1.2 The Muscles of the Anterior Abdominal Wall

Question 1

What are the 3 Flat Muscles which form part of the Antero-Lateral Abdominal Wall?
(Superficial to Deep)

Answer 1

1. The External Oblique
2. The Internal Oblique
3. The Transverse Abdominis

Question 2

What are the Actions of the External Oblique?

Answer 2

1. Compress and Support the Viscera

2. Flex and Rotate the Trunk

Question 3

What are the Actions of the Internal Oblique?

Answer 3

1. Compress and Support the Viscera

2. Flex and Rotate the Trunk

Question 4

What are the Actions of the Transverse Abdominis?

Answer 4

Compress and Support the Viscera

Question 5

What is the innervation for the External Oblique?

Answer 5

The Anterior Rami of T7-T12:

1. The Thoraco-Abdominal Nerves of T7 to T11
2. The Sub-Costal Nerve - T12

Question 6

What is the innervation for the Internal Oblique?

Answer 6

The Anterior Rami of T7-L1

1. The Thoraco-Abdominal Nerves of T7 to T11
2. The Sub-Costal Nerve - T12
3. The First Lumbar Vertebrae - L1

Question 7

What is the innervation for the Transverse Abdominis?

Answer 7

The Anterior Rami of T7-L1

1. The Thoraco-Abdominal Nerves of T7 to T11
2. The Sub-Costal Nerve - T12
3. The First Lumbar Vertebrae - L1

Question 8

What are the Longitudinal Muscles which form part of the Antero-Lateral Abdominal Wall?

Answer 8

1. The Rectus Abdominis

2. Pyramidalis Muscle

Question 9

What are the Actions of the Rectus Abdominis?

Answer 9

1. Flexes the Trunk
2. Compresses Viscera
3. Controls the Tilt of the Pelvis

Question 10

Superior to the Umbilicus, where does the Rectus Abominis lie?

Answer 10

Within the Rectus Sheath

Question 11

Inferior to the Umbilicus, where does the Rectus Abdominis lie?

Answer 11

Deep to the Rectus Sheath

Question 12

What is the Pyramidalis Muscle?

Answer 12

A small triangular muscle, anterior to the Rectus Abdominis, contained within the Rectus Sheath which Tenses the Linea Alba (The White Fibrous Tissue between the Xiphoid Process and the Pubic Symphysis).

Question 13

What is the Rectus Sheath?

Answer 13

The Aponeurosis of the External Oblique, Internal Oblique, and Transverse Abdominis

Question 14

What is an Aponeurosis?

Answer 14

A sheet of White Fibrous Tissue which takes the place of a Tendon, in Sheet-Like Muscles (having wider areas of attachments)

Question 15

At what level is the position of the Umbilicus on the Abdominal Wall?

Answer 15

L3 / L4

Question 16

What is the Dermatome which covers the Umbilicus?

Answer 16

T10

Question 17

What is the Umbilicus a good Surface Landmark of?

Answer 17

The Abdominal Aorta Bifurcation

Question 18

Which Thoracic Spinal Segments innervate the Anterior Abdominal Wall?

Answer 18

T7 to T12