Intrinsic Muscles Flashcards
Deltoideus: Insertion
Insertion: deltoid tuberosity of the humerus
Deltoideus: Action
Action: flex shoulder
Name the two parts of the deltoideus.
1) scapular
2) spinal
Infraspinatus: Origin
Origin: infraspinous fossa of the scapula
Infraspinatus: Insertion
Insertion: lateral side of the greater tubercle of the humerus (small, circumscribed area)
Infraspinatus: Action
Action:
1) laterally stabilizes the shoulder
2) abduct and laterally rotate shoulder
3) assists other muscles in the extension or flexion of shoulder
There’s minor: Origin
Origin:
1) infraglenoid tubercle of the scapula
2) distal caudal border of scapula
Teres minor: Insertion
Insertion: Teres minor tuberosity of humerus
Teres minor: Action
Action:
1) laterally stabilizes for shoulder
2) laterally rotate shoulder
3) flex shoulder
Supraspinatus: Origin
Origin: supraspinous fossa of the scapula
Supraspinatus: Insertion
Insertion: greater tubercle of the humerus
Supraspinatus: Action
Action:
1) laterally stabilizes the shoulder
2) extend shoulder
Subscapularis: Origin
Origin: subscapular fossa of the scapula
Subscapularis: Insertion
Insertion: lesser tubercle of the humerus
Subscapularis: Action
Action:
1) Medially stabilizes the shoulder
2) adduct shoulder
3) extend shoulder
Teres major: Origin
Origin:
1) caudal angle and caudal border of the scapula
2) subscapularis muscle
Teres major: Insertion
Insertion: Teres major tuberosity of the humerus
Teres major: Action
Action: flex shoulder, rotate arm medially
Coracobrachialis: Origin
Origin: coracoid process of the scapula
Coracobrachialis: Insertion
Insertion: crest of the lesser tubercle of the humerus, near Teres major tuberosity
Coracobrachialis: Action
Action: mainly stabilizes the shoulder, but can assist other muscles in adduction and/or extension of shoulder
Tensor fasciae antebrachii: Origin
Origin: fascia covering the lateral surface of the latissimus dorsi muscle
Tensor fasciae antebrachii: Insertion
Insertion: olecranon of the ulna
Tensor fasciae antebrachii: Action
Action: extend elbow
Name the 4 heads of the triceps brachii.
1) long head
2) lateral head
3) medial head
4) accessory head
Triceps brachii: Origin
Origin:
1) caudal border of the scapula (LONG HEAD)
2) tricipital line
Triceps brachii: Insertion
Insertion: olecranon of ulna
Triceps brachii: Action
Action:
1) flex shoulder (LONG HEAD)
2) extend elbow
Anconeus: Origin
Origin:
1) lateral supracondylar crest of humerus
2) lateral and medial epicondyles of humerus
Anconeus: Insertion
Insertion: proximal and lateral aspect of the ulna
Anconeus: Action
Action: extend elbow
Biceps brachii: Origin
Origin: supraglenoid tubercle of the scapula
Biceps brachii: Insertion
Insertion: radial and ulnar tuberosities
Biceps brachii: Action
Action: extend shoulder and flex elbow
Brachialis: Origin
Origin: proximal and lateral aspect of the humerus
Brachialis: Insertion
Insertion: radial and ulnar tuberosities
Brachialis: Action
Action: flex elbow
Deltoideus: Origin
Origin: spine and acromial process of scapula
