3.2

Question 1

Surface anatomy of axillary boundaries and contents

Answer 1

Anterior axillary fold: pectoralis major
Posterior axillary fold: latissimus and teres major
Axillary lines: anterior, posterior, mid
Digitations of serratus anterior

Question 2

Apex of axillary boundaries

Answer 2

Cervicoaxillary canal
Bound by:
- clavicle
- 1st rib
- superior border of scapula

Question 3

Base of axillary boundaries

Answer 3

concave skin and fascia

Question 4

Walls of axillary boundaries

Answer 4

Anterior: pec major and minor
Posterior: scapularis, teres major, latissimus dorsi
Medial: ribs 1-4, serratus anterior
Lateral: intertubecular groove of humerus

Question 5

Label

Answer 5

Question 6

What are the 3 parts of the axillary artery?

Answer 6

Lateral border of 1st rib to medial border of pec minor (1 branch)
Posterior to pec minor (2 branches)
Lateral border of pec minor to lateral border of teres major (3 branches)

Question 7

What is the 1st part of the axillary artery?

Answer 7

Lateral border of 1st rib to medial border of pec minor
1 branch - superior thoracic artery
Supplies 1st and 2nd intercostal spaces

Question 8

What is the 2nd part of the axillary artery?

Answer 8

2 branches
Thoracoacromial a. - Short trunk which immediately divides into 4 small branches that diverge to supply neighboring structures
1) Clavicular br.
2) Acromial br.
3) Pectoral br.
4) Deltoid br.
Lateral thoracic a. - Supplies lateral thoracic wall and muscles

Question 9

What is the 3rd part of the axillary artery?

Answer 9

1. Anterior circumflex humeral a.
   - A small branch which winds around anterior aspect of surgical neck of humerus.
2. Posterior circumflex humeral a.
   - A much larger branch which passes posteriorly through quadrangular space (with axillary n.) and winds around posterior aspect of surgical neck of humerus.
   - Supplies deltoid m. and shoulder joint; anastomoses with ant. circumflex humeral a.
3. Subscapular a.
   - Largest branch of axillary a.
   - Supplies muscles of posterior wall of axilla.
   - It ends by dividing into two branches:
   1) circumflex scapular a., which winds around lateral border of scapula to reach infraspinous fossa where it participates in scapular anastomosis
   2) thoracodorsal a., which runs with nerve of same name to latissimus dorsi m.

Question 10

Branches of axillary artery

Answer 10

Form a rich anastomosis around the scapula
Dorsal scapular (variable)
Suprascapular (from the thyrocervical trunk)
Circumflex scapular (from the subscapular)
Thoracodorsal (also from the subscapular)

The subclavian, axillary, and brachial aa. are one continuous a. that changes names. The scapular anastomosis is formed by the branches from these (this) artery.

Question 11

Brachial plexus in reference to clavicle

Answer 11

Supraclavicular (roots and trunks)
Infraclavicular (cords and terminal branches)

Question 12

Draw the brachial plexus

Answer 12

Question 13

Label brachial plexus nerves

Answer 13

Question 14

Brachial plexus injuries

Answer 14

Commonly either upper or lower plexus
- Upper: C5 and C6
- Lower: C8 and T1

Question 15

Brachial plexus relationships

Answer 15

Plexus passes between anterior/middle scalene muscles
Plexus passes deep to pec minor/coracoid process

Question 16

Myotomes for brachial plexus

Answer 16

Question 17

Brachial plexus blocks

Answer 17

Ultrasound guided local administration of anesthesia to brachial plexus.
- Interscalene blocks
- Supraclavicular blocks
- Infraclavicular blocks
- Axillary blocks

Question 18

Interscalene block

Answer 18

target the C5-C7 roots as they pass between the anterior and middle scalene mm. It usually does not anesthetize the C8-T1 roots. This block is typically performed for shoulder surgeries.

Question 19

Supraclavicular blocks

Answer 19

target the trunks which are in close proximity and can all be affected by the anesthesia. This block is most useful for surgeries of the arm, elbow, and forearm.

Question 20

Infraclavicular blocks

Answer 20

target the cords which are also in close proximity and can all be potentially affected by anesthesia. This block is used for lower arm, elbow, forearm, and hand surgeries.

Question 21

Axillary blocks

Answer 21

target the terminal branches. It is also used for lower arm, elbow, forearm, and hand surgeries.