Unit 1 Exam - Extrinsic Back

Question 1

Trapezius muscle

Answer 1

Proximal attachment: superior nuchal line, external occipital protuberance, nuchal ligament, spinous process of C7 and all thoracic vertebrae

Distal attachment: lateral clavicle, acromion, spine of scapula

Primary actions: assists in rotation of scapula during abduction of humerus above the horizontal; upper fibers elevate, middle fibers retract (adduct), and lower fibers depress scapula

primary innervations: cranial nerve 11 & C3, C4 for proprioception

Question 2

Latissimus dorsi muscle

Answer 2

Proximal attachment: spinous process of lower thoracic and all lumbar vertebrae, sacrum, iliac crest, lower ribs

distal attachment: intertubercular sulcus of humerus

primary actions: extends, adducts, & medially rotates humerus

innervations: thoracodorsal n (C6, C7, C8)

Question 3

Levator scapulae muscle

Answer 3

proximal attachment: transverse processes of upper cervical vertebrae

distal attachment: superior angle of scapula

primary actions: elevates scapula, downward rotation of scapula

innervation: dorsal scapular n (C5), & C3, C4

Question 4

Rhomboid major muscle

Answer 4

proximal attachment: spinous processes of upper thoracic vertebrae

distal attachment: medial border of scapula

primary actions: retracts (adducts) and elevates scapula

innervations: dorsal scapular n (C5)

Question 5

Rhomboid minor muscle

Answer 5

proximal attachment: lower portion of nuchal ligament, spinous processes of C7-T1

distal attachment: medial border of scapula

primary actions: retracts (adducts) and elevates scapula

innervations: dorsal scapular n (C5)

Question 6

Serratus posterior superior muscle

Answer 6

proximal attachment: nuchal ligament, spinous processes of lower cervical and upper thoracic region

distal attachment: upper ribs

primary actions: elevate upper ribs

innervations: ventral/anterior rami of upper thoracic nerves

Question 7

Serratus posterior inferior

Answer 7

proximal attachment: spinous processes of lower thoracic and upper lumbar region

distal attachment: lower ribs

primary actions: depress lower ribs

innervations: ventral/anterior rami of lower thoracic nerves