1. Brachial Plexus & Axilla

Question 1

What are the origins of the pectoralis major?

Answer 1

1. Clavicular head - anterior surface of the medial clavicle.
2. Sternal head- anterior sternum,upper 6 costal cartilages and apaneurosis of ext. oblique

Question 2

What is the innervation of the pectoralis major?

Answer 2

Lateral and medial pectoral nerves

Question 3

What is the insertion point of the pectoralis major?

Answer 3

Lateral lip of intertubercular sulcus on humerus

Question 4

What is the action of the pectoralis major?

Answer 4

• Adducts and medial rotates upper limb

- Clavicular head flexes the upper limb

Question 5

What is the origin of the pectoralis minor?

Answer 5

3-5 ribs

Question 6

What is the insertion of the pectoralis minor?

Answer 6

Coracoid process

Question 7

What nerve supplies the pectoralis minor?

Answer 7

Medial pectoral nerve

Question 8

What action does the pectoralis minor cause?

Answer 8

Stabilises scapula

Draws scapular anterioinferiorly towards ribs

Question 9

What nerve innervates the coracobrachialis?

Answer 9

Musculocutaneous nerve

Question 10

What is the origin of the coracobrachialis?

Answer 10

Coracoid process

Question 11

Where does the coracobrachialis insert?

Answer 11

Medial side of the humerus at the level of the deltoid tubercle.

Question 12

What is the action of the coracobrachialis?

Answer 12

Flexion of the arm at the shoulder joint

Weak adduction

Question 13

What are the 3 origins of the deltoid?

Answer 13

Anterior: clavicle
Lateral: acromion
Posterior: spine of scapula

Question 14

Where does the deltoid insert?

Answer 14

Deltoid tuberosity of humerus

Question 15

What nerve supplies the deltoid muscle?

Answer 15

Axillary

Question 16

What action does the anterior part of the deltoid muscle cause?

Answer 16

Flexion of the arm at the shoulder joint

Question 17

What action does the lateral section of the deltoid cause?

Answer 17

Abduction of the arm at the shoulder joint

Question 18

What does the posterior section of the deltoid cause?

Answer 18

Extension of the arm at the shoulder joint

Question 19

What is the origin of the serratus anterior?

Answer 19

Ribs 2-8

Question 20

What is the insertion of the serratus anterior?

Answer 20

The rib facing surface of medial border of scapula

Question 21

What nerve supplies the serratus anterior?

Answer 21

long thoracic nerve

Question 22

What are the actions of the serratus anterior?

Answer 22

Rotates the scapular, allowing arm to be raised over 90 degrees.
Holds the scapula against the rib cage

Question 23

What nerve roots contribute to the musculocutaneous nerve?

Answer 23

C5,C6,C7

Question 24

Which nerve roots form the axillary nerve?

Answer 24

C5 and C6

Question 25

What nerve roots form the median nerve?

Answer 25

C6,C7,C8,T1

Question 26

Which nerve receives contributions from all 5 routes?

Answer 26

Radial nerve

Question 27

Which nerve roots contribute to the ulnar nerve?

Answer 27

C8, T1

Question 28

What are the trunks of the brachial plexus?

Answer 28

Superior, Middle and Inferior

Question 29

What are the divisions of the brachial plexus?

Answer 29

Anterior and posterior

Question 30

What are the cords of the brachial plexus?

Answer 30

Lateral, posterior and medial

Question 31

What are the branches of the brachial plexus?

Answer 31

``` Musculocutaneous nerve Axillary nerve Median nerve Radial nerve Ulnar nerve ```

Question 32

What anatomical landmarks divide the axillary artery into its 3 sections?

Answer 32

Subclavian artery until it passes the FIRST RIB where it become the axillary artery until it passes the TERES MAJOR where it becomes the brachial artery.

Question 33

Which muscles form the anterior border of the axilla?

Answer 33

Pectoralis major and minor

Question 34

What is the posterior border of the axilla?

Answer 34

Subscapularis, teres major and latissimus dorsi

Question 35

What muscles form the medial wall of the axilla?

Answer 35

Serratus anterior

Question 36

What are the contents of the fibrous axillary sheath?

Answer 36

Axillary artery Axillary vein Brachial plexus

Question 37

Describe the contents of the axilla.

Answer 37

Axillary artery, brachial plexus cords, axillary vein, tendon of biceps brachii and coracobrachialis Axillary lymph nodes

Question 38

The lateral, medial and posterior cords are names according to their relationship with which vessel?

Answer 38

Axillary artery

Question 39

What structure is the lateral border of the axilla?

Answer 39

The intertubercular sulcus of humerus

Question 40

What are the 5 principle groups of axillary lymph nodes?

Answer 40

``` Pectoral Sub-scapular Humeral Central Apical ```