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Question 1

Extrinsic muscles (hypaxial)

Answer 1

• Move the limbs

- Innervated by CN1 (accessory nerve) or branches of the brachial plexus (ventral rami and spinal nerves)

Question 2

Intrinsic muscles (epaxial)

Answer 2

• Support upright posture and allow movements of the vertebral column
• Involved in proprioception
• Innervated by the dorsal rami of spinal nerves

Question 3

Trapezius

Answer 3

• Action: Elevates, depresses, and retracts the scapulae, and rotates the glenoid fossa superiorly
• Innervation: Accessory nerve (motor), and the ventral rami of C3 and C4 (sensory)

Question 4

Latissimus dorsi

Answer 4

• Action: Extends, adducts, and medially rotates the humerus; raises the torso towards arms during climbing
• Innervation: Thoracodorsal nerve

Question 5

Rhomboid major and minor

Answer 5

• Action: Retract, elevate, and rotate scapulae downwards, as well as fix it to the thoracic wall
• Innervation: Dorsal scapular nerve (C3 and C4 motor)

Question 6

Levator scapulae

Answer 6

• Action: Elevates the scapulae and tilts glenoid fossa inferiorly (downward rotation)
• Innervation: Dorsal scapular nerve and ventral rami of cervical nerves

Question 7

Serratus posterior superior

Answer 7

• Action: Elevate the ribs

- Innervation: T2-T5 intercostal nerves (ventral rami)

Question 8

Serratus posterior inferior

Answer 8

• Action: Depresses ribs

- Innervation: Intercostal and subcostal nerves (ventral rami)

Question 9

Splenius cervicis and capitis

Answer 9

• Action: Extend head and neck (bilaterally), laterally flex neck and rotate head to side of contracting muscle (unilaterally)
• Innervation: Dorsal rami of spinal nerves

Question 10

Erector spinae group: Iliocostalis, longissimus, and spinalis

Answer 10

• Action: Extend vertebral column and head (bilaterally), laterally flex vertebral column (unilaterally)
• Innervation: Dorsal rami of spinal nerves

Question 11

Semispinalis

Answer 11

• Action: Extend head, thoracic, and cervical regions; rotates them contralaterally
• Innervation: Dorsal rami of spinal nerves

Question 12

Multifidus

Answer 12

• Action: Stabilizes vertebrae during localized movements of vertebral column
• Innervation: Dorsal rami of spinal nerves

Question 13

Rotatores

Answer 13

• Action: Extend head, thoracic, and cervical regions; rotates them contralaterally
• Innervation: Dorsal rami of spinal nerves

Question 14

Interspinales

Answer 14

• Action:

- Innervation: Dorsal rami of spinal nerves

Question 15

Intertransversari

Answer 15

• Action:

- Innervation: Dorsal and ventral rami of spinal nerves

Question 16

Levator costarum

Answer 16

• Action:

- Innervation: Dorsal rami of C8-T11 spinal nerves