Anatomy Ch. 51: Summarized Neurovascular Structures of the Upper Limb

Deep branch of the radial nerve

The deep branch of the radial nerve innervates the extensor carpi radialis brevis. As the nerve enters the superior border of the supinator muscle, its name changes to the posterior interosseous nerve (PIN)

Once the median nerve courses thru the carpal canal and enters the canal, what happens to it?

The median nerve then divides into its terminal branches at the distal border of the flexor retinaculum.

Palmar branch of ulnar nerve vs median nerve

*BOTH* branches are given off proximal to the flexor retinaculum, course anterior to the flexor retinaculum, and cutaneously innervates the skin of the palm. *Median palmar branch* innervates the LATERAL palm skin. *Ulnar palmar branch* innervates the skin of the MEDIAL palm.

Digital branches of the median nerve give ________ innervation to the (medial/lateral) (#) digits anteriorly and their tips posteriorly.

*cutaneous* innervation *lateral 3.5* digits

As the median nerve travels thru the cubital fossa, it lies (medial/lateral) to the (artery name).

*medial* to the *brachial* artery.

Direct branches of the median nerve provide ___________ innervation to lumbricals # and #.

*muscular* innervation to lumbricals *1* and *2*.

Palmar branch of median nerve

-given off proximal to the flexor retinaculum -courses anterior to the flexor retinaculum to cutaneously innervate the skin of the lateral palm.

The aortic arch gives off which 3 named branches

1. brachiocephalic trunk (which bifurcates into the right common carotid and right subclavian arteries) 2. Left common carotid 3. left subclavian

The radial nerve innervates which 3 muscles of the forearm? (not arm)

1. brachioradialis 2. extensor carpi radialis longus 3. anconeus

Which 3 arm muscles are innervated by the musculocutaneous nerve?

1. coracobrachialis 2. biceps brachii 3. brachialis.

Which 8 muscles does the posterior interosseous nerve (PIN) innervate in the forearm?

1. extensor digitorum 2.extensor digiti minimi 3. extensor carpi ulnaris 4. extensor pollicis brevis 5. extensor pollicis longus 6. extensor indicis 7. supinator 8. abductor pollicis longus

6 named branches of the axillary artery

1. highest (supreme) thoracic artery 2. thoracoacromial trunk 3. lateral thoracic artery 4. subscapular artery 5. anterior circumflex humeral artery 6. posterior circumflex humeral artery

3 named branches of brachial artery in the arm. What do they supply?

1. profunda brachii artery (posterior to humerus courses with the radial nerve) 2. superior ulnar collateral artery 3. inferior ulnar collateral artery supply muscles in the arm and provide collateral circulation to the elbow region.

Between which two muscles does the radial nerve divide into two terminal branches? (Deep, superficial branches)

Between the brachialis and brachioradialis muscles.

In the distal forearm, the ulnar nerve gives off a (ventral/dorsal) branch

In the distal forearm, the ulnar nerve gives off a *dorsal* branch

Where does the ulnar nerve divide into its 2 terminal branches? what are the 2 terminal branches?

Lateral to the pisiform bone 1. superficial branch 2. deep branch

PIN arises from ____ whereas AIN arises from _____

PIN is the deep branch of the radial nerve once it enters the superior border of the supinator muscle. AIN is a branch of the median nerve, given off within the cubital fossa.

The common interosseous artery

arises from the ulnar artery in the proximal forearm courses a short distance then divides into 2 terminal branches in the forearm: anterior and posterior interosseous arteries.

Where does the axillary artery terminate?

at the inferior border of the teres major by continuing as the brachial artery.

How does the subclavian artery terminate?

at the lateral border of the 1st rib it terminates by becoming the axillary artery.

How does the ulnar artery terminate?

by forming the superficial palmar arch, which is usually compelted by a branch of the radial artery.

In the proximal forearm, the ulnar artery gives off which artery?

common interosseous artery

The recurrent branch of the median nerve courses (distally/proximally) into the thenar area supplying (#) thenar muscles.

courses *proximally* into the thenar area supplying *2.5* thenar muscles.

Deep branch of the ulnar nerve.

courses between 2 hypothenar muscles. courses around the hook of hamate to pass laterally across the palm, just anterior to the interossei muscles. Innervates 14.5 muscles of the hand.

Superficial branch of the ulnar nerve.

courses deep to the palmaris brevis muscle. innervates the palmaris brevis only Divides into cutaneous digital branches that supply the medial 1.5 digits anteriorly.

Superficial branch of the radial nerve

courses distally with the radial artery deep to the brachioradialis muscle. In the wrist, the nerve passes over the tendons of the anatomical snuffbox and enters the hand to provide cutaneous innervation to the skin on the lateral half of the dorsum of the hand, and the proximal portion of the lateral 3.5 digits, posteriorly. *HAS NO MUSCULAR INNERVATION*

After the ulnar nerve passes from the medial to posterior compartment of the arm, what does it do?

courses posterior to the medial epicondyle.

How does the radial artery course in the forearm?

courses with the superficial branch of the radial nerve deep to the brachioradialis passes thru anatomical snuffbox, enters the dorsum of the hand.

The dorsal branch of the ulnar nerve *cutaneously* innervates what?

cutaneously innervates the dorsum of the medial 1.5 digits + hand.

After giving off the common interosseous artery, how does the ulnar artery course and with what nerve?

deep to the arch of the flexor digitorum superficialis with the *median* nerve.

anatomical snuffbox

depression located proximal to the thumb on the posterolateral side of the hand.

