Axilla and Arm

Question 1

What structures form the anterior walls of the axilla?

Answer 1

Pectoralis Major
Pectoralis Minor
(subclavius)

Question 2

What structures form the posterior walls of the axilla?

Answer 2

Subscapularis
Teres Major
Latissimus Dorsi

Question 3

what structures form the lateral wall of the axilla?

Answer 3

Humerus body

Question 4

What structures form the medial wall of the axilla?

Answer 4

serratus anterior

Question 5

Which nerve roots contribute to the lateral cord of the brachial plexus?

Answer 5

C5, C6 and C7(anterior division of C7 trunk)

Question 6

Which nerve roots contribute to the medial cord of the brachial pleaxus?

Answer 6

C8 and T1

Question 7

What are the 5 main terminal nerves of the brachial plexus and which cords do they arise from?

Answer 7

Musculocutaneous nerve (lateral cord) (C5, C6, C7)
Median nerve (lateral and medial cord) (C6, C7, C8 and T1)
Ulna nerve (Medial cord) (C8, T1)
Axillary nerve (Posterior cord) (C5, C6)
Radial nerve (Posterior cord) (C5-T1)

Question 8

What are the nerve roots of the musculocutaneous nerve and what structures does it innervate?

Answer 8

C5, C6 and C7
innervates:
-coracobrachialis
-biceps brachii
-brachialis

Question 9

What are the nerve roots of the axillary nerve and what structures does it innervate?

Answer 9

C5, C6,
Innervates:
Deltoid
Teres Minor

Question 10

What are the nerve roots of the median nerve?

Answer 10

C6, C7, C8 and T1

Question 11

What structures are innervated by the median nerve?

Answer 11

Anterior Interosseous Branch supplies deep muscles of the anterior compartement:

• Flexor Pollicis Longus
• flexor digitorum profundus (Lateral half )
• Pronator Quadratus

Superficial Compartment:

• Pronator teres
• Flexor Carpi Radialis
• Palmaris Longus
• Flexor Digitorum Superficialis

Muscles of the hand:
1st and 2nd (most radial) lumbricals

(3 Thenar muscles)
Opponens Pollicis
Abducor pollicis brevis
Flexor pollicis brevis

Question 12

what are the nerve roots of the radial nerve and what muscles does it innervate?

Answer 12

C5, C6, C7, C8 and T1
Triceps Brachiii (lateral and medial heads)
Anconeus
Brachioradialis
Extensor carpi radialis longus

• Extensor carpi radialis brevis
• Supinator
• Extensor digitorum
• Extensor digiti minimi
• Extensor carpi ulnaris
• Abductor pollicis
• Extensor pollicis brevis
• Extensor pollicis longus
• Extensor indicis

Question 13

What are the nerve roots of the Ulnar nerve and what muscles does it innervate?

Answer 13

C8 and T1

• Flexor Carpi ulnaris
• Flexor Digitorum Profundus
• Opponens digiti minimi
• Abducor digiti minimi
• Flexor Digiti minimi brevis
• 3rd and 4th Lumbricals of the hand
• Dorsal interossei
• Palmar interossei
• adductor pollicis
• Palmaris brevis

Question 14

When does the axillary artery become the brachial artery?

Answer 14

At the lower margin of teres major

Question 15

What are the branches of the axillary artery that form an anastamoses around the surgical neck of the humerus?

Answer 15

The posterior and anterior humeral circumflex arteries.

the posterior branch can be found quadrangular space alongside the axillary nerve

Question 16

what are the landmarks used to define the beginning and end oft the axillary artery?

Answer 16

upper border = lateral border of 1st rib

lower border = lower margin of teres major

Question 17

Where does the axillary vein lie in relation to the axillary artery?

Answer 17

medially

Question 18

What are the boundaries of the Axillary vein

Answer 18

• starts at lower border of teres major

- becomes the subclavian vein at the lateral border of the 1st rib

Question 19

Describe the course of the cephalic vein.

Answer 19

• Arises over the anatomical snuff box
• Passes onto the antero-lateral side
• Goes up the arm into the delto-pectoral groove

Question 20

Describe the course of the Basilic Vein.

Answer 20

• Arises from the medial side of the dorsal venous network of the hand.
• goes up along the posterior medial side of the forearm
• crosses over onto the anterior surface just below the elbow.
• drains axillary vein. (at inferior border of teres major)