1.3 Inguinal Canal

Question 1

When is the inguinal canal formed?

Answer 1

During the relocation of the gonads during foetal development

Question 2

What is the inguinal canal formed from?

Answer 2

Layers of anterior abdominal wall as these layers push through the wall obliquely, thus forming a canal

Question 3

How long is the inguinal canal?

Answer 3

Approx 4cm

Question 4

Where does the inguinal canal lie in relation to the medial half of the inguinal ligament?

Answer 4

Parallel to and above

Question 5

Which 2 bony points of the hip bone is the inguinal ligament attached to?

Answer 5

Superolaterally = anterior superior iliac crest
Inferomedially = pubic tubercle

Question 6

What are the boundaries of the inguinal ligament?

Answer 6

Anterior wall
Posterior wall
Roof
Floor

Question 7

What forms the anterior wall of the inguinal canal?

Answer 7

‘2 Aponeuroses’

Aponeurosis of external oblique reinforced laterally by aponeurosis of internal oblique

Question 8

What forms the posterior wall of the inguinal canal?

Answer 8

‘2 Ts’
Transversalis fascia
Conjoint Tendon

Question 9

What forms the roof of the inguinal canal?

Answer 9

'2 Muscles'
Internal oblique 
Transversus abdominis
(laterally by transversalis fascia)
(medially by medial crus and intercrural fibres)

Question 10

What forms the floor of the inguinal canal?

Answer 10

‘2 Ligaments’
Inguinal ligament
(thickened by) Lacunar ligament

Question 11

What is found in the medial 1/3rd of the anterior wall of the inguinal canal?

Answer 11

The superficial inguinal ring

Question 12

What is found in the lateral 1/3rd of the anterior wall of the inguinal canal?

Answer 12

The muscular part of the internal oblique

Question 13

What is found in the medial 1/3rd of the posterior wall of the inguinal canal?

Answer 13

The conjoint tendon

Question 14

What is found in the lateral 1/3rd of the posterior wall of the inguinal canal?

Answer 14

The deep inguinal ring

Question 15

What is the inguinal ligament?

Answer 15

A ‘rolled up’ portion of the external oblique aponeurosis

Question 16

Where is the deep inguinal ring situated?

Answer 16

An opening found superiorly

Question 17

Where is the superficial inguinal ring situated?

Answer 17

An opening found inferiorly

Question 18

What is the relationship of the deep inguinal ring to the inferior epigastric vessels?

Answer 18

It is lateral to the inferior epigastric artery/vein

Question 19

Where does the superficial ring lie in relation to the pubic tubercle?

Answer 19

Ring is bound superolaterally by tubercle

Question 20

What are the epigastric vessels branches of superiorly?

Answer 20

Internal thoracic artery

Question 21

What are the epigastric vessels branches of inferiorly?

Answer 21

External iliac artery

Question 22

List the contents of the male inguinal canal?

Answer 22

• spermatic cord
• blood & lymphatic vessels
• ilioinguinal nerve

Question 23

List the contents of the female inguinal canal?

Answer 23

• round ligament of uterus
• blood & lymphatic vessels
• ilioinguinal nerve

Question 24

What are the 3 types of hernia?

Answer 24

1. inguinal
2. femoral
3. umbilical

Question 25

What is the most common type of hernia?

Answer 25

Inguinal

Question 26

How can inguinal hernias be classified?

Answer 26

Direct and indirect (indirect is more common - 2/3rds of inguinal hernias)

Question 27

What does an indirect hernia result from?

Answer 27

A congenital weakness in the deep inguinal ring, allowing abdominal contents to enter into the inguinal canal lateral to the inferior epigastric vessels, and even out of the deep inguinal ring

Question 28

What happens in a direct hernia?

Answer 28

Abdominal contents do not pass through the deep inguinal ring, but push through a weak spot in the muscles making up the posterior wall of the inguinal canal, allowing contents to enter the canal and, again, even pass through the superficial inguinal ring

Question 29

Where do femoral hernias occur?

Answer 29

Below the inguinal ligament

Question 30

What happens in a femoral hernia?

Answer 30

When Abdominal Contents pass into the weak area at the Posterior Wall of the Femoral Canal (medial to the Inferior Epigastric Vessels) (more common in females & risk of strangulation is high)

Question 31

What happens in an umbilical hernia?

Answer 31

Abdominal Contents pass through a weakness at the site of the passage of the Umbilical Cord through the Abdominal Wall. In adults these are acquired rather than congenital, although abnormal Linea Alba fibers can contribute to this