Anterior abdominal wall and inguinal region

Question 1

Name the three layers of muscle that comprise the anterolateral abdominal wall from superficial to deep.

Answer 1

External oblique, internal oblique, transversus abdominus.

Question 2

What is the name of the vertical-running muscle that lies in the midline?

Answer 2

Rectus abdominus.

Question 3

In what direction do the fibres of external oblique run?

Answer 3

P \\ A ie ‘front pocket’ muscles.

Question 4

In what direction do the fibres of internal oblique run?

Answer 4

P //// A ie ‘back pocket’ muscles.

Question 5

In what direction do the fibres of transverse abdominus run?

Answer 5

P \\ A except more horizontal near the umbilicus.

Question 6

What is an aponeurosis?

Answer 6

A thin, sheet-like tendon, analogous to a cord-like tendon.

Question 7

What are the functions of the anterior abdominal wall muscles?

Answer 7

Flexing the trunk forwards, flexing the trunk from side to side, compressing the abdominal contents, supporting and containing abdominal contents.

Question 8

What is the nerve supply to the skin and muscle of the anterior abdominal wall?

Answer 8

Anterior cutaneous branches of T7-12 from segmented spinal nerves.

Question 9

What is the name of the anterior abdominal fascia?

Answer 9

Scarpa’s fascia

Question 10

What is the name of the name of the fascia of the perineum continuous with Scarpa’s fascia?

Answer 10

Colle’s fascia

Question 11

How is the the inguinal ligament formed?

Answer 11

The lower border of the external oblique aponeurosis forms the inguinal ligament on each side. This thickened reinforced free edge of the external oblique aponeurosis passes between the anterior superior iliac spine laterally and the pubic tubercle medially. It folds under itself forming a trough, which plays an important role in the formation of the inguinal canal.

Question 12

How do the fibres of transversus abdominus relate to the inguinal ligament?

Answer 12

The roof of the inguinal canal is formed by the arching fibres of the transversus abdominus and the internal oblique muscle. They pass from their lateral points of origin from the inguinal ligament to their common medial attachment as the conjoint tendon.

Question 13

What and where is the conjoint tendon?

Answer 13

The combined insertion of transversus abdominus and internal oblique muscles into the pubic crest.

Question 14

What are the attachments of rectus abdominus?

Answer 14

Pubic symphysis and costal margin.

Question 15

Describe the arrangement of the rectus sheath above the umbilicus.

Answer 15

External oblique aponeurosis is superficial to rectus abdominus. Internal oblique aponeurosis splits - one layer is superficial to rectus abdominus, one layer deep. Transversus abdominus aponeurosis lies deep to rectus abdominus.

Question 16

Describe the arrangement of the rectus sheath below the umbilicus.

Answer 16

All aponeuroses lie superficial to rectus abdominus.

Question 17

Define the arcuate line.

Answer 17

Horizontal line that demarcates lower limit of the rectus sheath. Point at which the aponeuroses change their configuration over the rectus sheath.

Question 18

Name the three coverings of the spermatic cord from superficial to deep.

Answer 18

External spermatic fascia, cremasteric fascia, internal spermatic fascia.

Question 19

Name the covering of the testicle. What is its embryological origin?

Answer 19

Tunica vaginalis. Originates from processus vaginalis.

Question 20

What is the cremasteric reflex?

Answer 20

Contraction of the cremaster muscle and elevation of the testes. Reflex arc occurs when you touch the skin at and around the anterior aspect of superior thigh. Sensory fibres enter spinal cord at L1, where they stimulate motor fibres carried in genital branch of genitofemoral nerve.

Question 21

What does the spermatic cord contain?

Answer 21

Ductus deferens, artery of ductus deferens, testicular artery, cremestaric artery, pampiniform venous plexus, sympathetic nerve fibres, genital branch of genitofemoral nerve, lymphatic vessels

Question 22

What lies at the medial and lateral borders of the deep inguinal ring

Answer 22

Medial border: inderior epigastric artery Lateral: inguinal ligament

Question 23

Where does the deep inguinal ring lie?

Answer 23

Midway between the ASIS and the pubic tubercule.

Question 24

What are the boundaries of the superficial inguinal ring?

Answer 24

Superior: Aponeurosis of external oblique Inferior: Pubic tubercule Lateral: Inguinal ligament Medial: Conjoint tendon

Question 25

What is the approximate length of the inguinal canal?

Answer 25

4cm

Question 26

What forms the roof of the inguinal canal?

Answer 26

Arching fibers of the transversus abdominus and internal oblique muscles

Question 27

What forms the floor of the inguinal canal?

Answer 27

The medial one-half of the inguinal ligament.

Question 28

What forms the posterior wall of the inguinal canal?

Answer 28

Transversalis fascia reinforced by the conjoint tendon.

Question 29

What forms the anterior wall of the inguinal canal?

Answer 29

Aponeurosis of external oblique.

Question 30

How does the ilioinguinal nerve enter the inguinal canal and what does it supply?

Answer 30

Pierces the internal oblique then accompanies the spermatic cord through the superficial ring.

Question 31

Describe in indirect inguinal hernia.

Answer 31

The abdominal contents protrude through the deep inguinal ring, lateral to the inferior epigastric vessels and can enter the scrotum. Can be caused by a failure of the processus vaginalis to close.

Question 32

Describe a direct inguinal hernia.

Answer 32

Occur medial to the inferior epigastric vessels. When bowel protrudes through a weak spot in the transversalis fascia and can exit through the superficial inguinal ring. They are incapable of protruding into the scrotum.