Mastering A&P: Arm Muscles

Which of the following is NOT supported by the appendicular musculature?

breathing movements True: stabilization of the pectoral girdle stabilization of the pelvic girdle movement of the upper and lower limbs

The origins of the triceps brachii are the superior, lateral margin of the humerus; the infraglenoid tubercle of the scapula; and the posterior surface of the humerus, and the insertion is the olecranon of the ulna. What is the action of this muscle?

extension at the elbow

The rotator cuff is a term used to describe the group of muscles and tendons that stabilize and reinforce the __________.

glenohumeral joint

All the tendons of the rotator cuff muscles combine at which location?

humeral head

The origin of the long head of the triceps brachii is on the __________.

infraglenoid tubercle of the scapula lateral and medial heads origin: posterior shaft of humerus ALL insertion: olecranon process of ulna

The two heads of the biceps brachii muscle come together distally to insert on the __________.

insertion: radial tuberosity long head origin: supraglenoid tubercule of scapula short head origin: coracoid process of the scapula

The muscle that can extend, adduct, and medially rotate the shoulder is (the) ________.

latissimus dorsi

Which major muscle largely opposes the actions of the pectoralis major?

latissimus dorsi

pectoral girdle muscles (anterior)

levator scapulae, trapezius, subclavius, pectoralis minor, serratus anterior

Which intrinsic muscle(s) of the hand flexes the metacarpophalangeal joints, and also produces extension at the proximal and distal interphalangeal joints?

lumbricals

Which movement is not associated with the scapula?

opposition true:protraction, depression, elevation

latissimus dorsi

origin: thoracic and lumbar vertebrae spinous processes, ribs (8-12), and posterior lip of iliac crest via Thoracolumbar Fascia insertion: intertubercular groove of humerus action: adduct arm, extension, medial rotation

The muscles that extend the forearm are located __________.

posteriorly

The lesser tubercle of the humerus is the insertion point for the ________ muscle.

subscapularis

The origins of the levator scapula are from the ___________ of four cervical vertebrae.

transverse processes insertion: medical border of scapula action: elevates, pulls glenoid cavity inferiorly

The diamond-shaped ________ muscle originates on the middle of the neck and back, and inserts on the clavicles and scapular spines, covering the upper back and extending to the base of the skull.

trapezius

Infraspinatus muscle

(Rotator Cuff Muscle) origin: infraspinous fossa of the scapula inserts: humerus action: adduction and lateral rotation of arm

teres minor

(Rotator Cuff Muscle) origin: lateral border of the scapula insertion: greater tubercule of the humerus action: rotates arm laterally, adducts

supraspinatus muscle

(Rotator cuff muscles) origin: supraspinous fossa of scapula insertion: greater tubercle of humerus action: abducts the arm at the shoulder

The subscapularis muscle inserts on the greater tubercle and laterally rotates the humerus (T/F)

False origin: subscapular fossa of scapula insertion: lesser tubercule of humerus action: medially rotates arm

Serrarus Anterior

Origin: frontal ribs (1-8) Insertion: anterior/ medial surface of scapula Movement: lateral/upward rotation abduction of scapula

muscles that move the arm

Pectoralis major, latissimus dorsi, deltoid, supraspinatus, infraspinatus, subscapularis, teres major, teres minor, trcipes brachii long head

The triceps brachii muscle is opposed in extension of the elbow by the antagonistic muscle, ________.

brachialis

Which of the following muscles is not part of the shoulder?

brachialis true: infraspinatus supraspinatus subscapularis

The muscle that generates the most power during elbow flexion is the __________.

brachialis (50% more power than biceps brachii)

The brachialis muscle is located __________ to the biceps brachii muscle.

deep brachialis origin: anterior surface of humerus insertion: tuberosity and coranoid process of ulna action: flexes arm at elbow

Of the nine muscles that cross the shoulder joint and insert on the humerus, which muscle is considered to be a prime mover?

deltoid, pectoralis major, latissimus dorsi

deltoid

origin: lateral clavicle and scapula insertion: deltoid tuberosity of humerus

Which movement results after the contraction of the serratus anterior muscle?

scapular protraction and rotation

The prime mover of elbow extension is the __________.

triceps brachii

If the pectoral nerves were damaged, which of the following would NOT be an effect seen as a result of paralysis of pectoralis major?

weakened extension at the shoulder True: weakened flexion, medial rotation, or adduction at the shoulder

The teres major adducts the arm but does not __________ the arm.

abduct origin: lateral border of the scapula insertion: intertubercular groove of the humerus action: medially rotate, extend, and adduct arm

The smallest of the posterior extensors of the elbow joint is the __________.

aconeus origin: lateral epicondyle of humerus insertion: olecranon process of ulna

Which of the following motions is the deltoid INCAPABLE of performing?

adduction of the shoulder joint True: lateral rotation abduction of shoulder junction flexion of humerus

The action that moves the scapula towards the head is called __________.

elevation