4.2 Muscles of the Anterior Abdominal Wall

Question 1

Identify the inguinal ligament.

Answer 1

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Question 2

Identify the Camper’s fascia and recall the alternative name for this layer.

Answer 2

Superficial Fatty Layer

Question 3

Identify the Scarpa’s fascia and recall the alternative name for this layer.

Answer 3

Deep Membranous layer

Question 4

Identify the external oblique muscle, it’s attachments, function, and innervation.

Answer 4

-Originates from the outer surfaces of ribs 5 to 12.
-It inserts via the aponeurosis onto the linea alba and the pubic tubercle. It also inserts on the anterior iliac crest
-Function:
unilaterally to bend the trunk to the same side and to rotate the trunk to the opposite side.
bilaterally to flex the trunk, to compress the abdomen, and to stabilize the pelvis.
-Innervation: Intercostal nerves (T7 to T12).

Question 5

Identify the aponeurosis of the external oblique.

Answer 5

-

Question 6

Identify the anterior layer of the rectus sheath.

Answer 6

-

Question 7

Identify the linea alba.

Answer 7

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Question 8

Identify the superficial inguinal ring.

Answer 8

-

Question 9

Identify the spermatic cord and round ligament.

Answer 9

-

Question 10

Identify the medial and lateral crus as well as the intercurural fibers.

Answer 10

Crus: the medial and lateral legs of the superficial inguinal ring.
Intercrural: arching over the superficial inguinal ring, connecting the two crura.

Question 11

Identify the ilioinguinal nerve. What muscle does this innervate and from where does it branch.

Answer 11

It exits the superficial inguinal ring. The ilioinguinal nerve branches from L1 and innervates the dartos muscle.

Question 12

Identify the internal oblique muscles, their attachment, function, and innervation.

Answer 12

Originates: from the deep layer of the thoracolumbar fascia, the intermediate line of the iliac crest, the anterior superior iliac spine, and the iliopsoas fascia
Inserts: It inserts onto the lower border of ribs 10 to 12 as well as onto the anterior and posterior layers of the linea alba
Function: (same as external obliques)
unilaterally to bend the trunk to the same side and to rotate the trunk to the opposite side.
bilaterally to flex the trunk, to compress the abdomen, and to stabilize the pelvis.
Innervation: Intercostal nerves (T7 to T12), iliohypogastric nerve, ilioinguinal nerve.

Question 13

Identify the transverses abdominis muscles, their attachment, function, and innervation.

Answer 13

-Originates from the inner surface of the 7th to 12th costal cartilages, the deep layer of the thoracolumbar fascia, the iliac crest, the inner lip of the anterior superior iliac spine, and the iliopsoas fascia
-Inserts: linea alba and the pubic crest
-Function:
unilaterally to rotate the trunk to the same side.
bilaterally to compress the abdomen.
Innervation:Intercostal nerves (T7 to T12), iliohypogastric nerve, ilioinguinal nerve.

Question 14

Identify the semilunar line.

Answer 14

lateral border of the rectus abdominis

Question 15

Identify the tendinous intersections of the rectus abdomens.

Answer 15

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Question 16

Identify the posterior layer of the rectus sheath.

Answer 16

-

Question 17

Identify the arcuate line and describe its importance.

Answer 17

• Located near the inferior posterior sheath of the rectus. It is a sometimes difficult to appreciate demarcation located roughly midway between the pubic symphysis and umbilicus. This line forms at the point where the posterior sheath of the rectus stops.
• Only the transversalis fascia and peritoneum line the posterior aspect of the rectus abdominis after the arcuate line. This deficiency allows the inferior epigastric artery and vein access into the rectus sheath where they often become embedded into the posterior aspect of the rectus abdominis.

Question 18

Identify the transversals fascia.

Answer 18

-

Question 19

Identify the deep inguinal ring.

Answer 19

a slit in the fascia transversalis,

Question 20

Identify the superior and inferior epigastric vessels.

Answer 20

Located on the deep surface of the rectus abdomens between the muscle and the posterior leaf of the rectus sheath.

Question 21

Identify the iliohypogastric nerve. What does this nerve innervate and from and what is it general course?

Answer 21

Originates from L1.

Travels across the lower abdomen. innervates muscle and skin over inguinal region.