’s fascia goes around the corpora cavernosa and the corpus spongiosum
• Urethra is inside the corpus spongiosum
• Cavernosal artery runs through the middle of the corpora cavernosa to supply the erectile tissue
• Tunica albuginea (holds rigidity of erections) has an outer longitudinal layer and an inner circular layer.

Question 24

Tunica albuginea

Answer 24

​Tunica albiginea: tough, collagenous connective tissue layer that envelops the corpora cavernosa; holds rigidity of erections

• Circular inner layer bundles support and contain the cavernous tissue
• Intracavernous pillars radiating from the inner layer act as struts to support the erectile tissue during erection
  
  • The corpus spongiosum lacks this to ensure a low-pressure structure during erection
• Longitudinal outer-layer bundles extend from the glans to the proximal crura
  
  • Insert into the inferior pubic rami, but absent at the 5’ and 7’ o clock positions

Question 25

The superficial artery of penis arises from \_\_\_\_. The deep artery of the penis arises from \_\_\_\_. Branches of the common penile artery.

Answer 25

Superficial artery from the **external pudendal artery.** Deep artery from the **internal pudendal**, which becomes the **common penile artery** after giving off a branch to the perineum * Dorsal * Bulbourethral * Cavernous Joins to form a vascular ring near the glans

Question 26

Penile venous drainage

Answer 26

Tiny venules *inside* the corpora tissues travel within the trabeculae between the tunica and peripheral sinusoids to form the **subtunical venous plexus** and exiting as **emissary veins.**

Question 27

Lymphatics from the _skin_ of the penis drain where?

Answer 27

Superficial inguinal lymph nodes Subinguinal lymph nodes

Question 28

Lymphatics from the _shaft_ o the penis drain where?

Answer 28

They coverge on teh dorsal side and ramify to both sides of the groin to drain into **inguinal lymph nodes**

Question 29

Lymphatic drainage & Penile Cancer

Answer 29

Penile cancer will spread to the superficial inguinal lymph nodes --\> must dissect it and remove the lymphatic tissue there.

Question 30

Sensory innervation of penis

Answer 30

**Dorsal nerves,** especially at the glans

Question 31

Where is the penis' somatic nerve supply originate from?

Answer 31

Somatic nerve supply from **S2,S3, and S4** travels along the **pudendal nerve** on the dorsal side.

Question 32

Autonomic stimulation of erection/detumescence

Answer 32

**Erection** requires _sacral parasympathetic_ stimulation of * Pelvic splanchnics (S2-S4) * Cavernous nerves **Detumescence** requires _thoracolumbar sympathetic_ stimulation of the sympathetic trunk

Question 33

What muscles are involved in erections?

Answer 33

**Corpus cavernosum** **smooth muscle** is contracted at all times **Bulbospongiosus muscle** covers the corpus spongium; it propels the ejaculate **Ischiocavernosus muscles/erector penis** acts as a pump to increase penile turgor beyond arterial pressure

Question 34

Erection & Ejaculation

Answer 34

1. *Parasympathetic* fibers of pelvic splanchnics (S2-S4) & cavernous nerves 1. relax cavernous vessels 2. engorges erectile tissue with blood 3. cause bulbourethral & urethral glands to secrete mucous 2. *_​_Sympathetic* fibers 1. Contracts seminal vesicles & prostate to move sperm to **prostatic urethra --\>** combine with bulbourethral secretions + penile urethral gland secretions 3. **Pudendal nerves & thoracic sympathetic stimulation** causes internal urethral sphincter & bulbospongiosus to contract & ejaculate 1. Help from parasympathetic stimulation of **urethral smooth muscle**

Question 35

Which artery is responsible for engorgement of the glans durign erection?

Answer 35

Dorsal artery

Question 36

Which artery supplies teh bulb and corpus spongiosum?

