Lecture 12 - Axilla, arm and elbow

Question 1

What is the axilla?

Answer 1

It is a pyramid shaped region

Question 2

What creates the four walls, the base and apex of the axilla?

Answer 2

Four walls

• Anterior: Pectoralis major & minor
• Posterior: Scapula, Teres major, Latissimus dorsi
• Medial: Lateral thoracic wall, Serratus anterior
• Lateral: Humerus, muscle attachments
• Base: Skin of the armpit, Fascia
  
  • Apex: Entrance from base of neck to axilla (1st rib, superior edge of subscapularis)

Question 3

Label this

Answer 3

Question 4

Label this E12 slice

Answer 4

Question 5

Describe the arterial path from the aortic arch until the brachial artery on the right side

Answer 5

Right side of body

1. Subclavian artery branches off brachiocephalic trunk on right side
2. Subclavian artery becomes axillary artery, once it passes first rib
3. The axillary artery becomes the brachial artery, once it passes the lower border of teres major

Question 6

Describe the arterial path from the aoritc arch to the brachial artery on the left side of the body

Answer 6

1. Left subclavian artery branches from the aorta
2. Subclavian artery becomes the axillary artery once is passes the first rib
3. The axillary artery then becomes the brachial artery once it passes the inferior border of teres major

Question 7

Label these key regions through which essential nerves and arteries pass through

Answer 7

Question 8

Which nerve and artery pass through the Quadrangular space?

Answer 8

Axillary nerve

Posterior circumflex

Question 9

Which artery passes through the Triangular space?

Answer 9

Circumflex scapulae artery

Question 10

Which nerve and artery pass through the Triangular interval?

Answer 10

Radial nerve

Profunda brachii artery

Question 11

Which levels of the spine do the roots of the brachial plexus originate?

Answer 11

C5-C8, T1

Question 12

Describe how peripheral nerves are formed from the roots of the spine in the brachial plexus (talk about how they divide and recombine etc)

Answer 12

The roots combine to form trunks

The trunks divide into anterior and posterior divisions

The divisions divide and combine to from cords

The cords divide and combine to form peripheral nerves

Question 13

Which main peripheral nerves are formed by the brachial plexus? (5)

Answer 13

Axillary nerve

Radial nerve

Musculocutaneous nerve

Median nerve

Ulnar nerve

Question 14

Which nerve provides motor supply to the biceps brachii?

Answer 14

Musculocutaneous nerve

Question 15

What levels of the brachial plexus do the following peripheral nerves originate from?

Axillary nerve

Radial nerve

Musculocutaneous nerve

Median nerve

Ulnar nerve

Answer 15

• C5, C6: Axillary
• C5-Th1: Radial
• C5-C7: Musculocutaneous
• C5-Th1: Median
• C8-Th1: Ulnar

Question 16

What are the two synovial hinge joints of the elbow?

Answer 16

• Humeroulnar joint: Trochlea of humerus and trochlear notch of the ulna
• Humeroradial joint: Capitulum and head of radius

Question 17

What are the two movements of the elbow joint?

Answer 17

Flexion & extension

Question 18

Label this

Answer 18

Question 19

Label these ligaments of the elbow

Answer 19

Question 20

What are the flexors of the eblow?

Answer 20

Flexors in arm

• Biceps brachii (insertion at radial tuberosity)
• Brachialis (insertion at coronoid process)

Flexors in forearm

• Brachioradialis
• Pronator teres
• Flexor carpi radialis

Question 21

What are the extensors of the elbow?

Answer 21

Triceps brachii (Insertion at olecranon)

Anconeus (weak extension movement)

Question 22

Label this

Answer 22

Question 23

What function does the interosseus membrane have?

Answer 23

Stabilises both the ulnar and the radius, and allows for muscle attachment

Question 24

What does the oblique cord prevent?

Answer 24

Over supination and pronation

Question 25

What way does the palm face in pronation, and supination?

Answer 25

Supination = palm facing up

Pronation = palm facing down

Question 26

What are the supinator muscles?

Answer 26

Supinator

Biceps brachii (stronger supinator)

Question 27

What are the pronator muscles?

Answer 27

Pronator teres

Pronator quadratus

Question 28

Label this

Answer 28