Upper limb Neurology and Vascular Anatomy

Question 1

Where does the Axillary artery begin?

Answer 1

Begins at the lateral border of the 1st rib as a continuation of the subclavian artery and ends at the inferior border of teres major.

Question 2

The axillary artery is divided into 3 parts by what?

Answer 2

pectoralis minor

Question 3

What is the first part of the axillary artery?

Answer 3

Between lateral border of 1st rib and medial border of pectoralis minor

Branches:
Superior thoracic artery

Question 4

What is the second part of the axillary artery?

Answer 4

Posterior to pectoralis minor

Branches:
Thoracoacromial artery

Lateral thoracic artery

Question 5

What is the third part of the axillary artery?

Answer 5

From lateral border of pectoralis minor to the inferior border of teres major

Branches:
Subscapular artery

Anterior and posterior circumflex humeral arteries

Question 6

What is the Brachial Artery?

Answer 6

Continuation of the axillary artery

Begins at inferior border of teres major

Ends in the cubital fossa opposite the neck of the radius

Lies anterior to the triceps and brachialis and medial to the biceps brachii. At first it lies medial to the humerus and then anterior to it

Accompanies the median nerve as it passes inferolaterally, which crosses anterior to the artery

Question 7

What are the branches of the brachial artery?

Answer 7

Deep brachial artery

2. Nutrient humeral artery
3. Superior ulnar collateral artery
4. Inferior ulnar collateral artery

Divides into radial and ulnar arteries under the bicipital aponeurosis

Question 8

What are the boundaries of the cubital fossa?

Answer 8

Triangular area between pronator teres, brachioradialis, line between epicondyles

Question 9

What is the roof of the cubital fossa?

Answer 9

Deep fascia of the forearm, bicipital aponeurosis, median cubital vein, medial cutaneous nerve of forearm, lateral cutaneous nerve of forearm

Question 10

What is the floor of the cubital fossa?

Answer 10

Brachialis
Supinator

Question 11

What vein, artery and nerve is found in the cubital fossa?

Answer 11

Median cubital vein
Brachial artery
Median nerve

Question 12

What is the clinical significance of the cubital fossa?

Answer 12

Median cubital vein is often used for intravenous injections. Missed injections could be dangerous to underlying structure.

Question 13

What is the ulnar artery course and relations?

Answer 13

Cubital fossa

Deep to pronator teres, palmaris longus, and flexor digitorum superficialis

Medial side of the forearm, lateral to the ulnar nerve

Superficial to flexor retinaculum at wrist

Enters hand anterior to flexor retinaculum between pisiform and hook of hamate

Superficial and deep palmar arches

Question 14

What is the radial artery course and relations?

Answer 14

Cubital fossa

Passes inferolaterally under brachioradialis

Distally lies lateral to flexor carpi radialis tendon

Winds around lateral aspect of radius

Curves dorsally around scaphoid and trapezium in floor of anatomical snuff box to pierce fascia

Enters palm between heads of 1st dorsal interosseous muscle

Turns medially and passes between heads of adductor pollicis

Deep and superficial palmar arches

Question 15

What is the brachial plexus?

Answer 15

A major network supplying the upper limb formed by the union of ventral rami of C5 to C8 nerves and the most of the ventral ramus of T1

Begins in neck and extends to the axilla

Almost all branches arise in the axilla

Question 16

The brachial plexus is made up of 5 sections. What are they?

Answer 16

Roots, Trunks, Divisions, cords and terminal branches (peripheral nerves)
They are C5 C6 C7 C8 T1

Question 17

How are brachial plexus injuries usually caused?

Answer 17

trauma to the roots of the plexus as they exit the cervical spine.
This most commonly occurs in road traffic accidents and falls from height. Inflammatory, neoplastic, and compressive causes are also possible.
The effects of the injury include paralysis, loss of sensation, and pain.
The specific clinical presentation will depend on the roots involved and the degree of injury to each root.

Question 18

What is an avulsion in regards to brachial plexus injury?

Answer 18

In this most severe brachial plexus injury, the nerve root has been torn from the spinal cord. These types of injuries may not be repairable with surgery

Question 19

What is a stretch (neuropraxia) in regards to brachial plexus injury?

