Intrinsic Back Muscles

Question 1

Deep back muscles typically do the following functions?

a. Move pectoral gurdle
b. Move upper limbs
c. Maintain posture
d. Rotation
e. Both C and D

Answer 1

e.

Question 2

Extrinsic back muscles are also considered?

a. Epaxial
b. Hypaxial
c. Apaxial
d. Superficial

Answer 2

a. Epaxial

Question 2

What is the most superficial deep/intrinsic back muscle?

a. Splenius
b. Erector Spinae
c. Transversospinalis
d. Trapezius

Answer 2

a. Splenius

Question 3

Which rami typically innervate intrinsic/deep back muscles

Answer 3

Dorsal rami

Question 4

What are the groups of epaxial back muscles?

What is the muscle that is not included in these groups?

Answer 4

Erector spinae group
Transversospinalis group
Segmental group
Suboccipital group

Splenius not included (Neck)

Question 5

Which is superfical and which is deep in relation to each other?

Erector spinae group
Transversospinalis group

Answer 5

Erector spinae group - Superficial

Transversospinalis group - Deep

Question 6

Splenius cervicis/capitis

Answer 6

Bilaterally: Extend head and neck
Unilaterally: Laterally flex neck
Rotate head to side of contracting muscle

Spinal nerves (dorsal rami)

Question 7

Erector Spinae group includes what muscles?

a. Semispinalis
b. Rotatores
c. Iliocostalis
d. Longissimus
e. Multifidus
f. Spinalis

Answer 7

c, d, f

Question 8

Tranvsersospinalis group includes what muscles?

a. Semispinalis
b. Rotatores
c. Iliocostalis
d. Longissimus
e. Multifidus
f. Spinalis

Answer 8

a, b, e

Question 9

Which is middle, lateral and most medial muscles of erector spinae group?

Iliocostalis
Longissimus
Spinalis

Answer 9

Iliocostalis - Lateral
Longissimus - Middle
Spinalis - Most medial

Question 10

Erector spinae group

Answer 10

Bilaterally: Extend vertebral column & head
Unilaterally: Laterally flex vertebral column

Spinal nerves (dorsal rami)

Question 11

Semispinalis

Answer 11

Extend head, thoracic, & cervical regions
Rotates head, thoracic, & cervical regions contralaterally (Contract semispinalis muscle on left side, rotate region to right)

Spinal nerves (dorsal rami)

Question 12

Multifidus

Answer 12

Stabilizes vertebrae during localized movements of vertebral column

Dorsal rami of spinal nerves

Question 13

Rotatores

Answer 13

Extends head, thoracic, & cervical regions
Rotates regions contralaterally

Dorsal rami of spinal nerves

Question 14

Which muscles are in the Segmental muscle group?

Answer 14

Interspinales
Intertransversari
Levator costarum

Question 15

Which muscle in innervated by both the dorsal and ventral rami of spinal nerves?

a. Levator costarum
b. Interspinalis
c. Intertransversari
d. Semispinalis

Answer 15

c. Intertransversari

Question 17

Levator costarum

Answer 17

Elevates ribs

Dorsal rami of spinal nerves

Question 18

Interspinalis

Answer 18

Weak extension of spine

Dorsal rami of spinal nerves

Question 19

What muscle(s) overlay the suboccipital region of muscles?

a. Trapezius
b. Splenius
c. Semispinalis cervicis
d. Semispinalis capitis
e. Both b. and c.
f. Both b. and d.

Answer 19

f. Both b. and d.

Question 20

Suboccipital region muscles

Function & innerv

Answer 20

Postural muscles
Aid in extension & rotation at atlantoaxial joint (btw C1 and C2)

Suboccipital nerve
Dorsal rami of C1 spinal nerve

Question 21

What are the four muscles of subocciptal region?

Answer 21

Rectus capitus posterior major
Rectus capitus posterior minor
Superior oblique capitis
Inferior oblique capitis

Question 22

Intertransversari

Answer 22

Weak lateral flexion of spine

Dorsal rami of spinal nerves
Ventral rami of spinal nerves