Lecture 12: Inguinal Canal and Spermatic Cord

Question 1

Label

Answer 1

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Question 2

Label Key pelvic Landmarks

Answer 2

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Question 3

What are the 3 key pelvic Ligaments

Answer 3

Inguinal: ASIS → Pubic Tubercle, formed from the rolled edge of ext. oblique aponeurosis

Lacunar: connects inguinal and pectinate ligaments

Pectineal: pectineal line of pubic bone.

Question 4

What is the inguinal canal? How does it differ in males vs females?

Answer 4

• Oblique (to prevent herniation) passage thorugh lower part of abd. wall, ~4cm long
• From Deep Inguinal Ring to the Superficial Inguinal Ring

​Males: carries structures to/from testis and abdomen via the Spermatic cord (+ilioinguinal nerve)

Females: Carries round lig. of the uterus from the pelvis to the labia majora (+ilioinguinal nerve)

Question 5

Superficial Inguinal “Ring” (External oblique).

Answer 5

• Triangular shaped defect (nnot actually a ring) in Ext. Oblique aponeurosis
• Sup/lat to Pubic Tubercle
• Margins (crura) give rise to Ext. Spermatic Fascia of spermatic cord

Question 6

Deep Inguinal Ring (transversalis Fascia)

Answer 6

Oval opening of Transversalis Fascia

Landmarks:

• Mid-inguinal point (halfway between ASIS and Pubic symphysis)
• ~1.5-2cm above inguinal lig.
• Lateral to Inferior Epigastric Artery

TF gives rise to Internal Spermatic fascia (spermatic cord)

Round ligament fascia in women

Question 7

What are the 2 muscle layers between DIR and SFIR that contribute to the inguinal canal? Where do they meet?

Answer 7

Transversus Abdominis (doesn’t contribute to spermatic fascia) and Internal Oblique (gives rise to Cremaster muscle layer of spermatic cord)

Form common ‘Conjoint Tendon’ on the pubic crest/pectineal line

Question 8

What constitutes the borders of the Inguinal Canal, ant, post, floor and roof?

Answer 8

• Anterior:* Aponeurosis of Ext. Oblique and Int. Oblique (lat 1/3)
• Posterior:* Transversalis Fascia and Conjoint tendon (med. 1/3)
• Floor:* Inf. rolled edge of Ext. Oblique aponeurosis (inguinal lig) and Lacunar Ligament (medial)
• Roof:* Fibres of Int. Oblique and Transversus Abdominis

Question 9

What’s Hesselbach’s (inguinal) Triangle

Answer 9

• Site of Direct Hernia: pushes through weakened abdominal wall
• Corresponds to weak anterior wall (SFIR)

Borders: inguinal ligament, Inf. epigastric artery, lateral border of Rectus abdominis

Question 10

What is the Spermatic Cord and how does it arise?

Answer 10

It’s a collection of Structures which pass along the male inguinal canal to/from testis

Begins @ DIR, ends @ Testis

Arises from a peritoneal diverticulum called the ‘Processus Vaginalis’, pushes through the abdominal wall taking a tubular sheath from each layer

Question 11

What makes the 3x tubular sheath layers of the Spermatic Cord?

Answer 11

Transversalis Fascia (DIR) → Internal Spermatic Fascia

((Transversus abdominis contributes NOTHING))

• Internal Oblique* → Cremaster Muscle
• External Oblique* → External Spermatic Fascia

*Peritoneal out-pouching eventually pinches off leaving a remnant closed off sac “Tunica Vaginalis”

Question 12

What are the contents of the Spermatic Cord (within the 3x layers)?

Answer 12

3 Arteries:

• Testicular a. (from L2 abdo. aorta, supplies testis and epididymis)
• Artery of Vas Deferens (important for Vasectomy!)
• Cremasteric a.

3 Nerves:

• Genital branch of Genitofemoral n. (M(cremaster muscle) and S(skin of scrotum) @ L1-2)
• Sympathetic Nerves (from testicular plexus)
  
  • **ilioinguinal n (doesn’t actually travel in cord!)

3 Other Structures:

• Vas Deferens
• Lymphatics
• Tunica Vaginalis

1 Venous Plexus

• Pampiniform Plexus (for temp reg.)

Question 13

Draw in the spermatic cord contents!

Answer 13

..

Question 14

Lymphatics of the spermatic cord?

Answer 14

Drain to the Para-aortic nodes @L2 (origin of testicular artery)

Question 15

Why is the Ilioinguinal Nerve not actually part of the spermatic Cord?

Answer 15

Bc it DOESN’T travel in the cord NOR does it ‘travel through’ the inguinal canal.

• Pierces through the Int. Oblique (roof), runs outsde cord and exits the SIR.

Question 16

Testicular Torsion? Symptoms?

Answer 16

• When the Spermatic cord twists around, cutting off blood supply (→ ischaemia)
• Surgical emergency! Only a 6hr window to save testis

Symptoms:

• Acute and sever testicular/scrotal pain
• Pain referred to groin and lower abd.
• Absent/decreased cremasteric reflex
• Nausea/vomiting

Question 17

Normal Cremasteric Reflex?

Answer 17

1. Stroke Sup. Medial thigh
2. Stimulates sensory fibres of Femoral branch of GF nerve and ilioinguinal nerve (L1-2)
3. This stimulates motor fibres of Genital branch of GF n. ⇒ Cremaster muscle contracts on ipsilateral side, raising testis!

Question 18

Whats usually more reliable then Cremaster reflex method?

Answer 18

Ultrasound can see torsion via lack of testis blood flow

Question 19

Direct Inguinal Hernia

Answer 19

• Abdo. contents herniate through weak spot in fascof posterior wall of Inguinal canal (Hesselbachs triangle)
• MEDIAL to Inf. Epigastric a.
• *Males 10x** more likely
• *middle aged to Elderly** more likely

Question 20

Indirect Inguina Hernia

Answer 20

• Can be a congenital defect
• Occurs through DIR and through entirety of Inguinal canal → Scrotum within spermatic Cord
• LATERAL to inf. Epigastric a.
• Often seen in juveniles as DIR stil overlapped by SIR

Question 21

Femoral Hernia

Answer 21

• Herniation through femoral canal BELOW inguinal ligament
• Uncommon
• More likely in females (wider pelvis)