24: UE Myology: Brachium

Question 1

Biceps brachii: O and I (for long and short heads)

Answer 1

Long head O: supraglenoid tubercle of scapula
Short head: coracoid process scapula
I: radial tuberosity, bicipital aponeurosis

Question 2

Biceps brachii A

Answer 2

Flex humerus, flex supine forearm, supinate forearm

Question 3

Innervation for anterior compartment of brachium

Answer 3

Musculocutaneous N

Question 4

Bicipital Myotactic Reflex

Answer 4

Sticking thumb placed over bicipital tendon with a reflex hammer -> tendon tightens and forearm flexes slightly

Question 5

If bicipital myotactic reflex fails, what two possible injuries?

Answer 5

Musculocutaneous N, C5-6 anterior rami damage

Question 6

Biceps tendinitis

Answer 6

Inflammation of long head of biceps tendon through intertubercular groove

Question 7

Popeye Deformity

Answer 7

Long head biceps brachii dislocates out of intertubercular groove -> muscle balls up in mid arm

Question 8

Coracobrachialis O and I

Answer 8

O: coracoid process
I: medial humerus

Question 9

Coracobrachialis A

Answer 9

Flex and adduct humerus

Question 10

Brachialis O and I

Answer 10

O: distal anterior humerus
I: ulnar tuberosity, coronoid process

Question 11

Brachialis A

Answer 11

Flex forearm

Question 12

Innervation posterior compartment of brachium

Answer 12

Radial N

Question 13

Triceps brachii origin of all three heads

Answer 13

Long: infraglenoid tubercle of scapula
Lateral: posterior humerus (superior to radial groove)
Medial: posterior humerus (inferior to radial groove)

Question 14

Triceps brachii I

Answer 14

Olecranon of ulna, antebrachial fascia

Question 15

Triceps brachii A

Answer 15

Extend forearm

Question 16

Anconeus O and I

Answer 16

O: lateral humeral epicondyle
I: lateral olecranon

Question 17

Anconeus A

Answer 17

Extends forearm, stabilizes elbow joint