Anatomy of the Arm: Muscles, Nerves, and Cubital Fossa

The Arm

,• The arm extends from the shoulder joint till
the elbow joint.
• The skeleton of the arm is a 'solo' bone, the
humerus.

COMPARTMENTS OF THE ARM
• The arm is divided into:
✓Anterior compartment
✓Posterior compartment

, Anterior Compartment

• Muscles of the anterior
compartment of the arm are:
1. Coracobrachialis
2. Biceps brachii
3. Brachialis

, Muscle Name Origin Insertion Nerve Function
Supply
Tip of the coracoid The middle 5 cm of Musculo- Flexes the arm at the
Coraco- process the medial border of cutaneous nerve shoulder joint
brachialis the humerus (C5-C7)


It has two heads Posterior rough Musculo- • It is strong supinator
Biceps cutaneous nerve when the forearm is
1. Short head- tip of part of the radial
Brachii the coracoid tuberosity of
(C5-C7) flexed.
• Flexion of elbow.
process. Radius • The short head is a
2. Long head- flexor of the arm.
supraglenoid • The long head prevents
tubercle of the upwards displacement of
the head of the humerus
scapula

Distal half of the Anterior surface of Musculo- Flexes forearm at the
Brachialis Coronoid process and cutaneous nerve elbow joint
front of the humerus
ulnar tuberosity (C5-C7)