S7) The Upper Arm Flashcards
Where is the upper arm?
The upper arm is located between the shoulder joint and elbow joint
What are the muscles of the upper arm?
Identify the 3 muscles in the anterior compartment of the upper arm
- Biceps brachii
- Coracobrachialis
- Brachialis
Describe the neurovascular supply of the anterior compartment of the upper arm
- Innervated by the musculocutaneous nerve
- Arterial supply via muscular branches of the brachial artery
Describe the structure and function of the biceps brachii muscle
- Structure: two-headed muscle, bicipital aponeurosis forms the roof of the cubital fossa and blends with the deep fascia of anterior forearm
- Function: supination, elbow flexion, shoulder flexion
State the origin and attachment of the biceps brachii muscle
- Origin:
I. Long head – supraglenoid tubercle
II. Short head – coracoid process
- Attachment: radial tuberosity and the fascia of the forearm via the bicipital aponeurosis
Describe the structure and function of the coracobrachialis muscle
- Structure: lies deep to biceps brachii
- Function: shoulder flexion
State the origin and attachment of the coracobrachialis muscle
- Origin: coracoid process of the scapula
- Attachment: medial side of the humeral shaft, at the level of the deltoid tubercle
Describe the structure and function of the brachialis muscle
- Structure: lies deep to biceps brachii, found more distally than the other and forms the floor of the cubital fossa
- Function: elbow flexion
State the origin and attachment of the brachialis muscle
- Origin: medial and lateral surfaces of the humeral shaft
- Attachment: ulna tuberosity, distal to the elbow joint
Identify the muscle in the posterior compartment of the upper arm
Triceps brachii
Describe the neurovascular supply of the posterior compartment of the upper arm
- Innervated by the radial nerve
- Arterial supply via the profunda brachii artery
Describe the structure and function of the triceps brachii muscle
- Structure: three heads; medial head lies deeper than the other two
- Function: elbow extension
State the origin and attachment of the triceps brachii muscle
- Origin:
I. Long head – infraglenoid tubercle
II. Lateral head – above radial groove of humerus
III. Medial head – below radial groove of humerus
- Attachment: olecranon of the ulna
What is the cubital fossa?
The cubital fossa is triangular depression on the anterior surface of the elbow joint as the anatomical arm transitions to become the forearm
The cubital fossa is triangular in shape, and thus has three borders.
What are they?
Describe the structure of the floor and roof of the cubital fossa
- The floor is formed proximally by the brachialis, and distally by the supinator muscle
- The roof is formed of skin and fascia and is reinforced by the bicipital aponeurosis
Which structure runs in the roof of the cubital fossa?
Median cubital vein is located superficially within the roof of the cubital fossa and can be accessed for a venepuncture