Axilla/Brachial Plexus

Question 1

Describe the borders of the Axilla region

Answer 1

Roof = continuous with root of neck

Floor = fascia/skin

Anterior Wall = pec major, pec. minor, subclavius, clavipectoral fascia

Posterior Wall = latissiumus dorsi, scapula, and teres major, subscapularis, and long head of triceps

Medial Wall= Serratus Anterior

Lateral Wall = intertubercular groove

Question 2

What are the attachments of Pec. Major?

Answer 2

Clavicular head, sternal head and intertubercular groove

Question 3

What is the nerve supply to the pectoralis major?

Answer 3

medial and lateral pectoral nerves

Question 4

What actions is Pec. Major responsible for?

Answer 4

Flexion, adduction and medial rotation

Question 5

What innervates the pectoralis minor?

Answer 5

the medial pectoral nerve

Question 6

What are the attachments of the latissimus dorsi?

Answer 6

pelvis, spine, and scapula

Question 7

What nerve innervates the latissimus dorsi?

Answer 7

Thoracodorsal Nerve (C6,7,8)

Question 8

What are the attachments of the serratus anterior?

Answer 8

upper 8 ribs then runs back to attache to the medial border of the scapula - it pulls the scapula forwards

Question 9

What innervates the serratus anterior?

Answer 9

The long thoracic nerve of bell

Question 10

What will we see if the long thoracic nerve is damaged?

Answer 10

We will see “winging” of the scapula due to reduced function of the serratus anterior muscle

Question 11

What are the contents of the axillary?

Answer 11

Artery, vein, lymph nodes, and brachial plexus

Question 12

Where does the Axillary artery start? Where does it end?

Answer 12

The Axillary artery only extends from the inlet of the Axilla to the floor of the Axilla

Question 13

What are the branches of the Axillary Artery?

Answer 13

S- superior thoracic

A- Acromio thoracic

L- Lateral Thoracic

S- Subscapular

A- Anterior circumflex humeral

P- Posterior Circumflex humeral

Question 14

What muscle does the second part of the axillary artery pass over?

Answer 14

Pectoralis Minor

Question 15

What lies inferior to the 3rd part of the axillary artery?

Answer 15

The teres Minor

Question 16

What does the axillary artery become after it exits the axillary?

Answer 16

It becomes the Brachial artery

Question 17

Describe the lymphatic system of the axilla

Answer 17

There are 6

3 at base= humeral (lateral), Pectoral (anterior), Subscapular (posterior)

Then they all drain into Central Node

then superiorly is the Apical node

then superior to the axilla is the Subclavian node

Question 18

What spinal nerves form the brachial plexus ?

Answer 18

Spinal nerves from C5 - T1

Question 19

Describe the divisions of the brachial Plexus !

Answer 19

Roots (between scalene muscles)

Trunks (neck)

Divisions (posterior to clavicle)

Cords (axilla)

Branches

Question 20

What nerves exit at the roots C5,6,7?

Answer 20

Dorsal Scapular

Subclavius

and Long Thoracic

Question 21

What nerve exits the brachial plexus at the trunk?

Answer 21

Suprascapular

Question 22

What are the three cords of the brachial plexus and how are they named?

Answer 22

Lateral (lateral to Axillary artery)

Medial (medial to axillary artery)

Posterior (posterior to axillary artery)

Question 23

Name the branches of the Lateral cord of the brachial plexus

Answer 23

2 LM

Lateral pectoral

Lateral head of median nerve

Musculocutaneous

Question 24

Name the branches of the posterior cord of the brachial plexus

Answer 24

STARS

subscapular (upper)

Thoracodorsal

Axillary

Radial

Subscapular (lower)

Question 25

Name the branches of the medial cord of the brachial plexus

Answer 25

4MU

Medial pectoral

medial head of median nerve

medial cutaneous nerve of arm

medial cutaneous nerve of forearm

Ulnar nerve

Question 26

When we see the “M” shape in the brachial plexus - what are we looking at?

Answer 26

We are looking a the medial and Lateral cord of the plexus?

Question 27

Where are you likely to get a dislocation of your humorus? What are the implications of this?

Answer 27

You’re likely to get an Anterior dislocation (scapula is posterior) - clinically this is dangerous b/c of the presence of the axillary nerve which wraps around the neck of the humerus

Question 28

What is Erb’s Palsy - what roots are effected?

Answer 28

Erb’s palsy = C5,6

Causes ‘waiter’s tip’ deformation = medial rotation, forearm extension, and pronation

Question 29

What is Klumpke’s paralysis? What nerve roots are effected?

Answer 29

It effects roots C8- T1

It results in a claw hand

Question 30

What nerves are often damaged in breast surgery?

Answer 30

Long thoracic nerve of bell

Question 31

What movements occur at the sternoclavicular joint?

Answer 31

The sternoclavicular joint has a large degree of mobility. There are several movements that require joint involvement:

Elevation of the shoulders –

Depression of the shoulders –

Protraction of the shoulders –

Retraction of the shoulders –

Rotation – when the arm is raised over the head by flexion the clavicle rotates passively as the scapula rotates. This is transmitted to the clavicle by the coracoclavicular ligaments