W3: Inguinal region and hernias

Question 1

Mid-inguinal point

Answer 1

halfway between the pubic symphysis and the anterior superior iliac spine. The femoral pulse can be palpated here.

Question 2

Midpoint of the inguinal ligament

Answer 2

halfway between the pubic tubercle and the anterior superior iliac spine (the two attachments of the inguinal ligament). The opening to the inguinal canal is located just above this point.

Question 3

Walls of inguinal canal

Answer 3

Anterior wall – formed by the transversalis fascia, reinforced medially by the internal oblique and transver-

sus abdominis aponeuroses (called the conjoint tendon)

Posterior wall – transversalis fascia.

Roof – formed by the transversalis fascia laterally, internal oblique and transversus abdominis aponeuroses centrally and the external oblique aponeurosis medially.

Floor – inguinal ligament (a ‘rolled up’ portion of the external oblique aponeurosis), thickened medially by the lacunar ligament.

Question 4

deep (internal) ring

Answer 4

is found above the midpoint of the inguinal ligament. which is lateral to the epigastric vessels. The ring is created by the transversalis fascia, which invaginates to form a covering of the contents of the inguinal canal.

Question 5

Superficial ring

Answer 5

The superficial (external) ring marks the end of the inguinal canal, and lies just superior to the pubic tubercle. It is a triangle shaped opening, formed by the evagination of the external oblique, which forms another covering of the inguinal canal contents. This opening contains intercrural fibres, which run perpendicular to the aponeurosis of the external oblique and prevent the ring from widening.

Question 6

What does the canal contain in males?

Answer 6

spermatic cord and the ilioinguinal nerve

Question 7

What does the canal contain in females?

Answer 7

round ligament of the uterus and the ilioinguinal nerve

Question 8

What is the ilioinguinal nerve?

Answer 8

sensory innervation to the skin of the upper anteromedial thigh and partially the external genitalia. Moreover, it provides motor innervation to the internal abdominal oblique and transversus abdominis muscles.

Question 9

Where is the deep inguinal ring?

Answer 9

1.5cm superior to the midpoint of the inguinal ligament

Question 10

What is the mid-inguinal point a marker of? Not the midpoint of the inguinal ligament!

Answer 10

Landmark of the femonral artery

Question 11

Direct inguinal hernia

Answer 11

A direct inguinal hernia is a protrusion of small bowel through a weakness within the transversalis fascia, typically within the inguinal triangle.

The inguinal triangle is formed superolaterally by the inferior epigastric vessels, medially by the lateral margin of the rectus sheath, and inferiorly by the inguinal ligament (see diagram below).

As such, direct inguinal hernias are seen medial to the inferior epigastric vessels. These hernias can then either pass around or though the inguinal canal.

Question 12

Indirect inguinal hernia

Answer 12

An indirect inguinal is a congenital protrusion of small bowel through a patent processus vaginalis and deep inguinal ring. As such, the herniation occurs lateral to the inferior epigastric vessels. These hernias typically leave the inguinal canal through the superficial inguinal ring to enter the scrotum/labia majora.

Question 13

Where do the epigastric arteries run?

What do they supply?

Answer 13

External iliac

Anterior abdominal wall

Question 14

Femoral hernias

Answer 14

In women, femoral hernias are far more common. Femoral hernias are protrusions of small bowel into the femoral canal, the medial-most compartment of the femoral sheath.

The femoral sheath, bounded superiorly by the inguinal ligament, is a funnel-shaped continuation of the transversalis fascia of the ab- domen, that surrounds the femoral vein, artery, nerve and lymphatics of the superior part of the lower limb.

Usually, the femoral canal’s superior aperture (femoral ring) is closed. Weakness of the femoral ring can allow small intestine to pass into the canal, resulting in the formation of a hernia.

Femoral hernias can be distinguished from inguinal hernias by their location: they are found inferior to the inguinal ligament, although this is often difficult to determine in clinical practice.

Question 15

Which type of hernia is more likely to be irreducible?

Answer 15

E.g. not able to be reduced back into the abdomen

Femoral

1.a ;2.a ;3.e ;4.d ;5.b ;6.c ;7.a ;8.b ;9.a ;10.d ;11.b ;12.b ;13.c

Question 16

2. After surgery to remove a cancerous prostate gland, the patient no longer can obtain an erection. It is likely that the surgery damaged which of the following nerves?

Answer 16

Pelvic splanchnic

Question 17

4. A 72-year-old man develops a hydrocoele which is being surgically managed. As part of the procedure the surgeons divide the tunica vaginalis. From which of the following is this structure derived?

Answer 17

Peritoneum

Question 18

11. The central zone of the prostate surrounds which part of the genitourinary tract?

Answer 18

Ejaculatory ducts

Question 19

The cremasteric reflex, which triggers the testes to as- cend within the scrotum, is brought about by stimulation of which nerve roots?

Answer 19

L1-L2