AN131: NAV

Question 1

What is the arterial supply of the upper limb?

Answer 1

1. axillary artery
2. brachial artery
3. ulnar artery
4. radial artery

Question 2

What are the veins of the upper limb?

Answer 2

superficial veins:
1. dorsal venous plexus
2. the cephalic vein
3. the basilic vein

these are superficial

Question 3

What veins are found deep and where are they found?

Answer 3

the deep veins essentially venae comitantes accompanying the arteries. These are:
1. venae comitantes of deep palmar arch (1) and superficial palmar arch (2)
3. venae comitantes of ulnar (1) and radial (2) arteries
4. venae comitantes of brachial artery

Question 4

Which vein connects the cephalic and basilic veins and what is unique about this?

Answer 4

The median cubital vein. It is the most prominent superficial vein in the human body and is used for intravenous injections or drawing blood.

Question 5

Where is the median cubital vein located?

Answer 5

Within superficial fascia of cubital fossa, one inch below elbow.

Question 6

Which vein is the axillary vein a continuation of?

Answer 6

The basilic vein, which is joined by the venae comitantes of the brachial artery.

Question 7

Is the axillary vein a superficial or deep vein and why?

Answer 7

Deep because it is the basilic vein after it pierces the deep fascia halfway through the arm.
- axillary vein ascends medially to the axillary artery (with other structures besides the lymph nodes separating them; lymph nodes are medial to axillary vein)

Question 8

What is the nerve supply of the upper limb?

Answer 8

The brachial plexus

Question 9

Where is the brachial plexus located?

Answer 9

It is formed in the posterior triangle of the neck by the union of the anterior rami of C5, C6, C7, C8, and T1 spinal nerves.

Question 10

nerves from roots

Answer 10

1. dorsal scapular nerve (C5)
2. long thoracic nerve (C5, C6, C7)

Question 11

nerves from upper trunk

C5 and C6

Answer 11

1. nerve to subclavius
2. suprascapular nerve

Question 12

non-terminal branching nerves of cords

Answer 12

1. lateral cord: lateral pectoral nerve [1]
2. posterior cord: upper and lower subscapular n., thoracodorsal nerve [3]
3. medial cord: medial pectoral nerve and medial cutaneous nerve of arm and medial cutaneous nerve of forearm [3]

Question 13

Terminal branches of the brachial plexus

Answer 13

1. lateral cord terminates as musculocutaneous nerve and lateral root of median n.
2. posterior cord terminates as radial nerve and axillary n.
3. medial cord terminates as ulnar nerve and medial root of median n.

Question 14

Which branch is the largest of the brachial plexus?

Answer 14

Radial nerve (lies behind axillary artery)

Question 15

What is clinically important about the nerve to the subclavius?

Answer 15

It may give a C5 contribution to the phrenic nerve, which would be a branch that is labelled as the accessory phrenic nerve.

Question 16

Motor supply of all nerves of the brachial plexus within the axilla

Answer 16

• nerve to subclavius: subclavius ms.
• long thoracic nerve: serratus anterior
• lateral pectoral nerve: pec. major
• musculocutaneous nerve: BBC (ant. comp. of arm, leaves axilla by piercing coracobrachialis ms.)
• medial pectoral n.: pec major and minor (pierces minor)
• medial cutaneous nerve of arm: supplies skin on medial side of arm
• upper subscapular nerve: subscapularis ms.
• lower subscapular nerve: subscapularis and teres major
• thoracodorsal n. : latissimus dorsi ms.

Question 17

Where are the cords of the brachial plexus?

Answer 17

in axilla, named after their position in relation to the second part of the axillary artery.

Question 18

In the first part of the axillary a., where are the cords located?

Answer 18

• medial cord is posterior to artery
• lateral and posterior cords are lateral to artery

NOTE: sheets say all cords are lateral to first part of axillary artery.

Question 19

What does the dorsal scapular nerve supply?

Answer 19

• rhomboids (major and minor)
• levator scapulae

Question 20

What injury may result in winging of the scapula?

Answer 20

Injury to long thoracic nerve, which will paralyze serratus anterior and result in winging of scapula.

Question 21

What does the suprascapular nerve supply?

Answer 21

has motor and articular branches:
- supraspinatus ms.
- infraspinatus ms.
- 2 joints: acriomioclavicular joint and shoulder joint

Question 22

Course of lateral pectoral nerve

Answer 22

Arises from lateral cord, pierces clavipectoral fascia, then pierces deep surface of pec major muscle to supply it.

Question 23

What is the medial cutaneous nerve of arm?

Answer 23

• smallest branch of brachial plexus (T1 only)
• from medial cord, it descends along the medial side of axillary v. to join the intercosto-brachial nerve (T2)
• supplies skin of lower third of medial side of arm; skin of armpit and upper medial side of arm are supplied by the intercosto-brachial nerve

Question 24

What are the types of each major branch from the brachial plexus?

