G3 Back Muscles EXAM1

Question 1

What are the Epaxial muscles? Innervation?

Answer 1

Muscles that are innervated by the Dorsal/Posterior Rami

-INTRINSIC Back Muscles

Question 2

What are Hypaxial muscles? Innervation?

Answer 2

Muscles that are innervated by the Ventral/Anterior Rami

-EXTRINSIC Back Muscles

Question 3

What are INTRINSIC back muscles? What are they classified by because of innervation? What innervates them?

Answer 3

“True back muscles”
Located in the back- act on the back
-EPAXIAL (innervated by Posterior Rami)

Question 4

What are EXTRINSIC back muscles? What are they classified by because of innervation? What innervates them?

Answer 4

HYPAXIAL muscles (innervated by Anterior Rami)

-Located on back but act on body wall and Limbs

Question 5

What muscle groups are innervated by anterior rami? Posterior rami?

Answer 5

AR- (Extrinsic) -Superficial and Intermediate back muscles

PR- (Intrinsic) - Deep back muscles (vert-vert; vert-skull)

Question 6

What are the three parts of the skull needed for this unit?

Answer 6

Superior nuchal line- farther from foremen magnum
Inferior nuchal line- closer to FM
Mastoid process of temporal bone

Question 7

What are the 7 Extrinsic muscles of the back? What is it termed embryologically? What are they innervated by?

Answer 7

7 EXTRINSIC HYPAXIAL MUSCLES

1. Trapezius (CNXI Axillary Nerve)
2. Latissimus Doris (Thoracodorsal Nerve)
3. Lavatory Scapular (Dorsal Scapular Nerve C3,C4,C5)
4. Rhomboid Major (Dorsal Scapular Nerve C5)
5. Rhomboid Minor (Dorsal Scapular Nerve C4,C5)
6. Serratus Posterior Superior (intermediate)
7. Serratus Posterior Inferior (intermediate)

ANTERIOR RAMUS

Question 8

What are the 11 Intrinsic muscles of the back? What termed? What innervated by?

Answer 8

INTRINSIC EPAXIAL MUSCLES

1. Splenius Capitis
2. Splenius Cervicis
3. Spinalis
4. Longissimus
5. Iliocostales
6. Semispinalis
7. Multifidus
8. Rotatores
9. Lavatory Costarum
10. Intertransversarii
11. Interspinalis

POSTERIOR RAMUS

Question 9

Which muscle has a unilateral contraction that causes a contralateral rotation?

Answer 9

Multifidus

Question 10

What muscle connects transverse process to transverse process?

Answer 10

Intertransversarii

Question 11

What muscle connects SPINOUS process to SPINOUS processes?

Answer 11

Interspinalis

Question 12

Spinalis, Longissimus, and Iliocostalis make up what group?

Answer 12

Erector Spinae Group

Question 13

Semispinalis, Multifidus, Rotatores makes up what group? What type of movement do they do?

Answer 13

Transversospinal group

Contralateral rotation because

Question 14

What are the actions of each of the muscles of the suboccipital triangle?

Answer 14

obliquus Capitis inferior- ipsilateral rotates head
oc superior- extension ipsilateral rotates head
RCPM- extension ipsilateral rotates head