Week 11 - Nerves of upper terminal nerves

Question 1

What is the origin of the musculocutaneous nerve?

Answer 1

Lateral cord (C5–C7)

Question 3

What is the innervation of the musculocutaneous nerve

Answer 3

Muscular branches: Muscles in the anterior compartment of the arm (biceps, brachii, brachialis, coracobrachialis)

Cutaneous branches: skin on lateral foramen

Question 4

What is the origin of the Axillary nerve

Answer 4

Posterior cord (C5-C6)

Question 5

What is the innervation of the Axillary nerve

Answer 5

Muscular branches: deltoid and terres minor

Cutaneous branches: gives rise to the upper lateral cutaneous nerve of arm, which innervates the skin over the lower deltoid

Question 6

what is the origin of the Radial nerve

Answer 6

Posterior cord (C5-C8, T1)

Question 7

What is the innervation of the Radial Nerve

Answer 7

Muscular Branches: Posterior muscles of arm and forearm (triceps brachii, brachioradialis, anconeus, supinaor, extnsor carpi radialis longus and brevis, extensor carpi ulnaris and muscles extending the fingers

Cutaneous branches: skin of posterolateral surface of the entire limb

Question 8

What is the origin of the median nerve

Answer 8

Origin: Form 2 branches

1. medal cord (C8-T1)
2. Lateral Cord (C5-C7)

Question 9

What muscles are innervated by the median nerve in the forearm?

Answer 9

the flexor muscles of the forearm and pronator muscles (except the flexor carpi ulnaris and part of the felxor digitorrum profundus, innervated by the ulnaris nerve

the median nerve enters the hand via the carpi tunnel to innervate intrinsic muscle sof lateral palm. Thenar muscles and later 2 lumbricles

Skin of the lateral two thirds of hand (palm side), dorsum of fingers 2&3

Question 10

What muscles are innervated by the median nerve in the forearm?

Answer 10

All flexors except flexor carpi ulnaris and medial half of flexor digitorum profundus (these are ulnar)

Question 11

What hand muscles are innervated by the median nerve?

Answer 11

Thenar muscles and lateral two lumbricals

Question 12

What cutaneous areas are supplied by the median nerve?

Answer 12

Palmar surface of the lateral 3½ fingers and corresponding palm; dorsal fingertips of the same fingers

Question 13

What is the origin of the ulnar nerve?

Answer 13

Medial cord (C8–T1)

Question 14

What muscles are innervated by the ulnar nerve?

Answer 14

Flexor carpi ulnaris

Medial half of flexor digitorum profundus

Hypothenar muscles

All interossei

Lumbricals 3 & 4

Question 15

What are the branches of the ulnar nerve that supply cutaneous sensation?

Answer 15

Palmar cutaneous branch – medial half of the palm

Dorsal cutaneous branch – medial 1½ fingers and dorsal hand

Superficial branch – palmar surface of medial 1½ fingers

Question 16

What are signs of long thoracic nerve injury?

Answer 16

Winging of scapula

Pain around neck, deltoid, scapula

Limited shoulder flexion and abduction

Question 17

What causes radial nerve injury in the arm and what are the symptoms?

Answer 17

Cause: Humeral fracture (radial groove)

Symptoms:

Wrist drop

Sensory loss over dorsum of hand

Question 18

What is carpal tunnel syndrome and what are the signs?

Answer 18

Compression of median nerve in the carpal tunnel

Signs:

Pain/tingling in median nerve distribution

Thenar muscle atrophy

Positive Tinel’s sign (tapping causes symptoms)

Question 19

LT: describe the course of the axillary nerve in respect to the shoulder joint and humerus?

Answer 19

Course: crossing the shoulder joint inferior, passing through the quadrangular space, wrapping around the posterior to surgical neck of humerus

Question 20

LT: describe the motor and sensory innervations of the axillary nerve?

Answer 20

Motor: deltiod and teres minor

Sensory: upper lateral side of the arm

Question 20

LT: describe the course of the radial nerve?

Answer 20

the radial nerve arises from the posterior surface of the humerus. it then passes through the cubital fossa and terminates in the posterior compartment of the forearm, by dividing into two terminal branches:

1. superficial (sensory)
2. Deep (motor)