Answer 24

1. median nerve: mixed
2. ulnar nerve: mixed
3. radial nerve: mixed
4. musculocutaneous nerve: mixed
5. axillary nerve: mixed

all are both sensory and motor

Question 25

Course of median nerve in arm and elbow

Answer 25

first, the medial root crosses in front of 3rd part of axillary a. to join lateral root 1. in the arm: lateral side of brachial a. in upper half, crosses in front of brachial a. at coracobrachialis insertion, and descends medially to brachial a. 2. at elbow: enters cubital fossa medial to brachial a., in front of brachialis muscle and behind bicipital **aponeurosis** 3. leaves cubital fossa btw. heads of pronator teres (ulnar head of pronator teres separates median n. from the deeper ulnar a.)

Question 26

Course of median n. in forearm and wrist:

Answer 26

1. in forearm: btw. FDP and FDS 2. at wrist: 5 cm. above wrist joint, median n. lies in interval btw. FCR (lat.) and PL (med). **Passes through carpal tunnel** 3. immediately forms medial and lateral terminal branches 4. forms pseudoganglion at lower ends after dividing into lateral and medial terminal branches.

Question 27

Course of ulnar nerve

Answer 27

1. in upper half of arm: medial to brachial artery 2. in middle of arm: pierces medial intermuscular septum (accompanied by superior ulner collateral a. and ulnar collateral nerve) to enter the posterior compartment of arm 3. lower half arm: in posterior compartment 4. at elbow: passes behind medial epicondyle of humerus (ulnar groove) 5. in forearm: descends medial to ulnar artery and in btw. the two heads of the FCU 6. at wrist: pierces deep fascia to lie superficially 7. in hand: passes above flexor retinaculum **outside carpal tunnel**, by the lateral border of pisiform bone in Guyon's canal. Superificially: skin and palmaris brevis m.

Question 28

Course of radial nerve | brief

Answer 28

1. in triangular interval: radial nerve and profunda brachii a. passes through 2. in upper half of arm: immediately enters posterior compartment of arm (btw. long and medial head of triceps). 3. middle and lower half of arm: descends into spiral groove and then pierces lateral intermuscular septum to enter ant. comp. (btw. brachialis and brachioradialis ms.) 10cm above lateral epicondyle.

Question 29

Course of musculocutaneous nerve

Answer 29

1. in arm: pierces coracobrachialis muscle and is lateral, in btw. biceps and brachialis ms. 2. continues as lateral cutaneous nerve of forearm (in superficial fascia)

Question 30

Course of axillary nerve

Answer 30

1. in axilla: infront of subscapularis and behind 3rd part of axillary artery, lateral to radial nerve 2. passes through quadrangular space (with posterior circumflex humoral vessels) 3. anterior and posterior divisions at surgical neck (beneath deltoid): posterior division supplies teres minor and continues as upper lateral cutaneous nerve of arm

Question 31

Sites of innervation by median nerve

Answer 31

- elbow and proximal radioulnar joints: articular - forearm: muscular to 4 muscles - in hand: muscular terminal branches

Question 32

Which muscles in forearm are innervated by median nerve?

Answer 32

1. pronator teres 2. flexor carpi radialis 3. palmaris longus 3. flexor digitorum superficialis

Question 33

Which is innervated by the anterior interosseous nerve?

Answer 33

1. muscular 2 1/2: flexor pollicis longus, half of FDP, and pronator quadratus 2. articular to: wrist and distal radioulnar joint

Question 34

Branching of median nerve in hand:

Answer 34

1. lateral terminal branch: 3 common palmar digital branches (sensory) & recurrent muscular branch (motor to thenar and 1st lumbrical) 2. medial terminal branch: 2 common palmar digital branches (sensory) & motor to 2nd lumbrical palmar cutaneous branch: 5cm prox. to wrist, passes **above** flexor retinac. to supply sensory for lateral 3 1/2 of fingers and distal half of the back of these fingers.

Question 35

Where is the recurrent muscular branch of the median nerve?

Answer 35

One fingerbreadth distal to tubercle of scaphoid

Question 36

Branching of ulnar nerve:

Answer 36

1. in forearm: motor (FCU and med. 1/2 of FDP) 2. in elbow: articular to elbow joint 3. branches into superficial and deep terminal branches as it crosses retinaculum

Question 37

Course of superficial branch of ulnar nerve

Answer 37

in subcutaneous tissue between pisisform bone and hook of hamate: osteofibrous tunnel of Guyon, with ulnar artery

Question 38

Nerve supply of superficial branch of ulnar nerve:

Answer 38

1. muscular: palmaris brevis 2. cutaneous to 5th and 1/2 of 4th fingers

Question 39

Cutaneous branches of ulnar nerve

Answer 39

1. palmar cutaneous branch: medial part of palm (mainly palm not over fingers much) 2. posterior cutaneous branch: medial third of dorsum of hand

Question 40

How does the dorsal cutaneous branch of ulnar nerve reach the dorsum of hand?

Answer 40

branches 5cm above wrist to descend over extensor retinaculum (like palmar, it does not pass through guyon's canal)

Question 41

Motor innervation of ulnar nerve

Answer 41

From deep branch of ulnar nerve: - hypothenar muscles - interossei ms: palmar and dorsal - lumbricals 3 and 4 - adductor pollicis (oblique and transverse head) - deep head of flexor pollicis ms

Question 42

Course of the deep branch of ulnar nerve

Answer 42

After Guyon's canal, deep branch will go between ADM and FDM, piercing opponens digiti minimi. Then it will wing around hook of hamate to pass laterally in deep palmar arch.