Abdominal muscles

Question 1

External Oblique

Answer 1

O: External surfaces of 5-12 ribs

I: Linea alba, pubic tubercle, and anterior half of iliac crest

N: Thoraco-abdominal nerves (T7-T11) and Subcostal nerve (T12)

A: compresses/supports viscera & flexes/rotates trunk
- unilateral = contralateral rotation
-bilateral = trunk flexion

Question 2

Internal Oblique

Answer 2

O: THORACOLUMBAR FASCIA, anterior 2/3rd of iliac crest & connective tissue deep to lateral 3rd of inguinal ligament

I: Inferior boarders of 10-12 ribs, linea alba, &pecten pubis via conjoint tendon

N:Thoraco-abdominal nerves (T6-T12 anterior rami of spinal nerves) & L1 nerve

A: Compress/supports viscera & flexes/rotates trunk
- Unilateral = ipsilateral trunk rotation
-Bilateral = trunk flexion

Question 3

Transversus abdominis

Answer 3

O: Internal surfaces of 7-12 costal cartilages, THORACOLUMBAR FASCIA, iliac crest & connective tissue deep to lateral 3rd inguinal ligament

I: Linea alba w/ aponeurosis of internal oblique, pubic crest & pecten pubis via conjoint tendon

N: Thoraco-abdominal nerves (T6-T12 anterior rami of spinal nerves) & L1 nerve

A: Compresses/supports viscera
- Lumbar stabilizer

Question 4

Which muscles form the Rectus sheath & Linea Alba due to their aponeuroses?

Answer 4

External Oblique
Internal Oblique
Transversus abdominis

Question 5

Rectus Abdominis

Answer 5

O: Pubic symphysis & pubic crest

I: Xiphoid process & 5-7 costal cartilages

N: Thoracoabdominal nerves (T6-T12 spinal nerves)

A: Flexes trunk & compresses abdominal viscera, stabilizes/controls tilt of pelvis (anti-lordosis)