Axillary Nerve

Question 1

Axillary nerve arises from which cord of brachial plexus?

Answer 1

Posterior

Question 2

Sensory function of axillary nerve?

Answer 2

Gives superior (upper) lateral cutaneous nerve of arm
Which innervates the skin over lower deltoid region
(Regimental badge region)

Question 3

Axillary nerve lies between which artery and which muscle?

Answer 3

Between
Axillary artery &
Subscapularis muscle

Question 4

Axillary nerve exits the axilla at?

Answer 4

Inferior border of subscapularis muscle by :

Quadrangular Space

Question 5

What are the boundaries of quadrangular space?

Answer 5

laterally
Surgical neck of humerus
Superiorly
Subscapularis muscle (Teres minor)
Medially
Long head of the triceps brachii
Inferiorly
Teres major

Question 6

What passes through the quadrangular space other than axillary nerve?

Answer 6

Posterior humeral circumflex artery
Arises from axillary artery

Question 7

What are the divisions of axillary nerve as it leaves axilla?

Answer 7

Anterior terminal branch
Posterior terminal branch

Question 8

The terminal branch of axillary nerve that supplies the sensory innervation? And to what structure it supplies?

Answer 8

Superior lateral cutaneous nerve
- a continuation of posterior terminal branch of axillary nerve
-it innervates the skin of inferior part of deltoid
(Regimental badge area)

Question 9

Motor innervation is supplies by which branch of axillary nerve? And to what?

Answer 9

Anterior Terminal branch
Supplies to:
Deltoid

Posterior Terminal branch
Supplies to:
Teres minor

Question 10

Axillary nerve arises from spinal roots?

Answer 10

C5 and C6

Question 11

After leaving axilla, The axillary nerve before division, passes ________ to the surgical neck of humerus

Answer 11

Medially

Question 12

Teres minor is innervated by?
And deltoid is innervated by

Answer 12

Teres minor - Posterior terminal branch of axillary nerve

Deloid - Anterior terminal branch of axillary nerve

Question 13

Cause of axillary nerve damage?

Answer 13

Trauma to proximal humerus or shoulder girdle:
Surgical neck fracture of humerus

Question 14

Effect of axillary nerve damge?

Answer 14

Loss of motor functions of
Deltoid(Affected limb unable to be abducted beyond 15°)
Teres minor

Loss of sensation over regimental badge area

Question 15

If there is numbness in distribution of axillary nerve, the branch that is most likely affected is?

Answer 15

Posterior terminal branch of axillary nerve