MSK 2.1 - The Anterior and Posterior Arm Flashcards
What is the origin of the short head of the biceps brachii?
Coracoid process of the scapula
Where does the biceps brachii insert?
The radial tuberosity
Describe the shape and size of the biceps brachii
- Large
- Two heads which combine to form a belly at the level of the humeral shaft
What is the nerve supply of the biceps brachii?
Musculocutaneous nerve (C5, C6)
Give the actions of the biceps brachii (4)
- Flexion of the elbow
- Supination of the forearm
- Flexion of the humerus at the shoulder
- Stabilisation of the shoulder joint (long head)
What happens if the tendon of the long head of the biceps brachii ruptures?
- Produces ‘Popeye sign’ upon flexion’
- Don’t notice any muscle weakness due to Brachialis and Supinator muscles
What is the origin of the Brachialis?
The medial and lateral surfaces of the humeral shaft
Where does the Brachialis insert? (2)
- Tuberosity of the ulna, distal to elbow joint
- Anterior surface of coronoid process of the ulna
Describe the size of the Brachialis
Small but bigger than the Coracobrachialis
What is the nerve supply of the Brachialis?
- Musculocutaneous nerve (C5 and C6)
- Radial nerve (C7)
Give the actions of the Brachialis (2)
- Flexion of the forearm
- Protection of the elbow
What is the origin of the Coracobrachialis?
Coracoid process of the scapula
Where does the Coracobrachialis insert?
Medial side of the humeral shaft
Describe the size of the Coracobrachialis
Small
What is the nerve supply of the Coracobrachialis?
Musculocutaneous nerve (C5-C7)
What are the actions of the Coracobrachialis?
- Flexion of the humerus
- Adduction of the humerus
What are the four borders of the cubital fossa?
- Medial and lateral epicondyles
- Medial border of the brachioradialis
- Lateral border of pronator Teres
- Median cubital vein
Give two clinically relevant features of the cubital fossa
- Feeling of brachial pulse medial to biceps tendon is relevant to taking blood pressure
- Medial cubital vein runs through which connects to basilic and cephalic veins both of which are common sites for venepuncture
Give the names of the three heads of the triceps brachii
- Lateral
- Medial
- Long
Where is the origin of the lateral head of the triceps brachii?
Between Teres minor and superior to groove of posterior surface of the humerus
Where is the origin of the medial head of the triceps brachii?
Inferior to the radial groove on the posterior shaft of the humerus
Where is the origin of the long head of the triceps brachii?
Infraglenoid tubercule of the scapula
Where do all three heads of the triceps brachii insert?
The olecranon of the ulna
What is the nerve supply of the triceps brachii?
The radial nerve (C7, C8)
