Axilla, brachial plexus and breast

Question 1

What forms the floor of the axilla?

Answer 1

Deep fascia, subcutaneous tissue and skin

Question 2

What forms the anterior wall of the axilla?

Answer 2

Pectoralis major and minor

Subclavius

Clavipectoral fascia

Question 3

What forms the posterior wall of the axilla?

Answer 3

Subscapularis

Teres major

The tendon of latissimus dorsi winding around teres major

Question 4

Which extends lower, the anterior or posterior border of the axilla?

Answer 4

Posterior

Question 5

What forms the medial wall of the axilla?

Answer 5

Serratus anterior

Question 6

What forms the lateral wall of the axilla?

Answer 6

Intertubercular or bicipital groove of the humerus

Question 7

The axillary artery is a continuation of which other vessel?

Answer 7

Subclavian artery

Question 8

Where does the axillary artery begin?

Answer 8

The outer border of the first rib

Question 9

What are the branches of the axillary artery?

Answer 9

Subscapular

Anterior and posterior circumflex humeral arteries

Branches to the pectoral muscles, breast and chest wall

Question 10

What does the subscapular artery become?

Answer 10

Passes backwards to from part of the scapular anastomosis

Question 11

Where do the circumflex humeral arteries anastomose?

What do they supply?

Answer 11

Around the surgical neck of the humerus

Glenohumeral joint and the deltoid

Question 12

Which vessels form the axillary vein?

Answer 12

Venae comitantaes and basilic vein. It receives the cephalic vein which pierces the clavipectoral fascia

Question 13

Where do axillary lymph nodes receive lymph from?

Answer 13

Upper limb, breast and the abdominal wall above the umbilicus

Question 14

What are the domains of the brachial plexus?

Answer 14

Roots

Trunks

Divisions

Cords

Branches

Question 15

Where do the trunks of the brachial plexus arise?

Answer 15

Posterior triangle of the neck

Question 16

When do trunks of the brachial plexus split into anterior and posterior divisions?

Answer 16

Apex of the axilla

Question 17

What are the cords of the brachial plexus named according to?

Answer 17

Their relationship to the second part of he axillary artery deep to pectoralis minor

Question 18

Which part of the axillary artery are the branches of the brachial plexus related to?

Answer 18

The third, most distal part

Question 19

What is he path of the ulnar nerve?

Answer 19

Arises from the medial cord of the brachial plexus

Runs along medial aspect of the arm close to coracobrachialis

Pierces intermuscular septum to lie posteriorly in the groove between the olecranon and the medial epicondyle

Passes between 2 heads of FCU

Forms palmar and dorsal cutaneous branches

Question 20

Where does the palmar cutaneous branch of the ulnar nerve arise?

Answer 20

Mid forearm

Question 21

What does the palmar cutaneous branch of the ulnar nerve supply?

Answer 21

Medial side of the palm

Question 22

Where is the dorsal cutaneous branch of the ulnar nerve located?

What does it supply?

Answer 22

Winds around the ulna, deep to FCU

Ulnar one and a half fingers on their dorsal aspects

Question 23

What does the ulnar nerve divide into?

Where does this division occur?

Answer 23

Superficial and deep motor branch

The wrist

Question 24

What vessel does the ulnar nerve run alongside?

Answer 24

Ulnar artery

Question 25

What does the superficial branch of the ulnar nerve supply?

Answer 25

Palmaris brevis and the skin of the ulnar one and a half fingers via 2 digital branches

Question 26

What does the deep terminal branch of the ulnar nerve supply?

Answer 26

Muscles of the hypothenar eminence (flexor digiti minimi, abductor digiti minimi and opponens digiti minimi) , all the palmar and dorsal interossei, the ulnar 2 lumbricals and adductor pollicis

Question 27

What is the path taken by the median nerve from the brachial plexus to the cubital fossa?

Answer 27

Arises from medial and lateral cords of the brachial plexus Runs down anteromedial aspect of the arm with the brachial artery Crosses anterior to artery midway down arm to lie medially before reaching the cubital fossa

Question 28

What is the path taken by the median nerve after it reaches the cubital fossa?

