12.1 Muscles of the Superficial and Intermediate Back

Question 1

Identify the Trapezius m, its attachments, innervation, and function.

Answer 1

-Attachments:
Descending Part: Occipital bone/C1-C7 to lateral third of clavicle.
Transverse Part: T1-T4 to Acromion.
Ascending Part: T5-T12 to Scapular Spine.
-Innervation: Spinal Accessory Nerve (CN XI)
-Function: Rotate and Adduct the scapula.

Question 2

Identify and Describe the Nuchal ligament.

Answer 2

Extends from external occipital protuberance to spinous processes of cervical vertebrae.

Question 3

Identify the Latissimus dorsi muscle, its attachments, innervation, and function.

Answer 3

• Attachments: Vertebral, Scapular, Costal, and Iliac origins all insert onto the Crest of the Lesser tuberosity of the humerus.
• Innervation: Thoracodorsal n. (C6-C8).
• Function: Adducts, internally rotates and extends the brachium. Depresses the scapula.

Question 4

Identify and describe the Thoracolumbar fascia.

Answer 4

deep investing membrane which covers the deep muscles of the back of the trunk

Question 5

Identify the Accessory nerve (CN XI)

Answer 5

Located in NVA bundle underneath trapezoid.

Question 6

Identify the transverse cervical artery. From where does this branch?

Answer 6

It runs along deep surface of the trapezius and is a branch of the thyrocervical trunk.

Question 7

Identify the levator scapulae muscle, its attachments, innervation, and function.

Answer 7

• Attachments: medially to posterior tubercle of transverse processes of C1-C4; laterally to medial border of scapula
• Action: elevate scapula and tilt glenoid cavity inferiorly
• Innervation: dorsal scapular n. (C5) and cervical nn. (C3 & C4)

Question 8

Identify the rhomboid minor and major muscles, their attachments, function, and innervation.

Answer 8

• Minor’s attachments: medially to nuchal ligament, spinous processes of C7 and T1; laterally to medial end of scapula’s spine
• Major’s attachments: medially to spinous processes of T2-T5; laterally to medial border of scapula
• Action (both): retract and rotate scapula, fix scapula to thoracic wall
• Innervation (both): dorsal scapular n. (C4-C5)

Question 9

Identify the serratus posterior superior muscle, its attachments, function, and innervation.

Answer 9

• Attachments: medially to nuchal ligament, spinous processes of C7-T3; laterally to superior borders of ribs 2-4
• Action: elevates ribs
• Innervation: intercostal nerves 2-5

Question 10

Identify the serratus posterior inferior muscle, its attachments, function, and innervation.

Answer 10

• Attachments: medially to spinous processes of T11-L2; laterally to inferior border of ribs 8-12 near angle
• Action: depresses ribs
• Innervation: intercostal nn. 9-11 and subcostal n.