Muscles Of The Upper Arm Flashcards
What are the 4 muscles of the upper arm?
Bicep brachii, coracobrachialis, brachialis and triceps brachii
What nerve innervates the Biceps?
Musculocutaneous
What nerve innervates the coracobrachialis?
Musculocutaneous
What nerve innervates the brachialis?
Musculocutaneous
With contributions from the radial nerve
What artery supplies the bicep brachii?
Branches of Brachial artery
What artery supplies the brachialis muscles?
Branches of brachial artery
and radial recurrent artery
What artery supplies the coracobrachialis muscle?
Brachial artery
What connective tissue sheet is given off as the biceps brachii enter the forearm?
Bicipital aponeurosis
What does the bicipital aponeurosis form?
The roof of the cubital fossa and blends with the deep fascia and anterior forearm
What are the attachments of the bicep brachii?
Long head- supraglenoid tubercle
Short head- coracoid process
Both heads insert distally into the radial tuberosity and fascia of the forearm via the bicipital aponeurosis
What is the function of the bicep brachii?
Supination of the forearm
Flexes the forearm
What does the bicep tendon reflex test?
Spinal cord segment C6
What are the attachments of the coracobrachialis?
Originates from the coracoid process of the scapula (passes through Axilla) attached to medial side of the humeral shaft (same level as deltoid tubercle)
What is the function of the coracobrachialis?
Flexion of the arm at the shoulder
Weak adduction
What are the attachments of the brachialis?
Originates from the medial and lateral surfaces of the humeral shaft and inserts into the ulna tuberosity (distal to the elbow joint)
What is the action of the brachialis?
Flexion at the elbow
Of the two heads which bicep tendon is more likely to rupture?
The long head
What are the characteristics of rupture of the bicep tendon?
Popeye sign (when elbow is flexed)
*wont notice much weakness in upper limb due to action of the brachialis and supination muscles
What is the muscle in the posterior compartment of the arm?
Tricep brachii
Which of the heads of the triceps lies deep?
The medial head
What is the arterial supply to the tricep brachii?
Profunda brachii artery
What are the 3 heads of the tricep called?
Lateral, long and medial
What are the attachments of the tricep brachii?
Long head -Originates from the infraglenoid tubercle
Lateral head- from the humerus, superior to radial groove
Medial head- humerus, inferior to radial groove
All heads converge and tendon inserts into the olecranon of the ulna
What is the function of tricep brachii?
Extension of the arm at the elbow
What is the innervation of the tricep brachii?
Radial nerve (C7, C8)
What does a tap on the tricep tendon test?
The spinal segment C7
