Anatomy - intrinsic shoulder and elbow-moving muscles

Question 1

what is the origin, insertion, action and innervation of the deltoideus muscle

Answer 1

- origin: spine and acromial process of the scapula
- insertion: the deltoid tuberosity of humerus
- action: flex the shoulder
- innervation: axillary nerve

Question 2

what is the origin, insertion, action and innervation of the infraspinatus muscle

Answer 2

- origin: infraspinous fossa
- insertion: lateral side of the greater tubercle of the humerus
- action: extend or flex the joint, depending on degree of extension or position when the muscle contracts. abduct the shoulder
- innervation: suprascapular nerve

Question 3

what is the origin, insertion, action and innervation of the teres minor

Answer 3

- origin: infraglenoid tubercle and distal third of caudal border of scapula
- insertion: teres minor tuberosity of humerus
- action: flex shoulder, rotate shoulder laterally, prevent medial rotation
- innervation: axillary nerve

Question 4

what is the origin, insertion, action and innervation of the supraspinatus muscle

Answer 4

- origin: supraspinous fossa
- insertion: greater tubercle of the humerus by a thick tendon
- action: extend and stabilize shoulder joint
- innervation: suprascapular nerve

Question 5

what is the origin, insertion, action and innervation of the subscapularis muscle

Answer 5

- origin: subscapular fossa
- insertion: the lesser tubercle of the humerus
- action: adduct, extend shoulder joint
- innervation: subscapular nerve

Question 6

what is the origin, insertion, action and innervation of the teres major muscle

Answer 6

- origin: caudal border of the scapula; caudal surface of subscapularis
- insertion: teres major tuberosity of humerus
- action: flex shoulder joint
- innervation: axillary nerve

Question 7

what is the origin, insertion, action and innervation of the long head of the triceps brachii

Answer 7

- origin: caudal border of scapula
- insertion: olecranon tuber
- action: extend elbow joint and flex shoulder joint
- innervation: radial nerve

Question 8

what is the origin, insertion, action and innervation of the lateral head of the triceps brachii

Answer 8

- origin: tricipital line of humerus
- insertion: olecranon tuber
- action: extend elbow joint
- innervation: radial nerve

Question 9

what is the origin, insertion, action and innervation of the accessory head of the triceps brachii

Answer 9

- origin: neck of humerus
- insertion: olecranon tuber
- action: extend elbow joint
- innervation: radial nerve

Question 10

what is the origin, insertion, action and innervation of the medial head of the triceps brachii

Answer 10

- origin: crest of lesser tubercle near the teres major tuberosity
- insertion: olecranon
- action: extend elbow joint
- innervation: radial nerve

Question 11

what is the origin, insertion, action and innervation of the biceps brachii muscle

Answer 11

- origin: supraglenoid tubercle
- insertion: ulnar and radial tuberosities
- action: flex the elbow joint and extend the shoulder joint
- innervation: musculocutaneous nerve

Question 12

what is the origin, insertion, action and innervation of the brachialis muscle

Answer 12

- origin: proximal third of the lateral surface of the humerus
- insertion: ulnar and radial tuberosities
- action: flex elbow joint
- innervation: musculocutaneous nerve