learning check muscles

pectoralis minor origin

originates from 3rd, 4th, and 5th ribs

pectoralis minor insertion

inserts on coracoid process of the scapula

pectoralis minor action

contraction of this muscle results in the coracoid process of the scapula being pulled towards the ribs (shoulder girdle downward rotation, or adduction)

serratus anterior origin

originates from the anterior lateral aspects of the upper nine ribs

serratus anterior insertion

inserts on the anterior surface of the vertebral (medial) border of the scapula

serratus anterior action

contraction of the muscle results in abduction (upward rotation and lateral tilt) of the shoulder girdle

levator scapulae origin

originates on the transverse processes of the first four cervical vertebrae

levator scapulae insertion

inserts on the superior aspect of the vertebral border of the scapula

levator scapulae action

contraction of this muscle results in elevation (downward rotation and adduction) of the shoulder girdle

rhomboids origin

originate on the spinous processes of the 7th cervical through 5th thoracic vertebrae

rhomboids insertion

inserts on the vertebral (medial) border of the scapula

rhomboids action

contraction of this muscle results in elevation and adduction (downward rotation) of the shoulder girdle

trapezius origin

originates on the external occipital protuberance at the base of the skull and the spinous processes of all cervical and thoracic vertebrae

trapezius insertion

inserts on the spine of the scapula and posterior surface of the clavicle

trapezius action

elevation and adduction (downward rotation) of the shoulder girdle, also assist in elevation of the shoulder girdle, and contributes to upward rotation of the shoulder girdle

pectoralis major origin

originates on the 2nd to 6th ribs, the sternum, and the medial half of the clavicle

pectoralis major insertion

inserts on the anterior area of the surgical neck of the humerus just distal to the greater tuberosity

pectoralis major action

contraction of this muscle produces flexion, adduction, and internal rotation of the shoulder joint

coracobrachialis origin

originates on the coracoid process of the scapula (where the tendon of origin is conjoined with the tendon of origin of the short head of the biceps brachii)

coracobrachialis insertion

inserts in the middle of the medial side of the humerus opposite the deltoid tubercle on the lateral side

coracobrachialis action

flexes the shoulder joint and because of its angle of pull, assists with adduction of the joint

biceps brachii long origin

originates on the supraglenoid tubercle on the superior edge of the glenoid of the scapula

biceps brachii short origin

originates on the coracoid process of the scapula (and is conjoined with the coracobrachialis tendon of origin)

biceps brachii insertion

insert on the tuberosity of the radius, which is one of the two forearm bones

biceps brachii action

contraction of this muscle at the shoulder joint include flexion and abduction by the long-head tendon and flexion, adduction, and internal rotation by the short head tendon

subscapularis origin

originates on the subscapular fossa

subscapularis insertion

inserts on the lesser tuberosity of the humerus

subscapularis action

internal rotation and flexion of the GH joint, stability of the GH joint

deltoid (anterior/clavicular) origin

originates on the lateral 1/3 of anterior border of clavicle

deltoid (anterior/clavicular) insertion

inserts on the deltoid tubercle

deltoid (anterior/clavicular) action

flexion, adduction, and internal rotation of GH joint (above horizontal abduction)

deltoid (middle/acromial) origin

originates on the lateral border of acromion process

deltoid (middle/acromial) insertion

inserts on the deltoid tubercle

deltoid (middle/acromial) action

abduction of GH joint

deltoid (posterior, scapular) origin

originates on the inferior lip of spine of scapular

deltoid (posterior, scapular) insertion

inserts on the deltoid tubercle

deltoid (posterior, scapular) action

extension, adduction, and external rotation of GH joint (above horizontal, abduction)

supraspinatus origin

originates on the supraspinatus fossa of the scapula

supraspinatus insertion

inserts on the proximal facet of greater tuberosity of humerus

supraspinatus action

abduction of GH joint, GH joint stability

infraspinatus origin

originates on the infraspinatus fossa of spine of scapula

infraspinatus insertion

inserts on the middle facet of greater tuberosity of humerus

infraspinatus action

external rotation and extension of GH joint, GH joint stability

teres minor origin

originates on the upper 2/3 of lateral border of scapula

teres minor insertion

inserts on the distal facet of greater tuberosity of humerus

teres minor action

external rotation, extension, and adduction of GH joint; GH joint stability

latissimus dorsi origin

originates on the spinous processes of lower 6 thoracic and all lumbar vertebrae, ilimu, lower 3 ribs, inferior angle of scapula

latissimus dorsi insertion

inserts on the intertubercular groove

latissimus dorsi action

internal rotation, extension, and adduction of GH joint

teres major origin

originates on the inferior 1/3 of lateral border and the inferior angle of scapula

teres major insertion

inserts beneath the lesser tuberosity on anterior humerus

teres major action

internal rotation, extension, and adduction of GH joint

brachialis origin

originates on the distal 1/3 of anterior surface of humerus

brachialis insertion

insertion coronoid process and tuberosity of ulna

brachialis action

flexion of elbow

brachioradialis origin

originates on the proximal aspect of lateral supracondylar ridge of humerus

brachioradialis insertion

inserts on the lateral aspect of styloid process of radius

brachioradialis action

flexion of elbow, supination of forearm