Posterior Compartment of the Arm Flashcards
What does the triceps occupy?
Occupies the entire posterior compartment of the arm.
It arises by a long head from the scapula and by two shorter heads - the lateral and medial heads - from the humerus.
The common tendon of triceps is inserted into what?
Olecranon process of the ulna
Which head of the triceps attaches onto the infra-glenoid tubercle of the scapula?
Long head
What is the main action of triceps on the elbow joint?
Extensor
What is the action of the triceps and anconeus muscle?
Extension of the elbow
What is the nerve supply to triceps and anconeus?
Radial nerve
What is the radial nerve a branch of?
Enters the arm anterior to the lateral epicondyle head of triceps and runs with the profunda brachii artery (deep artery of the arm), a main branch of the brachial artery.
What does the radial nerve innervate?
C5-T1
The radial nerve enters the arm anterior to what?
Anterior to the lateral epicondyle head of triceps and runs with the profunda brachii artery (deep artery of the arm), a main branch of the brachial artery.
Where does the radial nerve descend down?
It descends down the around the midshaft region of the humerus in the radial groove, then appears as one of the most lateral structures of the distal arm lying between the humerus and the long and medial head of the triceps muscles.
What is the segmental (root value) value of the radial nerve?
C5-T1
What is the characteristic clinical sign of radial nerve injury?
Numbness from triceps to fingers, problems extending wrist or fingers, pinching and grasping problems, weakness or inability to control muscles and wrist drop
