Module 5 muscles

Question 1

Pectoralis Major origin and insertion

Answer 1

O: medial 1/2 of the clavicle, the sternum, and the costal cartilages of ribs 1-6

I: crest of the greater tubercle of the humerus

Question 2

Pectoralis Major actions

Answer 2

All fibers adduct and medially rotates the shoulder at the glenohumeral joint

Upper fibers: flex and horizontally adducts the shoulder at the GH jt

Lower Fibers:extend the shoulder at the gh jt

Question 3

Pectoralis major nerve

Answer 3

Upper fibers: lateral pectoral nerve
Lower fibers: medial and lateral pectoral nerves

Question 4

Quadratus Lumborum (QL) origin and insertion

Answer 4

O: posterior iliac crest

I: 12th rib and the transverse processes of the 1st through 4th lumbar vertebrae

Question 5

Quadratus Lumborum actions

Answer 5

The QL elevates(laterally tilts) the pelvis at the lumbosacral jt

Extends and laterally flexes the vertebral column at the spinal joints

Fixes the 12th rib during forced inhalation and exhalation

Question 6

Quadratus Lumborum nerve

Answer 6

Lumbar plexus

Question 7

External and Internal intercostal origin and insertion

Answer 7

O: inferior border of the rib above

I: superior border of rib below

Question 8

External and internal intercostal actions

Answer 8

External draw ribs superiorly increasing the space of the thoracic cavity to assist with inhalation

Internal draw ribs inferiorly decreasing the space of the thoracic cavity to assist with exhalation

Question 9

External and internal intercostals nerve

Answer 9

Thoracic nerves

Question 10

Rectus Abdominis O and I

Answer 10

O: pubic crest and pubic symphysis

I: cartilages of ribs 5-7 and the xiphoid process

Question 11

Rectus Abdominis actions

Answer 11

Flexes the vertebral column at the spinal joints

Posteriorly tilts the pelvis at the lumbosacral joint

Question 12

Rectus Abdominis nerve

Answer 12

Ventral Rami of T5-T12

Question 13

External Abdominal Oblique O/I
(Coat pocket muscle)

Answer 13

O: external surfaces of 5th through 12th ribs

I: anterior part of iliac crest, Rectus sheath to linea alba

Question 14

External abdominal oblique actions

Answer 14

Flexes and laterally flexes the vertebral column
Rotates the vertebral column to the opposite side and compresses the abdominal contents

Question 15

External abdominal oblique nerve

Answer 15

T5- T12 nerve

Question 16

Internal abdominal oblique o/i

Answer 16

O: lateral inguinal ligament, iliac crest, thoracolumbar fascia

I: internal surface of lower three ribs, Rectus sheath to linea alba

Question 17

Internal abdominal oblique actions

Answer 17

Flexes, laterally flexes, and rotates the vertebral column to the same side and compresses abdominal contents

Question 18

Internal abdominal oblique nerve

Answer 18

Ventral rami of T7-T12,
Iliohypogastric and ilioinguinal nerves

Question 19

Diaphragm o/i

Answer 19

O: inner surfaces of the lower 6 ribs and xiphoid process of the sternum, and the upper 2-3 lumbar vertebrae

I: central tendon of the diaphragm (located in the center of the muscle)

Question 20

Diaphragm actions

Answer 20

Draws down the central tendon and increases the volume of the thoracic cavity, which allows the lungs to expand for inspiration

Question 21

Diaphragm nerve

Answer 21

Phrenic nerve (“C3,C4,C5 keeps the diaphragm alive”)

Question 22

Iliopsoas o/i

Answer 22

O: iliac fossa (iliacus), bodies and transverse processes of lumbar vertebrae (psoas major)

I: lesser trochanter of the femur

Question 23

Iliopsoas actions

Answer 23

The psoas major flexes and laterally flexes the trunk at the spinal joints

Both flex, laterally rotate the hip at the coxal joint and anteriorly tilt the pelvis

Question 24

Iliopsoas nerve

Answer 24

Branches from L1-L4