Superficial Back

Question 1

Latissimus Dorsi

Answer 1

Innervation: Thoracodorsal nerve

Blood Supply: Thoracodorsal artery

Origin: spinous processes of T7-T12, L1-L5, and sacrum, ribs 9-12

Point of Insertion: Intertubercular groove of humerus

Action: medial rotation, adduction, extension, and respiration

Question 2

Trapezius

Answer 2

Innervation: Accessory nerve

Blood Supply: Transverse cervical artery

Origin: occipital bone; ligamentum nuchae; spinous processes of T-01-T12

Point of Insertion: Lateral third of clavicle, acromion and scapular spine of scapula

Action: Rotation, retraction, elevation, and depression of scaupla, levitate clavicle; extends neck, and stabilizes shoulder.

Question 3

Teres Major

Answer 3

Innervation: Lower subscapular nerve (C05, C06)

Blood Supply: Circumflex scapular artery

Origin: Inferior Angle of the scapula

Point of Insertion: Intertubercular groove of humerus

Action: Extension, adduction, and medial rotation of the humerus

Question 4

Teres Minor

Answer 4

Innervation: Axillary nerve (C05, C06)

Blood Supply: Circumflex scapular artery

Origin: Lateral border of scapula

Point of Insertion: Greater tuberosity of humerus

Action: Lateral rotation of humerus, protect and stabilizes shoulder joint

Question 5

Infraspinatus

Answer 5

Innervation: Suprascapular nerve (C05, C06)

Blood Supply: Suprascapular artery and circumflex scapular artery

Origin: Infraspinatus fossa on posterior surface of scapula

Point of Insertion: Greater tubercle of humerus

Action: Laterally rotates upper limb; stabilizes glenohumeral joint

Question 6

Supraspinatus

Answer 6

Innervation: Suprascauplar nerve

Blood Supply: Suprascapular artery

Origin: Supraspinatus fossa

Point of Insertion: Greater tubercle of humerus

Action: assist deltoid in abducting arm, stabilizes glenohumeral joint

Question 7

Deltoid

Answer 7

Innervation: axilliary nerve

Blood Supply: posterior circumflex humeral artery

Origin: lateral third of clavicle, acromion, and scapular spine

Point of Insertion: deltoid tuberosity of lateral side of body of humerus

Action: flexion and medial rotation of humerus, abduction of humerus, and extension and lateral rotation of humerus

Question 8

Rhomboid major

Answer 8

Innervation: dorsal scapular nerve

Blood Supply: dorsal scapular artery

Origin: Spinous processes T2-T5

Point of Insertion: Medial border of scapula below scapular spine

Action: steadies scapula, moves inferior angle backwards and up

Question 9

Rhomboid minor

Answer 9

Innervation: dorsal scapular nerve

Blood Supply: dorsal scapular artery

Origin: spinous processes of C7-T1

Point of Insertion: Medial border of scapula above scapular spine

Action: Steadies scapula, moves inferior angle back and up

Question 10

Serratus posterior inferior muscle

Answer 10

Innervation: Intercostal nerves 9-12

Blood Supply: Intercostal arteries

Origin: supraspinal ligament and l1-l3, t11-t12

Point of Insertion: Lower borders of ribs 9-12

Action: draws lower ribs backwards and upwards

Question 11

Serratus posterior superior muscle

Answer 11

Innervation: intercostal nerves 2-5

Blood Supply: Intercostal arteries

Origin: supraspinal ligament, ligamentum nuchae, T1-T3, C7

Point of Insertion: upper borders of ribs 2-5

Action: Elevates upper ribs

Question 12

Long head of the triceps brachii muscle

Answer 12

Innervation: Radial nerve

Blood Supply: Deep brachail artery

Origin: Posterior surface of body of humerus

Point of Insertion: Olecranon of ulna

Action: Extends forearm at elbow

Question 13

Levator Scapulae

Answer 13

Innervation: Dorsal scapular nerve and direct branches from spinal nerves C03, C04

Blood Supply: Dorsal scapular artery

Origin: transverse processes of the atlas and axis, as well as the posterior tubercles of the 3rd-4th cervical vertebrae.

Point of Insertion: superior angle and medial border of the scapula

Action: lift scapulae