Trunk

Question 1

External Intercostal Muscles

Answer 1

11 pairs (lateral to medial fiber direction)
O: inferior margin of rib
I: superior margin of rib below
I: intercostal nerves
A: stiffen chest wall

Question 2

Internal Intercostals

Answer 2

11 pairs (medial to lateral fiber direction)
O: inferior margin of rib
I: superior margin of rib below
I: intercostal nerves
A: anterior: inspiration, posterior: expiration

Question 3

Innermost Intercostal

Answer 3

separated from internal intercostals by intercostal nerves & vessels

Question 4

Transversus Thoracis Muscle

Answer 4

O: posterior aspect of sternum & costal cartilages of ribs 3-6
I: 2nd-5th costal cartilages
I: intercostal nerves
A: expiration

Question 5

Subcostal Muscles

Answer 5

O: internal surface of angle of rib
I: internal surface of 2-3 ribs below origin
I: intercostal nerves
A: expiration

Question 6

Innermost Complex

Answer 6

Transversus Thoracis, Innermost Intercostals, Sub Costal Muscles

Question 7

External Oblique

Answer 7

O: ribs 5-12
I: aponeurosis from linea alba, anterior half of iliac crest, pubic tubercle (inguinal ligament)
I: T7-T12 spinal nerves
A: flexion of trunk, posterior pelvic tilt, rotation of trunk to opposite side (unilateral), lateral bending of trunk (unilateral), accessory muscle of forced expiration, protect abdominal viscera, increase abdominal pressure

Question 8

Interal Oblique

Answer 8

O: thoracolumbar fascia, anterior 2/3 iliac crest, lateral 2/3 of upper portion of inguinal ligament
I: ribs 9-12, cartilage of ribs 7-9, aponeurosis that extends to the linea alba, pubic crest and pectin pubis via conjoint tendon
I: T7-T12, L1
A: flexion of trunk, rotation of trunk to same side (unilateral), lateral bending of trunk (unilateral), accessory muscle of forced expiration, protect abdominal viscera, increase abdominal pressure

Question 9

Transversus Abdominis

Answer 9

O: ribs 7-12 (costal cartilages), thoracolumbar fascia, anterior 2/3 iliac crest, lateral 1/3 inguinal ligament
I: Aponeurosis that extends to the linea alba, pubic crest & pectin pubis via conjoint tendon
I: T7-T12, L1
A: constricts abdomen, forced expiration, protect abdominal viscera, increase abdominal pressure

Question 10

Rectus Abdominus

Answer 10

O: pubic tubercle, pubic symphysis
I: ribs 5-7 (costal cartilages), xiphoid process
I: T7-T12
A: flexes trunk, posterior pelvic tilt

Question 11

Psoas Major

Answer 11

O: tranverse process L1-L5, vertebral bodies & intervertebral discs of T12-L5
I: lesser trochanter of femur
I: L2-L4 spinal nerves
A: hip flexion with origin fixed, trunk flexion with insertion fixed, lateral bending to same side (unilateral)

Question 11

Psoas Major

Answer 11

O: tranverse process L1-L5, vertebral bodies & intervertebral discs of T12-L5
I: lesser trochanter of femur
I: L2-L4 spinal nerves
A: hip flexion with origin fixed, trunk flexion with insertion fixed, lateral bending to same side (unilateral)

Question 12

Psoas Minor

Answer 12

O: T12-L1 vertebral bodies and intervertebral discs
I: pecten pubis, ilium
I: L1
A: (weak muscle) flexion of trunk

Question 13

Iliacus

Answer 13

O: superior 2/3 of iliac fossa, inner lip of iliac crest, anterior sacroiliac ligaments & iliolumbar ligaments, lateral aspect of sacrum
I: lesser trochanter of femur & shaft below lesser trochanter
I: L2-L3 femoral nerve
A: hip flexion

Question 14

Quadratus Lumborum

Answer 14

O: inner lip of iliac crest, iliolumbar ligament
I: 12th rib, transverse processes of L1-L4
I: T12-L3
A: extension of lumbar spine, fixes diaphragm during inspiration, lateral bending of lumbar spine to same side, fixation & depression of 12th rib