The aortic arch terminates as ____________, which courses inferiorly through the thorax and abdomen.

descending aorta

The musculocutaneous nerve descends through the (posterior/anterior/medial) compartment of the arm, coursing between (muscle #1) and (muscle #2)

descends through the *anterior* compartment courses between the *biceps brachii* and *brachialis* muscles.

The ulnar nerve innervates which 1.5 muscles of the forearm?

flexor carpi ulnaris medial 1/2 of the flexor digitorum profundus.

In the proximal forearm, the median nerve passes deep to the arch of the (muscle) with the (artery).

flexor digitorum superficialis ulnar artery

The median nerve descends through the forearm between which two muscles?

flexor digitorum superficialis and the flexor digitorum profundus.

The aorta initially ascends then arches (posteriorly/anteriorly/inferiorly) and towards the (right/left) to form the aortic arch.

initially ascends and then arches *posteriorly* toward the *Left* to form the aortic arch.

After the musculocutaneous nerve emerges lateral to the biceps brachii tendon, what does it become? what does it do?

it becomes the *lateral antebrachial cutaneous nerve (LAC)*. The LAC supplies the skin of the lateral forearm.

The radial nerve passes through the (medial/lateral) side of the cubital fossa.

lateral

The anterior interosseous nerve innervates which 4 muscles in the forearm?

lateral 1/2 of flexor digitorum profundus flexor pollicis longus pronator quadratus

the lateral and medial roots of the median nerve arise from which cords of the brachial plexus?

lateral and medial cords.

Positioning of brachial artery in the cubital fossa

lateral to median nerve medial to tendon of biceps brachii

The axillary artery courses (medially/laterally) and (superiorly/inferiorly) through the axilla.

laterally and inferiorly

The median nerve descends through the (anterior/posterior/medial) compartment of the arm.

medial

The brachial artery descends through WHICH compartment of the arm with which WHICH 2 nerves?

medial compartment with the median and ulnar nerves.

As the (primary nerve) enters the forearm, it courses between the two heads of origin of the pronator teres muscle.

median nerve

Primary nerve that originates from the lateral and medial roots of the median nerve.

median nerve

The anterior interosseous nerve arises as a branch of the (primary nerve) within the cubital fossa.

median nerve

The superficial palmar arch gives off which arteries?

metacarpal arteries (as does the deep palmar arch)

The deep palmar arch gives off which arteries? What do they from?

metacarpal arteries, which then join the metacarpal arteries of the superficial palmar arch to form the digital arteries on the medial and lateral side of each digit.

What are the four primary nerves of the upper limb?

musculocutaneous median ulnar radial

Primary nerve that is a continuation of the LATERAL cord (only) of the brachial plexus

musculocutaneous nerve begins AFTER the lateral root of the median nerve is given off

Does PIN ever enter the hand?

no

Proximal to the flexor retinaculum, the ulnar nerve gives off which branch?

palmar branch.

Describe how the ulnar nerve enters the hand.

passes anterior to the flexor retinaculum, outside the carpal canal, and through Guyon's canal.

The median nerve innervates which 4 muscles of the forearm?

pronator teres flexor carpi radialis palmaris longus flexor digitorum superficialis

Where does the median nerve give off the palmar branch?

proximal to the flexor retinaculum.

Which primary nerve pierces the lateral intermuscular septum as it passes from the posterior to anterior compartment of the arm?

radial nerve

Which primary nerve courses from medial to lateral in the radial groove of the humerus? Which compartment of the arm is this?

radial nerve, posterior compartment.

Which primary nerve is the continuation of the posterior cord of the brachial plexus, beginning after the axillary nerve is given off?

radial nerve.

Subclavian artery

right comes from brachiocephalic trunk, left comes from the aortic arch directly. ascends thru the thorax and neck toward the upper limb gives off branches becomes the axillary artery at lateral border of 1st rib

How does the radial artery terminate?

terminates by forming the deep palmar arch, which is completed by a branch of the ulnar artery.

What nerve courses distally along the anterior surface of the interosseous membrane?

the anterior interosseous nerve (AIN)

Within the cubital fossa, the median nerve gives off a branch called ______________?

the anterior interosseous nerve (AIN)

What muscle does the musculocutaneous nerve pierce?

the coracobrachialis

The ulnar nerve courses with the ulnar artery where?

the distal half of the forearm.

The ulnar nerve courses through the forearm between which two muscles?

the flexor carpi ulnaris and flexor digitorum profundus muscle.

The common carotid arteries supply what?

the head and neck

What innervates the skin of the lateral palm?

the palmar branch of the median nerve.

Which artery does the radial nerve course with?

the profunda brachii artery.

Which arm muscle does the radial nerve innervate (not forearm)?

triceps brachii

Which 2 primary nerves descend through the medial compartment of the arm, where they have no muscular or cutaneous innervation.

ulnar and median nerves.

In the distal 1/2 of the forearm, the ulnar artery courses with *which nerve* between the flexor carpi ulnaris and digitorum profundus muscles?

ulnar nerve

The (primary nerve) enters the forearm by passing between the 2 heads of origin of the flexor carpi ulnaris muscle.

ulnar nerve

What nerve pierces the posterior lamina of the medial intermuscular septum, passing from the medial to posterior compartment of the arm?

ulnar nerve

Which primary nerve is the continuation of the medial cord of the brachial plexus AFTER the medial root of the median nerve is given off?

ulnar nerve

The majority of the branches off of the subclavian arteries supply what?

upper limbs

branches of the subclavian

vertebral internal mammary (AKA internal thoracic) thyrocervical trunk costocervical trunk

How/where does the brachial artery terminate?

within the cubital fossa, divides into 2 terminal branches: 1. radial artery 2. ulnar artery

Is the ulnar nerve accompanied by the ulnar artery in the wrist?

yes