Axilla And Brachial Plexus

Question 1

What artery/vein are contained in the axilla?

Answer 1

Axillary artery and vein

Question 2

Subclavian artery becomes axillary artery where?

Axillary artery becomes brachial artery past ___

Answer 2

At the first rib

Teres major

Question 3

Boundaries of the axilla:

Apex =

Base (inferior) =

Anterior wall=

Posterior wall=

Medial wall =

Answer 3

Apex = borders of clavicle, scapula, and first rib

Base= axillary folds (lower border of pec major and lower border of teres major and lats), thoracic wall

Anterior= pec major/minor and subclavius

Posterior= subscapularis, teres major, lats, scapula

Medial = upper 4-5 ribs, intercostal muscles, serratus anterior

Question 4

Axillary lymphatics

1. Pectoral (anterior) nodes:
2. Subscapular (posterior) nodes:
3. Humeral (lateral) nodes:

Answer 4

1. Lymph vessels from anterior thoracic and abdominal walls, lateral breast
2. Lymph vessels from the back
3. Lymph vessels from upper limb

Question 5

1. Axillary nerve provides SENSORY innervation for ?
2. Radial nerve provides SENSORY innervation for?
3. Musculocutaneous nerve provides SENSORY innervation for?
4. Median nerve provides SENSORY innervation for?
5. Ulnar nerve provides SENSORY innervation for?

Answer 5

1. Small area of lateral/proximal arm
2. Posterior arm, forearm, and hand
3. Lateral forearm
4. Lateral hand and fingers (half of ring, middle, pointer, and thumb)
5. Medial hand and fingers (half of ring and all of pinky)

Question 6

What are the subdivisions of all the parts of the brachial plexus:

1. Roots
2. Trunks
3. Divisions
4. Cords
5. Nerves

Answer 6

1. C5-T1
2. Superior, middle, inferior
3. Anterior/ventral and posterior/dorsal
4. Lateral cord, posterior cord, medial cord
5. Musculocutaneous, axillary, radial, median, and ulnar

Question 7

What nerves are supplied by the dorsal division?

Ventral division?

Answer 7

Dorsal = radian and axillary

Ventral = musculocutaneous, median, and ulnar

Question 8

Four nerves that are short branches of the supraclavicular ?

What muscles do these branches innervate?

Answer 8

Dorsal scapular nerve: levator scap, rhomboid major and minor

Long thoracic nerve: serratus anterior

Subscapular nerve: subscapularis and teres major

Suprascapular nerve: supra/infraspinatus

Question 9

Axillary nerve motor innervations?

Axillary nerve sensory innervations?

Answer 9

Motor- deltoid and teres minor

Sensory- small area of lateral/proximal arm

Question 10

Radial nerve motor innervations?

Radial nerve sensory innervations?

Answer 10

Motor- extensors in arm and forearm (no intrinsic hand muscles)

Sensory- posterior arm, forearm, and hand

Question 11

Pectoral group- what part innervates what muscles?

Answer 11

Lateral and medial pectoral nerve innervate pec major

Medial pectoral nerve innervates pec minor

Question 12

Sensory and motor innervations of the musculocutaneous nerve

Answer 12

Sensory- lateral forearm

Motor- flexors in arm

Question 13

Median nerve motor and sensory innervations

Answer 13

Motor - most flexors in forearm, most extrinsic hand flexors, thenar muscles, 1/2 lumbricals

Sensory- lateral hand and fingers

Question 14

Ulnar nerve motor and sensory innervations?

Answer 14

Motor- 1 1/2 flexor in forearm, all intrinsic hand muscles (except thenar muscles), 1/2 lumbricals

Sensory- medial hand and fingers

Question 15

Posterior cord is formed by what?

Answer 15

By the posterior divisions of the 3 trunks

Question 16

Posterior cord branches off to what nerves of the brachial plexus?

Answer 16

Axillary and radial

Question 17

The lateral cord divides into what nerves?

Answer 17

The musculocutaneous nerve and median nerve (lateral root of median nerve)

Question 18

Medial cord divides into what nerves?

Answer 18

Ulnar nerve and the median nerve (medial root of median nerve)

Question 19

Two nerves that branch off of the roots?

What roots do they branch off of?

Answer 19

Dorsal scapular nerve (C5)

Long thoracic nerve (C5-C7)

Question 20

What nerves arise from the superior trunk?

Answer 20

Suprascapular nerve and nerve to subclavius

Question 21

No nerves arise from the ?

Answer 21

Divisions

Question 22

Each cord gives off some nerves

1. What nerves do the lateral cord give off?
2. Posterior cord?
3. Medial cord?

Answer 22

1. Lateral pectoral nerve
2. Upper middle and lower subscapular nerve (middle aka thoracodorsal nerve)
3. Medial pectoral nerve, medial brachial cutaneous nerve, and medial antebrachial cutaneous nerve

Question 23

Clinical aspects of brachial plexus:
Upper brachial plexus injury occurs from?

What kind of paralysis could this form? Presentation?

Answer 23

Extreme lateral flexion of the head, especially if the shoulder is simultaneously depressed (can also happen during birth)

~ stress on C5/C6 root

Erb-duchenne paralysis: waiters tip position

Question 24

Lower brachial plexus injury occurs from?

What kind of paralysis? Presentation?

Answer 24

Extreme abduction (if someone was falling off a cliff and reaches up to hold a branch and hang) (can also occur during birth)
~stress on C8/T1

Klumpkes paralysis= claw hand