Session 1

Question 1

What are the 3 planes the body can be divided into?

Answer 1

Sagittal - L & R portions
Coronal - Anterior & posterior portions
Transverse - Superior & inferior portions

Question 2

What forms the medial border of the axilla?

Answer 2

Thoracic wall and overlying serratus anterior

Question 3

What forms the anterior wall of the axilla?

Answer 3

Pectoralis major and minor

Question 4

What forms the posterior wall of the axilla?

Answer 4

Subscapularis and inferiorly by the teres major and latissimus dorsi

Question 5

What forms the base of the axilla?

Answer 5

Axillary fossa

Question 6

What forms the apex of the axilla?

Answer 6

First rib, superior border of scapula and posterior border of clavicle

Question 7

What are the main passageways exiting the axilla?

Answer 7

Inferiorly and laterally into the upper limb - main route.
Posteriorly via the quadrangular space into the scapular region
Anteriorly via the clavipectoral triangle into the pectoral region

Question 8

What borders and passes through the quadrangular space?

Answer 8

Superior - subscapularis and teres minor
Inferior - teres major
Laterally - surgical neck of humerus
Medially - long head of triceps brachii
Axillary nerve and posterior circumflex humeral artery (a branch of the axillary artery) leave.

Question 9

What borders and passes through the clavipectoral triangle?

Answer 9

Bounded by the deltoid, pectoralis major and clavicle. Cephalic vein enters and the medial and lateral pectoral nerves leave.

Question 10

What are the main contents of the axilla?

Answer 10

Axillary artery, axillary vein, brachial plexus, biceps brachii and coracrbrachialis tendons and axillary lymph nodes

Question 11

Describe the location and function of the axilla

Answer 11

Inferior to the glenohumeral joint and superior to the axillary fascia. It provides a passageway for neurovascular structures that serve the upper limb.

Question 12

What forms the lateral border of the axilla?

Answer 12

Intertubercular groove of the humerus

Question 12

How does the size and shape of the axilla vary?

Answer 12

Size decreases with arm abduction

Question 13

What are the symptoms and causes of thoracic outlet syndrome?

Answer 13

The vessels and nerves in the apex of the axilla become compressed between the bones by trauma or repetition. Symptoms include pain, tingling, weakness and discolouration.

Question 14

What is the axillary sheath?

Answer 14

A sleeve-like extension of the cervical fascia that envelops the neurovascular structures of the axilla.

Question 15

Which muscles form the anterior and posterior folds of the axilla?

Answer 15

Anterior - pectoralis major

Posterior - latissimus dorsi and teres major

Question 16

Where does the axillary artery begin and end?

Answer 16

Begins at the lateral border of the first rib (from the subclavian artery) and ends at the inferior border of the teres major.

Question 17

How is the axillary artery divided?

Answer 17

Into 3 parts by the pectoralis minor

Question 18

What branches from the first part of the axillary artery?

Answer 18

Superior thoracic artery

Question 19

What branches from the second part of the axillary artery?

Answer 19

The thoraco-acromial artery and lateral thoracic artery

Question 20

What branches from the third part of the axillary artery?

Answer 20

Posterior and anterior circumflex humeral arteries (encircle surgical neck of humerus - sometimes have a common trunk) and the subscapular artery (largest branch of axillary artery).

Question 21

What are the complications of axillary artery aneurysm?

Answer 21

It can compress the trunks of the brachial plexus, causing pain and anesthesia (loss of sensation) in the areas of skin supplied by the affected nerves.

Question 22

What forms the axillary vein?

Answer 22

The union of the basilic and brachial vein

Question 23

What are the 5 groups of lymph nodes in the axilla?

Answer 23

Pectoral, subscapular, humeral, central and apical

Question 24

Location, number and function of the pectoral lymph nodes:

Answer 24

3-5 nodes in the medial wall wall of the axilla. They receive lymph from the anterior thoracic wall, including most of the breast.

Question 25

Location, number and function of the subscapular lymph nodes:

Answer 25

6-7 nodes along the posterior axillary fold and subscapular blood vessels. They receive lymph from the posterior thoracic wall and scapular region.

Question 26

Location, number and function of the humeral lymph nodes:

Answer 26

4-6 nodes in the lateral wall of the axilla, posterior to the axillary vein. They receive the majority of lymph from the upper limb.

Question 27

Location, number and function of the central lymph nodes:

Answer 27

3-4 large nodes near the base of the axilla. They receive lymph via efferent vessels from the pectoral, subscapular and humeral axillary lymph node groups.

Question 28

Location and function of the apical lymph nodes:

Answer 28

Apex of the axilla - receive lymph from efferent vessels of the centra axillary lymph nodes, therefore from all axillary lymph nodes. They also receive lymph from the lymphatic vessels that accompany the cephalic vein.

