SDL: Muscles of the Back

Question 1

Innervation of the Extrinsic (superficial) muscles of the back?

Answer 1

Ventral rami of spinal nerves

Accessory nerve

Question 2

What are the extrinsic muscles of the back?

Answer 2

Superficial group:

• Rhomboid major and minor
• Levator Scapuale
• Trapezius
• Latissimus Dorsi

Intermediate group:

• Serratus posterior superior
• Serratus Posterior inferior

Question 3

Function of the extrinsic muscles of the back?

Answer 3

Weak accessory muscles for respiration

some scapular movements

Question 4

Innervation of the Intrinsic (deep) muscles of the back?

Answer 4

Posterior rami of spinal nerves

Question 5

What muscles are in the superficial Intrinsic group?

Answer 5

Superficial group: (Splenius Muscles)
- Splenius Capitus
- Splenius Cervicis
responsible for head movements

Question 6

What muscles are in the intermediate Intrinsic group?

Answer 6

Intermediate group: (Erector Spinae Muscles)
- Spinalis
- Longissimus
- Iliocostalis
principal extensor of the vertebral column

Question 7

What Muscles are in the Deep Intrinsic group?

Answer 7

Deep group:
 - semispinalis
 - multifidis
 - rotares
rotation and extension of the vertebral column