Upper Arm Muscles and Innervation

This tutorial covers the muscles of the upper arm, divided into anterior and posterior compartments. The anterior compartment, known as the flexor compartment, includes the biceps brachii, coracobrachialis, and brachialis muscles, all innervated by the musculocutaneous nerve. The posterior compartment, or extensor compartment, contains the triceps brachii, innervated by the radial nerve. The tutorial also explains the intermuscular septum and deep fascia, which separate these compartments, and discusses compartment syndrome, a condition requiring emergency treatment to prevent neurovascular damage.

What separates the anterior and posterior compartments of the upper arm?

• The bicipital aponeurosis

• The radial nerve

• The deltoid muscle

• The humerus and intermuscular septum

Which nerve innervates the muscles of the anterior compartment of the upper arm?

• Radial nerve

• Musculocutaneous nerve

• Ulnar nerve

• Median nerve

What is the primary function of the biceps brachii muscle?

• Extends the forearm

• Rotates the shoulder

• Flexes and supinates the forearm

• Adducts the arm

Where does the long head of the biceps brachii originate?

• Coracoid process

• Infraglenoid tubercle

• Radial tuberosity

• Supraglenoid tubercle

What is the function of the coracobrachialis muscle?

• Supinates the forearm

• Flexes the arm at the shoulder joint

• Extends the elbow

• Flexes the forearm

Where does the brachialis muscle insert?

• Ulnar tuberosity

• Coracoid process

• Olecranon process

• Radial tuberosity

How many heads does the triceps brachii muscle have?

• One

• Two

• Three

• Four

What is the primary action of the triceps brachii muscle?

• Flexes the elbow

• Extends the elbow

• Supinates the forearm

• Adducts the arm

Which nerve innervates the muscles of the posterior compartment of the upper arm?

• Musculocutaneous nerve

• Ulnar nerve

• Radial nerve

• Median nerve

Where does the long head of the triceps brachii originate?

• Radial tuberosity

• Supraglenoid tubercle

• Coracoid process

• Infraglenoid tubercle