Radial Nerve Anatomy and Function

Questions and Answers

What is the primary origin of the radial nerve?

Lateral cord of the brachial plexus

Posterior cord of the brachial plexus (correct)

Roots of C4 and C5

Medial cord of the brachial plexus

In which anatomical location does the radial nerve split into its superficial and deep branches?

At the shoulder joint

Within the radial groove of the humerus

At the level of the medial epicondyle

In the cubital fossa (correct)

Which nerves contributes to the lateral surface innervation of the arm?

Superior lateral cutaneous nerve and inferior lateral cutaneous nerve (correct)

Deep branch of radial nerve and axillary nerve

Medial cutaneous nerve and intercostobrachial nerve

Posterior cutaneous nerve and medial cutaneous nerve

Which structure accompanies the radial nerve in the radial groove of the humerus?

Deep artery of arm Signup and view all the answers

What nerves branch off from the radial nerve during its course?

Posterior antebrachial cutaneous nerve and inferior lateral brachial nerve Signup and view all the answers

What is the area of skin innervated by the posterior cutaneous nerve of arm?

Posterior surface of the arm Signup and view all the answers

Which of the following nerve fibers are included in the radial nerve?

C5, C6, C7, C8 and T1 nerve fibers Signup and view all the answers

Which of the following statements correctly describes the course of the radial nerve?

It passes posteriorly through the radial groove of the humerus. Signup and view all the answers

What nerves provide innervation to the lateral surface of the arm?

Inferior lateral cutaneous nerve of arm and superior lateral cutaneous nerve of arm Signup and view all the answers

Which branch of the radial nerve arises in the cubital fossa?

Deep branch Signup and view all the answers

The radial nerve is the largest branch of which anatomical structure?

Brachial plexus Signup and view all the answers

Which of the following techniques would likely be least effective for accessing the radial nerve?

Passing through the medial intermuscular septum Signup and view all the answers

Which of the following nerves is NOT a branch of the radial nerve?

Medial cutaneous nerve of arm Signup and view all the answers

At which point does the radial nerve pass into the cubital fossa?

Between brachialis and brachioradialis Signup and view all the answers

Study Notes

Radial Nerve Overview

Originates from the posterior cord of the brachial plexus.
Comprises fibers from C5, C6, C7, C8, and T1, making it the largest branch of the brachial plexus.

Course of the Radial Nerve

Travels from the axilla to the posterior compartment of the arm.
Located between the heads of the triceps brachii within the radial groove of the humerus.
Accompanied by the deep artery of the arm.
Gives rise to the posterior antebrachial cutaneous nerve and the inferior lateral brachial nerve.
Pierces the lateral intermuscular septum of the arm.
Enters the cubital fossa between the brachialis and brachioradialis muscles.

Division in the Cubital Fossa

At the lateral epicondyle of the humerus, the radial nerve divides into:
- Superficial branch
- Deep branch

Skin Innervation of the Arm

Medial Surface:
- Innervated by the medial cutaneous nerve of the arm (from medial cord of the brachial plexus).
- Intercostobrachial nerves (from the 2nd intercostal nerve) supply the axillary skin.
Lateral Surface:
- Superior lateral cutaneous nerve of the arm (from axillary nerve).
- Inferior lateral cutaneous nerve of the arm (from radial nerve).
Posterior Surface:
- Posterior cutaneous nerve of the arm (from radial nerve).

Radial Nerve Overview

Originates from the posterior cord of the brachial plexus.
Comprises fibers from C5, C6, C7, C8, and T1, making it the largest branch of the brachial plexus.

Course of the Radial Nerve

Travels from the axilla to the posterior compartment of the arm.
Located between the heads of the triceps brachii within the radial groove of the humerus.
Accompanied by the deep artery of the arm.
Gives rise to the posterior antebrachial cutaneous nerve and the inferior lateral brachial nerve.
Pierces the lateral intermuscular septum of the arm.
Enters the cubital fossa between the brachialis and brachioradialis muscles.

Division in the Cubital Fossa

At the lateral epicondyle of the humerus, the radial nerve divides into:
- Superficial branch
- Deep branch

Skin Innervation of the Arm

Medial Surface:
- Innervated by the medial cutaneous nerve of the arm (from medial cord of the brachial plexus).
- Intercostobrachial nerves (from the 2nd intercostal nerve) supply the axillary skin.
Lateral Surface:
- Superior lateral cutaneous nerve of the arm (from axillary nerve).
- Inferior lateral cutaneous nerve of the arm (from radial nerve).
Posterior Surface:
- Posterior cutaneous nerve of the arm (from radial nerve).

Description

Test your knowledge on the anatomy of the radial nerve, its origin from the brachial plexus, and its course through the arm. This quiz covers key facts about the nerve's branches and relevant anatomical landmarks. Perfect for students studying human anatomy or medical sciences.