Scalene Muscles

Question 1

Anterior Scalene

Answer 1

O: transverse processes of third and sixth cervical vertebrae

I: first rib

A: fixation / elevation of first rib during inhalation.
- with fixed rib, then action is lateral flexion of neck

In: ventral rami of cervical spinal nerves at origin of muscle

Question 2

Middle Scalene

Answer 2

O: transverse processes of lower five or six cervical vertebrae, possibly atlas

I: first rib

A: fixation / elevation of first rib during inhalation.
- with fixed rib, then action is lateral flexion of neck

In: ventral rami of cervical spinal nerves at origin of muscle

Question 3

Posterior Scalene

Answer 3

O: transverse processes of fifth and sixth cervical vertebrae

I: second rib

A: fixation / elevation of second rib during inhalation

In: ventral rami of cervical spinal nerves at origin of muscle