Lecture 15: Muscles of the Anterolateral wall

Question 1

What is significant about the muscle fascicles of the anterolateral abdominal wall?

Answer 1

they have crossing patterns for strength

Question 2

External Oblique

Answer 2

O: lower ribs
I: rectal sheath & hip
N: ventral rami
A: bilateral FL trunk (sup lumbar), unilateral ABD/ADD/ROT (inf lumbar & lower thoracic), Respiration (pulls rib cage down & compress abdomen to EXHALE when insertion is ribs)

Question 3

Internal Oblique

Answer 3

O: vertebral column via thoracolumbar fascia; hips
I: lower ribs; rectus sheath
N: ventral rami
A: bilateral FL trunk (sup lumbar), unilateral ABD/ADD/ROT (inf lumbar & thoracic), Respiration (pulls rib cage down & compress abdomen to EXHALE)

Question 4

Transversus abdominis

Answer 4

*important for lumbar stability
O: lower ribs; vertebral column via thoracolumbar fascia; hips
I: rectus sheath
N: ventral rami
A: Unilateral ABD/ADD/ROT (ROT at inf thoracic & inf lumbar), Respiration (compress ab to EXHALE)

Question 5

Rectus Abdominis

Answer 5

O: pubic symphysis (tubercles, crest)
I: lower ribs; xiphoid
N: ventral rami
A: bilateral FL trunk (sup lumbar), Respiration (pull ribcage down or tilt sacrum/pull hips up & compress ab to EXHALE)

Question 6

All of the Ab muscles function to regulate abdominal pressure by/for:

Answer 6

1. contract to increase intra-abdominal pressure
   a) force exhale
   b) defecation
   c) micturition (urinating)
   d) vomiting
   e) parturition (childbirth)
   f) stabilize vertebral column for heavy lifting
   g) vocalization
2. relax to decrease intra-abdominal pressure (inhale)