Answer 28

Passes between heads of pronator teres Passes between FDS and FDP Emerges lateral to FDS to become superficial proximal to the wrist

Question 29

Which muscles in the forearm does the ulnar nerve give branches to?

Answer 29

Palmaris longus and flexor carpi radialis

Question 30

What branches are given off by the ulnar nerve? | Proximal to distal

Answer 30

Anterior interosseous branch Palmar cutaneous branch Recurrent muscular branch Digital branches

Question 31

Where does the palmar cutaneous branch of the median nerve arise? What does it supply? How does it enter the hand?

Answer 31

Proximal to the carpal tunnel Skin over the thenar eminence passes deep to the flexor retinaculum

Question 32

What does the recurrent muscular branch of the median nerve supply?

Answer 32

Thenar muscles | flexor pollicis brevis, abductor pollicis brevis and opponens pollicis

Question 33

What do the digital branches of the median nerve supply?

Answer 33

Thumb, index, middle and radial half of the ring fingers

Question 34

Where does the anterior interosseous branch of the median nerve arise? What does it supply?

Answer 34

After the median nerve has pierced pronator teres. Passes distally on the interosseous membrane . Supplies flexor pollicis longus, radial half of FDP and ends at pronator teres

Question 35

What does the radial nerve divide into?

Answer 35

Superficial and deep (posterior interosseous) branch

Question 36

Describe the path of the superficial branch of the radial nerve

Answer 36

Lies deep to brachioradialis and lateral to radial artery Distally, it passes deep to the brachioradialis tendon, curves round the lateral side of the radius and pierces the deep fascia

Question 37

What does the superficial branch of the radial nerve give rise to?

Answer 37

Terminal digital branches

Question 38

What do the terminal digital branches of the radial nerve supply?

Answer 38

Skin on the radial half of the dorsum of the hand, dorsal aspects of the thumb, index, middle and radial half of the ring fingers, but not beyond the distal interphalangeal joints

Question 39

Where does the deep branch of the radial nerve go?

Answer 39

Passes between the heads of the supinator to emerge as the posterior interosseous branch

Question 40

What does the posterior interosseous branch of the radial nerve supply?

Answer 40

Extensors of the wrist and fingers and the supinator

Question 41

What is the breast composed of?

Answer 41

Fat, connective tissue and glandular elements

Question 42

How are glandular elements arranged in the breast?

Answer 42

15-20 lobules, each opening independently onto the surface of the nipple

Question 43

Why is interlobular connective tissue lax in the breast?

Answer 43

To allow for expansion of the glandular elements during pregnancy

Question 44

Where is the breast located?

Answer 44

Attached from the second to sixth ribs, extending laterally from the lateral sternal edge to the mid axillary line

Question 45

What is the level of the nipple in young people?

Answer 45

4th intercostal space

Question 46

What is the axillary tail?

Answer 46

Extension of the breast tissue into the axilla

Question 47

How is the breast innervated?

Answer 47

4th - 6th intercostal nerves

Question 48

How is the nipple innervated? Why is sensory stimulation particularly important here?

Answer 48

4th intercostal nerve Part of suckling reflex (however secretory control is principally hormonal)

Question 49

What is the blood supply to the breast?

Answer 49

Axillary, intercostal and internal thoracic arteries Venous drainage via corresponding veins

Question 50

What percentage of lymphatic drainage from the breast is via axillary nodes?

Answer 50

75%

Question 51

How many axillary nodes are there? How are they organised?

Answer 51

20-30 divided into groups according to location

Question 52

Which groups drain into central axillary nodes? Where are these nodes?

Answer 52

Anterior/pectoral, posterior/subscapular and lateral within axillary fat

Question 53

Where does lymph drain after passing through central nodes in the axilla?

Answer 53

Apical nodes within apex of axilla at the lateral border of the first rib These drain into the subclavian lymph trunk which drains into thoracic duct on the left and the right lymphatic duct on the right