Answer 36

Bulbourethral artery

Question 37

Fundiform ligament

Answer 37

**Fundiform ligament**: thickening of superficial fascia that is superficial to the suspensory ligament; it descends from the linea alba, splits to surround the penis, and then unites and blends inferiorly with the dartos fascia, forming the **scrotal septum** "sling" around the base of the penis for support

Question 38

Suspensory ligament

Answer 38

Arises from Buck's fascia Initiates at the pubic symphysis and terminated at the tunica albuginea of the corpora cavernosa Anchors the penis

Question 39

Anterior vs posterior male urethra

Answer 39

**Anterior urethra:** distal from external urethral sphincter * Membranous urethra * Spongy urethra **Posterior urethra**: proximal to external urethral sphincter * Internal urethral sphincter * External urethral sphincter * Prostatic urethra * Pre-prostatic urethra

Question 40

In placing a catheter in men, where will you feel slight resistance?

Answer 40

Membranous urethra. Due to increase in striated sphicnteric resistance (patient is uncomfortable) or prostatic enlargement.

Question 41

Two sphincters for urinary continence

Answer 41

**External urinary sphincter**: under voluntary control of skeletal muscle **Internal urinary sphincter**: under involuntary control of smooth muscle; Contracts during ejaculation due to sympathetics

Question 42

4 parts of the urethra

Answer 42

* **Preprostatic part**: before the prostate * **Prostatic part:** before ext urethral sphincter * **Membranous part** * **Spongy part**

Question 43

Rupture of the urethra with Buck's fascia intact

Answer 43

Urinary leakage confined to penis

Question 44

Penile urethra with Buck's fascia ruptured -\> where is urine extravasation?

Answer 44

Scrotum; penis; superficial pouch; perneum; deep to Colles' fascia; deep to Darto's fascia; lower abdominal wall; deep to Scarpa's fascia Fluid collects between Buck's fascia and dartos layer. No pelvic drainage

Question 45

A male driver has sustianed severe trauma to the pelvic region in a car crash, resulting in a tearing of the prostato membranous urethral junction (just superior to the ext urethral sphincter). Blood and urine from this injury will collect where? * Anterior lower abdominal wall deep to Scarpa's fascia * Beneath the deep (Buck's) fascia of the penis * Beneath the superficial perineal (Colles') fascia * Deep to the dartos fascia of the scrotum and penis * Subperitoneal (retroperitoneal) space

Answer 45

It's proximal to the urethral sphincter, so subperitoneal/retroperitoneal space.

Question 46

Dissemination of cancer cells form the left testis would enter the testicular veins and then first enter which of the following veins?

Answer 46

Left renal. ## Footnote Left drainage -\> spermatic cord -\> left renal vein.

Question 47

Rupture of the male urethra can lead to extravasation of urine. If the injury perforates the penile urethra and Buck's fascia, into which of the followign spaces might the colleciton of urine be found? * Beneath the dartos and the Buck's fascia * Between the Camper's superficial fascia and the Scarpa's fascia of lower abdominal wall * Deep to Scarpa's fascia of lower abdominal wall * Exteranl to dartos fascia of the scrotum * In the retroperitoneum of the lower pelvis

Answer 47

Deep to the Scarpa's fascia of lower abdominal wall. Around the penis itself, the fluid would be between the dartos fascia and the Buck's fascia, not beneath both fascial layers

Question 48

Rupture of urethra at the prostatomembranous junction

Answer 48

Leakage into the retroperitoneum

Question 49

Rupture of what part of the urethra will cause accumulation of fluid in the superficial perineal pouch?

Answer 49

**Spongy urethra** only; can also go up to abdominal wall because Colles' fascia is continuous with Scarpa's fascia ## Footnote Note: "bulbar urethra" is a part of spongy urethra

Question 50

Cavernous nerves provide efferent fibers to what?

Answer 50

Erectile bodies of the penis. Cavernous nerves are post-ganglionic parasympathetic fibers; the preganglionic fibers derive from the pelvic splanchnic nerve (S2-S4)

Question 51

What nerve feeds the glands penis?

Answer 51

Pudendal nerve

Question 52

What plexus innervates the seminal vesicles?

Answer 52

Inferior hypogastric plexus