Answer 19

When the nerve is mildly stretched, it may heal on its own or require simple, nonsurgical treatment methods to return to normal function.

Question 20

What is a rupture in regards to a brachial plexus injury?

Answer 20

A more forceful stretch of the nerve may cause it to tear partially or fully. These types of injuries can sometimes be repaired with surgery.

Question 21

What is an upper-trunk palsy injury?

Answer 21

When a fall forces the shoulder down and the head to the opposite side,
upper-trunk palsy can result.

Question 22

What is a lower-trunk palsy injury?

Answer 22

Lower brachial plexus injuries occur when the arm and shoulder are forced upward,
increasing the angle between the arm and the chest.

Question 23

What and where is the musculocutaneous nerve?

Answer 23

From lateral cord (C5-C7)

Begins at the inferior border of pectoralis minor,
Pierces coracobrachialis and continues distally between biceps brachii and brachialis

Becomes the lateral cutaneous nerve of the forearm, which travels down the lateral forearm to the wrist, supplying the skin of the lateral forearm

Supplies all muscles in the anterior (flexor) compartment of the arm
Innervates coracobrachialis, biceps brachii and brachialis

Question 24

What and where is the median nerve?

Answer 24

Formed in axilla by union of lateral (C6/C7) and medial cords (C8/T1)

Lateral to axillary artery
Lateral to brachial artery to middle arm,
then crosses to the medial side
and contacts the brachialis muscle
Enters cubital fossa medial to brachial artery, deep to the bicipital aponeurosis and median cubital vein

Passes between heads of pronator teres
Descends between flexor digitorum superficialis and flexor digitorum profundus
Enters the hand through the carpal tunnel deep to flexor retinaculum along with tendons of flexor digitorum superficialis and profundus, and flexor pollicis longus

Question 25

What does the median nerve supply in the forearm?

Answer 25

Flexor muscles (except flexor carpi ulnaris & ulnar half of flexor digitorum profundus)

Question 26

Distal to the carpal tunnel, the median nerve supplies what?

Answer 26

3 thenar muscles and 1st and 2nd lumbricals

Question 27

The median nerve gives sensation to?

Answer 27

Palm and palmar surface of 1st three digits,
the lateral half of the 4th digit,
the dorsum of the distal halves of these digits

Palmar cutaneous branch supplying the central palm (*), arises proximal to the carpal tunnel runs superficial to the flexor retinaculum, and is therefore not affected in carpal tunnel syndrome

Question 28

What are the branches of the median nerve?

Answer 28

Has no branches in the upper arm

Articular branches to the elbow

Anterior interosseous nerve
Median nerve just distal to cubital fossa
Passes inferiorly on interosseous membrane
Supplies flexor digitorum profundus, flexor pollicis longus, and pronator teres

Palmar cutaneous branch of median
Median nerve just proximal to flexor retinaculum
Passes between palmaris longus and flexor carpi radialis tendons
Runs superficial to flexor retinaculum

Question 29

What and where is the ulnar nerve?

Answer 29

Known as the nerve of fine movements as it innervates muscles concerned with fine hand movements
From medial cord (C8/T1 often C7)

Anterior to triceps
Medial to brachial artery
Mid arm it pierces the medial intermuscular septum with the superior ulnar collateral artery
Descends between the septum and medial head of triceps
Descends along medial arm to run posterior to the medial epicondyle (where it is superficial and vulnerable to injury) and medial to the olecranon
Enters forearm between heads of flexor carpi ulnaris
Descends between flexor carpi ulnaris and flexor digitorum profundus to become superficial in distal forearm
Passes superficial to flexor retinaculum
Emerges deep to tendon of flexor carpi ulnaris, and is bound in the fascia of the wrist in the anterior surface of the flexor retinaculum
Passes along lateral border of the pisiform, medial to the ulnar artery
Ends at distal border of flexor retinaculum by dividing into superficial and deep branches

Innervates one and a half flexor muscles in the forearm, most small muscles in the hand, and skin of the hand medial to a line bissecting 4th digit

Question 30

What are the branches of the ulnar nerve?