Question 29

What happens to efferent vessels from the apical axillary nodes?

Answer 29

They travel through the cervico-axillary canal then converge to form the subclavian lymphatic trunk. The right subclavian trunk continues to form the right lymphatic duct and enters at the right venous angle (junction between internal jugular and subclavian veins). The left subclavian trunk drains directly into the thoracic trunk.

Question 30

What are the main causes of enlargement of axillary lymph nodes?

Answer 30

Infection of the upper limb resulting in lymphangitis, the humeral group is usually the first affected. Warm, red and tender streaks appear on the skin of the upper limb.
Infection of the pectoral region and breast.
Metastasis of breast cancers.

Question 31

When is axillary lymph node dissection important and what are the possible complications?

Answer 31

Important for the staging of breast cancers.
Lymphatic drainage of the upper limb may be impeded - leading to lymphoedema (swelling of accumulated lymph in the subcutaneous tissue). There is also a risk of damage to the long thoracic nerve (winging of the scapula) and thoracodorsal nerve (weakened adduction and medial rotation).

Question 32

What forms the brachial plexus?

Answer 32

The union of the anterior rami of the last 4 cervical (C5-8) and first thoracic (T1) spinal nerves.

Question 33

What are the five parts of the brachial plexus?

Answer 33

Roots, trunks, divisions, cords, branches. (Rugby Teams Drink Cold Beer).

Question 33

Describe the formation and pathway of the roots of the brachial plexus

Answer 33

Paired spinal nerves arise from each vertebral level and leave the spinal cord via the intervertebral foramina of the vertebral column.
Each nerve then divides into anterior and posterior nerve fibres. The roots of the brachial plexus are formed by the anterior divisions of the spinal nerves C5-T1.
After their formation these nerves pass between the anterior and medial scalene muscles to enter the base of the neck.

Question 34

Where do the trunks of the brachial plexus form and how are they named?

Answer 34

Formed at the base of the neck and they are named by their anatomical position (superior, middle and inferior).

Question 36

What is the route and fate of the trunks of the brachial plexus?

Answer 36

They move laterally, crossing the posterior triangle of the neck. Each trunk divides into anterior and posterior divisions as the plexus passes through the cervico-axillary canal (3 anterior and 3 posterior).

Question 37

How are the cords of the brachial plexus named?

Answer 37

In relation to the axillary artery.

Question 38

What can cause damage to the upper brachial plexus (Erb’s palsy)?

Answer 38

When there is an excessive increase in the angle between the neck and shoulder - this can result from a difficult birth or shoulder trauma.

Question 39

What are the:
     Nerves affected
     Muscles paralysed
     Impaired motor functions
     Impaired sensory functions
for Erb's palsy?

Answer 39

Nerves affected - nerves derived solely from C5 or C6 roots; musculocutaneous, axillary, suprascalular and nerve to subclavius.
Muscles paralysed - supraspinatus, infraspinatus, subclavius, biceps brachii, brachialis, coracrbrachialis, deltoid and teres minor.
Impaired motor functions - abduction, lateral rotation and flexion at shoulder. Supination of forearm.
Impaired sensory functions - loss of sensation down lateral side of arm (axillary and musculocutaneous).

Question 40

What is the usual clinical appearance for Erb’s palsy?

Answer 40

Waiters tip position - Limb hangs limply, medially rotated and pronated forearm.

Question 41

What can cause damage to the lower brachial plexus (Klumpke palsy)?

Answer 41

Excessive abduction of the arm - eg a person catching a branch as they fall from a tree.

Question 42

What are the:
     Nerves affected
     Muscles paralysed
     Impaired sensory functions
for Klumpke palsy?

Answer 42

Nerves affected - nerves derived from the C8 and T1 roots
Muscles affected - all the small muscles of the hand
Impaired sensory functions - loss of sensation along the medial side of the arm

Question 43

What is the usual clinical appearance for Kumpke palsy?

Answer 43

The metacarpophalangeal joints are hyperextended and the interphalangeal joints and flexed (clawed appearance).

Question 44

What is the cause and observation for “winging of the scapula”?

Answer 44

Caused by damage to the long thoracic nerve so the serratus anterior becomes paralysed. When pushing with the affected limb, the scapula is no longer held against the rib cage and protrudes out of the back.

Question 45

What is the importance of the many arterial anastomoses around the scapula?

Answer 45

When ligation of a lacerated subclavian or axillary artery is necessary or when there is vascular stenosis of axillary artery. The direction of blood flow in the subscapular artery is reversed, enabling blood to reach the third part of the axillary artery.