Question 1

Which embryonic structure gives rise to both epaxial and hypaxial muscles of the torso?

Accepted Answer

Somite \u003e Myotome

Question 2

Epaxial muscles are innervated by which branch of the spinal nerve?

Accepted Answer

Dorsal (posterior) ramus

Question 3

Which of the following is the correct order of the three major layers of axial muscles from superficial to deep?

Accepted Answer

Superficial, middle, deep

Question 4

The erector spinae group consists of which three muscles?

Accepted Answer

Iliocostalis, Longissimus Dorsi, Spinalis

Question 5

What is the bilateral action of the erector spinae muscles?

Accepted Answer

Extend the vertebral column

Question 6

If a patient has weakness in lateral flexion of the vertebral column to one side, which muscle group is most likely affected?

Accepted Answer

Erector spinae (unilateral action)

Question 7

Which muscle is the lateral-most group of the erector spinae?

Accepted Answer

Iliocostalis

Question 8

A lesion to the dorsal ramus of a spinal nerve would most directly affect which muscle group?

Accepted Answer

Epaxial muscles

Question 9

Which muscle originates from the spinous processes of C5-T2 and inserts on the spinous processes of C2?

Accepted Answer

Spinalis cervicis

Question 10

During a back extension exercise, which muscle group is primarily responsible for the movement?

Accepted Answer

Erector spinae

Question 11

Which of the following best describes the anatomical position of epaxial muscles relative to the transverse process of the vertebra?

Accepted Answer

Dorsal (posterior) to the transverse process

Question 12

If the longissimus dorsi muscle is damaged, which action would be most affected?

Accepted Answer

Extension and rotation of the head to the same side

Question 13

Which muscle group is found medial-most in the erector spinae?

Accepted Answer

Spinalis

Question 14

A patient presents with difficulty extending their vertebral column. Which nerve branch is most likely compromised?

Accepted Answer

Dorsal ramus of spinal nerve

Question 15

Which of the following is NOT a member of the erector spinae group?

Accepted Answer

Multifidus

Question 16

Which muscle group is responsible for unilateral lateral flexion of the vertebral column?

Accepted Answer

Erector spinae

Question 17

Which of the following statements about the origins and insertions of spinalis cervicis is correct?

Accepted Answer

Originates from spinous processes of C5-T2 and inserts on spinous processes of C2

Question 18

Which muscle group is located deep to the scapula and is responsible for extending the vertebral column?

Accepted Answer

Erector spinae

Question 19

Which of the following best describes the function of the erector spinae muscles during unilateral contraction?

Accepted Answer

Lateral flexion of the vertebral column to the same side

Question 20

Which muscle group would be most active during a movement that requires both extension and lateral flexion of the vertebral column?

Accepted Answer

Erector spinae

Axial Musculature: Epaxial and Hypaxial Muscles of the Torso

Study Guide - Practice Questions