Answer 30

Has no branches in the arm
Articular branches to the elbow

Palmar cutaneous branch of ulnar nerve
Descends on ulnar artery and perforates deep fascia in distal third of forearm
Supplies the skin on the medial side of the palm

Dorsal cutaneous branch
Supplies the medial half of the dorsum of the hand,
the 5th digit, and the medial half of the 4th digit

Superficial branch
Supplies cutaneous branches to anterior surfaces of the medial one and a half digits

Deep branch
Supplies the hypothenar muscles, the medial two lumbricals,
the adductor pollicis, and all the interossei
Also supplies several joints (wrist, intercarpal, carpometacarpal, and intermetacarpal)

Question 31

What and where is the radial nerve?

Answer 31

From posterior cord (C5-T1)

Posterior to axillary artery
Enters radial groove with deep brachial artery
Enters arm posterior to brachial artery and medial to the humerus
Between the long and medial heads of triceps, running anterior to long head of triceps
Descend inferolaterally with brachial artery to pass around humeral body in the radial groove
Gives branches to the long and lateral heads of triceps before entering groove
Branch to medial head arises in the groove
Pierces the lateral intermuscular septum at the lateral border of the humerus
Continues inferiorly in the anterior compartment of the arm between brachialis and brachioradialis into the cubital fossa
And divides into superficial and deep branches at the level of the lateral epicondyle

Question 32

Where is the superficial branch of the radial nerve?

Answer 32

Arises in cubital fossa
Direct continuation of the radial nerve after deep branch is given off
Passes distally along the anterolateral side of the forearm, anterior to pronator teres and deep to brachioradialis
Pierces deep fascia near the dorsum of the wrist
And passes onto dorsum of hand
Entirely sensory, and supplies the skin and fascia over the lateral two thirds of the dorsum of the hand, the dorsum of the thumb, and the proximal parts of the lateral one and a half digits

Question 33

Where is the deep branch of the radial nerve?

Answer 33

Arises in the cubital fossa from the radial nerve distal to the elbow
It winds around neck of radius in supinator and enters posterior compartment

Question 34

The radial nerve supplies all muscles in the posterior (extensor) compartment. True or False?

Answer 34

True

Question 35

The radial nerve innervates what muscles?

Answer 35

triceps brachii, anconeus, brachioradialis, and extensor muscles of forearm

Question 36

Does the radial nerve supply nerves of the arm and hand?

Answer 36

Supplies skin on posterior aspect of arm and forearm via posterior cutaneous nerves of arm and forearm
Superficial branch is entirely cutaneous, supplying sensation to the dorsum of the hand and digits
Deep branch has an entirely muscular and articular distribution

Question 37

What are the branches of the Radial Nerve?

Answer 37

Supplies no hand muscles

Posterior brachial cutaneous nerve
Supplies skin on posterior surface of the arm

Posterior antebrachial cutaneous nerve
Supplies skin of posterior surface of forearm

Inferior lateral cutaneous nerve of the arm
Supplies skin over the inferolateral aspect of the arm

Posterior interosseous
Terminal branch of deep branch of radial nerve
Passes deep to extensor pollicis longus and ends on interosseous membrane

Question 38

What and where is the Axillary nerve?

Answer 38

From posterior cord (C5 and C6)

Passes to posterior aspect of arm through the quadrangular space* in company with posterior circumflex humeral artery
Curls around surgical neck of humerus

Innervates teres minor and deltoid, glenohumeral joint, and skin over inferior part of deltoid

(*) Quadrangular space is bounded superiorly by subscapularis and teres minor, inferiorly by teres major, medially by long head of triceps and laterally by humerus

Question 39

What are the axillary nerve’s branches?

Answer 39

Superior lateral brachial cutaneous nerve
Supplies skin over the lower part of the deltoid and lateral side of the mid arm

Question 40

What are other nerves of the brachial plexus with supraclavicular branches?

Answer 40

Dorsal scapular
Long Thoracic (C5-C7)
Nerve to subclavius (C5/C6)
Suprascapular nerve

Question 41

What are other nerves of the brachial plexus with infraclavicular branches?

Answer 41

Medial Pectoral (C8/T1)and
Lateral Pectoral (C5-C7)
Medial Brachial Cutaneous (C8/T1)
Medial Antebrachial Cutaneous (C8/T1)
Thoracodorsal (C6-C8)
Upper and Lower Subscapular (C5/C6)