Superficial Extrinsic Back Mucles

Question 0

Superficial Posterior Axiopendicular Muscles

Answer 0

Trapezius, latissimus dorsi

Question 1

Superficial

Answer 1

trapezius, latissimus dorsi, levator scapulae, rhomboids (major and minor)

Question 2

Trapezius

Answer 2

• direct attachment of pectoral girdle to trunk

- attaches pectoral girdle to the cranium and vertebral column and assists in suspending the upper limb

Question 3

Trapezius- 3 parts

Answer 3

Descending (superior part)- elevates scapula
Middle Part- retracts the scapula, pulls it posterorly
Ascending (inferior part)- depresses scapula and lowers shoulder

Descending ascending work together in rotating scapula towards thoracic wall

Question 4

Trapezius (Medial attachment)

Answer 4

Medial attachment- medial third of superior nuchal line; external occipital protuberance; nuchal ligament; spinouus process of C7-T12

Question 5

Trapezius (lateral attachment)

Answer 5

lateral attachment- lateral third of clavicle; acromion and spine of scapula

Question 6

Trapezius (Innervation)

Answer 6

innervation- spinal accessory nerve (CN X1) (motor fibers) and C3, C4 (pain and proprioception fibers)

Question 7

Trapezius ( Main actionss)

Answer 7

Main actions of trapezius- descending (superior) part elevates; ascending (inferior part) depresses; and middle part (or all parts together) retract scapula; descending and ascending parts act together to rotate glenoid cavity superiorly

Question 8

Latissimus Dorsi

Answer 8

• large fan shaped muscle that covers wide area of back
• pases fromtrunk to the humerus and acts directly on the glenohumeral (shoulder) joint and indirectlyon pectoral girdle(scapulathoracic joint)
• raises trunk of arm

Question 9

Latissimus dorsi (Medial Attachment)

Answer 9

-medially attaches to spinous processes of inferior 6 thoracic vertebrae , thoracolumbar fascia, iliac crest, and inferior 3 or 4 ribs

Question 10

Latissimus Dorsi (lateral attachment)

Answer 10

-laterally attaches to the floor of intertubercular sulcus (groove) of humerus

Question 11

Latissimus Dorsi (innervation)

Answer 11

Thoracodorsal nerve (C6, C7, C8)

Question 12

Latissimus Dorsi (Main actions)

Answer 12

extends, adducts, and medially rotates humerus; raises body toward arm during climbing

Question 13

Deep Posterior Axiopendicular Muscles

Answer 13

Levator scapulae and Rhomboids

Question 14

Levator Scapulae

Answer 14

• superior 1/3 lies deep to SCM; the inferior third is deep to the trapezius
• acts with superior portion of trapezius to elevate the scapula
• with rhomboids and pectoralis minor the levator scapulae rotates the scapula
• acting bilaterally: they extend the neck
• acting unilaterally: contributes to lateral flexion of neck

Question 15

Levator Scapulae (Medial Attachment)

Answer 15

Medially attaches to posterior tubercles of transverse processes of C1- C4

Question 16

Levator Scapulae (lateral attachment)

Answer 16

Laterally attaches to the medial border of scapula superior to root of spine

Question 17

Levator Scapulae (Innervation)

Answer 17

Dorsal scapular (C5) ad cervical (C3 and C4) nerves

Question 18

Levator Scapulae (main actions)

Answer 18

elevates scapula and tilts its glenoid cavity inferiorly by rotating scapula

Question 19

Rhomboids (Major and Minor)

Answer 19

-deep to trapezius form parallel bands that pass inferolaterally from vertebrae to the medial border of the scapulae
Rhomboid Major- thin flat and 2x’s wider than the thicker Rhomboid Minor lying superior to it
-retract and rotate the scapula

Question 20

Rhomboid Minor (Medial attachment)

Answer 20

nuchal ligament; spinous process of C7 and T1 vertebrae

Question 21

Rhomboid Minor (Later attachment)

Answer 21

rhomboid minor laterally attaches to the triangular area at medial end of scapular spine

Question 22

Rhomboid Major (Medial attachment)

Answer 22

Rhomboid major medially attaches to the spinous proceses of T2- T5 vertebrae

Question 23

Rhomboid Major (lateral attachment)

Answer 23

rhomboid major laterally attaches to the medial border of scapula from level of spine inferior to angle

Question 24

Rhomboid (Innervation)

Answer 24

Dorsal Scapular Nerve (C4,C5)

Question 25

Rhomboid (Main Actions)

Answer 25

retract scapula and rotate it to depress glenoid cavity; fix scapula to thoracic wall