FOM 24: Muscle Fxn and Superficial Back

Question 0

Flexion/Extension

Answer 0

in a sagittal plane around a transverse axis

Question 1

ABduction/ADduction

Answer 1

in a coronal plane around an anterioposterior axis

Question 2

Rotation

Answer 2

in a horizontal (transverse plane) around a vertical axis

Question 3

Concentric contraction

Answer 3

Active muscle fibers decrease in length

Typical movement of an agonist mover - fxns to produce the desired action

Question 4

Eccentric Contraction

Answer 4

Active muscle fibers increase in length
Typical of an antagonist muscle, produces movement opposite to the agonist
*Allows for smooth, controlled movement by counteracting the force applied by the agonist muscle.

Question 5

Isometric Contraction

Answer 5

Active muscle fibers maintain same length
Typical of a Fixator muscle - stabilizes and supports and element against the pull of an agonist.
EX: scapula fixator muscles

Question 6

Synergistic contraction

Answer 6

Muscle contraction tends to produce motion around all possible axes

• Neutralizers are muscles whose contraction prevents undesireable action.
• Synergists are muscle whose contraction aides in producing desired motion while at the same time neutralizing undesired motion

Question 7

Nerve lesions

Answer 7

usually a nerve injury that either partially or completely denervates a muscle resulting in muscle weakness or complete loss of function, respectively

Question 8

Neutral position

Answer 8

point of balance in which all the motions characteristic of a joint may occur; typically involves minimal ligamentous tension, and the least muscular effort to maintain

Question 9

Muscular imbalances

Answer 9

occurs when some muscles across a joint are weakened or paralyzed

Question 10

Pectoral girdle

Answer 10

functional unit of the clavicle and scapula
*articulates with axial skeleton at the sternoclavicular (SC) joint (only bony articulation between pectoral girdle and the axial skeleton)
Can perform: Elevation/depression, protraction/retraction, superior/inferior rotation

Question 11

Glenohumeral joint

Answer 11

between the glenoid fossa of the scapula and the humeral head

Question 12

Intrinsic (deep) back muscles

Answer 12

• derived from the embryonic dorsal muscle mass
• innervated by dorsal primary rami
• Blood supply from dorsal branches of segmental arteries
• Movement of the trunk and head, and maintains posture

Question 13

Extrinsic (superficial) back muscles

Answer 13

• Derived from the embryonic ventral muscle mass
• Innervated by ventral primary rami
• Blood supply from branches of subclavian and axillary aa.
• produce movement of the upper extremity and assist in respiration

Question 14

Trapezius m. ORIGIN

Answer 14

Medial third of superior nuchal line, external occipital protuberance, ligamentum nuchae, T1-T12 spinous processes

Question 15

Trapezius m. INSERTION

Answer 15

Spine of scapula, acromian, lateral third of clavicle

Question 16

Trapezius m. ACTIONS

Answer 16

Elevates and retracts pectoral girdle, superiorly rotates and stabilizes scapula

Question 17

Trapezius m. INNERVATION

Answer 17

Spinal accessory n. (CN XI) –> motor

C3-C4 ventral rami via cervical plexus –> sensory

Question 18

Trapezius m. BLOOD SUPPLY

Answer 18

Transverse cervical a.

Question 19

Latissimus Dorsi m. ORIGIN

Answer 19

T7-L5 spinal processes, thoracolumbar fascia, dorsal sacrum, iliac crest

Question 20

Latissimus Dorsi m. INSERTION

Answer 20

Floor of intertubercular sulcus of the humerus

Question 21

Latissimus Dorsi m. ACTION

Answer 21

Extends, adducts, and medially rotates humerus. Depresses, retracts, and inferiorly rotates scapula.

Question 22

Latissimus Dorsi m. INNERVATION

Answer 22

Thoracodorsal n.

Question 23

Latissimus Dorsi m. BLOOD SUPPLY

Answer 23

Thoracodorsal a.

Question 24

Rhomboideus major m. ORIGIN

Answer 24

T2-T5 Spinous processes

Question 25

Rhomboideus major m. INSERTION

Answer 25

medial border of the scapula

Question 26

Rhomboideus major m. ACTION

Answer 26

Retracts and elevates the pectoral girdle, inferiorly rotates scapula, stabilizes scapula

Question 27

Rhomboideus major m. INNERVATION

Answer 27

Dorsal scapular n. (C5)

Question 28

Rhomboideus major m. BLOOD SUPPLY

Answer 28

Dorsal scapular a.

Question 29

Rhomboideus minor m. ORIGIN

Answer 29

C7-T1 spinous processes

Question 30

Rhomboideus minor m. INSERTION

Answer 30

Medial border of the scapula superior to Rhomboideus major m.

Question 31

Rhomboideus minor m. ACTION

Answer 31

Retracts and elevates the pectoral girdle, inferiorly rotates the scapula, stabilizes scapula

Question 32

Rhomboideus minor m. INNERVATION

Answer 32

Dorsal scapular n. (C5)

Question 33

Rhomboideus minor m. BLOOD SUPPLY

Answer 33

Dorsal scapular a.

Question 34

Levator scapulae m. ORIGIN

Answer 34

Slips from posterior tubercles of C1-C4 transverse processes

Question 35

Levator scapulae m. INSERTION

Answer 35

Superior angle of the scapula

Question 36

Levator scapulae m. ACTIONS

Answer 36

Elevates pectoral girdle, inferiorly rotates scapula, extends and laterally flexes neck

Question 37

Levator scapulae m. INNERVATION

Answer 37

C3-C4 ventral rami via cervical plexus and dorsal scapular n. (C5)

Question 38

Levator scapulae m. BLOOD SUPPLY

Answer 38

Dorsal scapular a.

Question 39

Serratus posterior superior m. ORIGIN

Answer 39

C7-T3 spinous processes

Question 40

Serratus posterior superior m. INSERTION

Answer 40

superior borders of ribs 2-5

Question 41

Serratus posterior superior m. ACTIONS

Answer 41

Elevates ribs 2-5

Question 42

Serratus posterior superior m. INNERVATION

Answer 42

Segmentally by ventral primary rami (intercostal nerves)

Question 43

Serratus posterior superior m. BLOOD SUPPLY

Answer 43

Branches of the posterior intercostal aa.

Question 44

Serratus posterior inferior m. ORIGIN

Answer 44

T11-L3 spinous processes

Question 46

Serratus posterior inferior m. INSERTION

Answer 46

Inferior borders of ribs 9-12

Question 47

Serratus posterior inferior m. INNERVATION

Answer 47

segmentally by ventral primary rami (intercostal nn.)

Question 47

Transverse cervical a.

Answer 47

originates from the thyrocervical trunk off the subclavian a. - Courses posteriorly in the neck to the levator scapulae m. - Deep to trapezius m. giving ascending and descending branches that course with branches of the spinal accessory n. (CN XI) and C3-C4 ventral rami

Question 48

Serratus posterior inferior m. BLOOD SUPPLY

Answer 48

Branches of posterior intercostal aa.

Question 49

Dorsal scapular a.

Answer 49

Arises as a branch of the transverse cervical a. (50%) or a direct branch of the subclavian a. (50%) - Courses posteriorly in the neck deep to the levator scapulae m. - Deep to the Rhomboideus major and minor mm. with dorsal scapular n.

Question 50

Thoracodorsal a.

Answer 50

From the subscapular a. (a branch of the axillary a.) - Courses with the thoracodorsal n. - Deep to the Latissimus dorsi m. (entering near humeral attachment)

Question 51

Serratus posterior inferior m. ACTION

Answer 51

depresses ribs 9-12