Anterior compartment of the arm and musculocutaneous nerve Flashcards
What do fasical compartments contain?
Fascial compartments contain groups of muscles and neurovascular structures enveloped by a layer of connective (fibrous) tissue. Muscles in each compartment often (but not always) act similarly on a joint, sharing a common nerve and blood supply
What does the anterior compartment of the arm contain?
The anterior compartment contains 3 important muscles and their accompanying neurovascular supply.
The muscles act on the elbow joint and superior radio-ulnar joint,
Explain the leve of the biceps brachii and the heads of it
The biceps brachii is the most superficial muscle of the anterior compartment.
It arises from the scapula via two heads.
Both heads unite at the distal third of the upper arm forming a short tendon which inserts onto the radial tuberosity.
What does the biceps brachii attach through the bicipital aponeurosis to?
The deep fascia of the forearm
The muscle has a powerful action on the shoulder, elbow and radio-ulnar joints.
What do the short heads of the biceps muscle originate from?
Biceps muscle originates from the coracoid process of the scapula.
Where does the long head of the biceps muscle originate?
The long head of the biceps muscle originates from the supraglenoid tubercle of the scapula.
Its tendon passes through the shoulder joint and runs down the biciptal groove of the humerus.
What are the action of the biceps brachii?
Both the shoulder and elbow joint
At the superior radio-ulnar joint it is involved in supination (the action in which the radius rotates over the ulna)
What is the coracobrachialis muscle?
Slender, rounded muscle passing from its origin at the tip of the coracoid process and inserting to the medial aspect of the mid-shaft of the humerus
What is the action of the coracobrachialis?
Its action is to flexes the arm at the shoulder joint
What does the brachialis muscle arise from?
Arises from the anterior surface of the distal shaft of the humerus. It is a deep muscle of the anterior compartment, passing downwards and attaching to the Coronoid process of the Ulna
What is the main action of the brachialis muscle?
Flex the elbow joint
What does the musculocutaneous nerve arise from?
Arises as a terminal branch from the lateral cord of the brachial plexus.
