Axillary Region

Question 1

The brachial plexus runs through this structure that leads to the posterior triangle of the neck. What is this structure bounded by?

Answer 1

Cervicoaxillary canal

Clavical anteriorily
Scapula Posterally
1st rib medially

Question 2

What nerve is the lateral branch of the 2nd intercostal nerve (T2) that supples the chest wall and continues to the arm

Answer 2

Intercostobrachial nerve

Question 3

What artery begins at the lateral border of the first rib (and is a continuation of the subclavian artery)?

How many branches are there off of this artery?

Answer 3

Axillary Artery

6 Branches

Question 4

The first artery that branches off the axillary artery in region 1

Answer 4

The superior thoracic artery

Question 5

The second and third arteries branching off the axillary artery in region 2 (covered by the pectoralis minor

Answer 5

Thoracoacromial Artery (trunk)

Lateral thoracic artery (supplies lateral breast)

Question 6

The fourth, fifth, and sixth arteries branching off the axillary artery in region 3

Answer 6

Subscapular Artery (divides into the circumflex scapular (anastomoses with supra scapular) artery and throacodorsal artery (to latissimus)

Posterior Circumflex Humeral Artery (quadrilateral space, then anastomises with anterior circumflex humeral artery)

Anterior Circumflex Humeral Artery

Question 7

The posterior triangle of the neck is formed by the?

Answer 7

Trapezeus posteriorly
Sternocleidomastoid medially
Clavical inferiorly

Question 8

The brachial plexus is formed by what nerves?

What part of the nerves form the Roots of the brachial plexus?

Answer 8

C5 -C8 and T1

The ventral roots (rami) form the Roots of the brachial plexus

Question 9

The five segments of the brachial plexus

Answer 9

Roots - Trunks - Divisions - Cords - Branches (Nerves)

Question 10

The trunks of the brachial plexus

Answer 10

Superior C5-C6
Middle C7
Inferior C8-T1

Question 11

The divisions of the Brachial plexus

Answer 11

Anterior and posterior divisions sections of the Divisions are the same as the Trunks

Superior C5-C6
Middle C7
Inferior C8-T1

Question 12

The cords of the brachial plexus

Answer 12

Lateral is C5, C6, C7

Posterior C5-T1

Medial C8 and T1

Question 13

What are the major (clinically important) nerve branches out of the brachial plexus?

Answer 13

Musculocutaneous NErve
Median Nerve
Axillary Nerve
Radial Nerve
Ulnar Nerve

Question 14

The lateral chord gives rise to which nerves?

Answer 14

Lateral pectoral nerve (pec major)
Musculocutaneous nerve

Lateral root joins with the medial root and gives rise to the median nerve

Question 15

The Posterior cord gives rise to which nerves?

Answer 15

Axillary (deltoid, teres minor)
Radial
Thoracodorsal Nerve (latissimus)
Upper and lower sub scapular nerves (subscapularis, trees major)

Question 16

The Medial Cord gives rise to which nerves?

Answer 16

The medial root joins with the lateral root and gives rise to the median nerve

Medial Pectoral nerve (pec major and minor)
Medial brachial cutaneous nerve
Medial antebrachal cutaneous nerve

Question 17

Long thoracic nerve is from what region of the brachial plexus? What muscle does it innervate? What is clinically important about this nerve?

Answer 17

The Roots of C4, C6, and C7 (ventral rami)

Serratus Anterior

Winged Scapula

Question 18

An injury causing an increase in angle between the neck and the shoulder (resulting from fall, car crash, delivery of baby, etc) could injure which spinal roots? What muscle do the innervate?

What is the clinical presentation?

What is this called?

Answer 18

C5 and C6

Lateral rotators (teres minor, infraspinatus)
Abductors of arm (supraspinatus, deltoid)

Arm will be medially rotated and adducted
Waiters Tip (loose lateral rotation of arm)

Upper brachial plexus injury (Erb-Duchenne Palsy)

Question 19

An injury causing upper limb to be pulled superiorly (baby during delivery, or person hanging form cliff) causes what injury?

Answer 19

Lower brachial plexus injury (Klumpke paralysis)

Injury to C8-T1

Ulnar Nerve
Median Nerve

Causes Atrophy of intrinsic (short) muscles of hand
Claw Hand - Paralysis of hand

Question 20

The nerves that supply sensory information of the medial portions of upper extremity

Answer 20

Medial cutaneous nerve of arm

Medial cutaneous nerve of forearm

Question 21

Mucle located on inner (anterior) surface of scapula and is part of the rotator cuff

Innervated by?

Answer 21

Subscapularis

Innervated by upper and lower sub scapular nerves (posterior cord of brachial plexus)

Question 22

An injury causing an increase in angle between the neck and the shoulder (resulting from fall, car crash, delivery of baby, etc) could injure which spinal roots? What muscle do the innervate?

What is the clinical presentation?

What is this called?

Answer 22

C5 and C6

Lateral rotators (teres minor, infraspinatus)
Abductors of arm (supraspinatus, deltoid)

Arm will be medially rotated and adducted
Waiters Tip (loose lateral rotation of arm)

Upper brachial plexus injury (Erb-Duchenne Palsy)

Question 23

An injury causing upper limb to be pulled superiorly (baby during delivery, or person hanging form cliff) causes what injury?

Answer 23

Lower brachial plexus injury (Klumpke paralysis)

Injury to C8-T1

Ulnar Nerve
Median Nerve

Causes Atrophy of intrinsic (short) muscles of hand
Claw Hand - Paralysis of hand

Question 24

The nerves that supply sensory information of the medial portions of upper extremity

Answer 24

Medial cutaneous nerve of arm

Medial cutaneous nerve of forearm

Question 25

Mucle located on inner (anterior) surface of scapula and is part of the rotator cuff

Innervated by?

Answer 25

Subscapularis

Innervated by upper and lower sub scapular nerves (posterior cord of brachial plexus)

Question 26

What cord mainly supplies extensors?

Exception?

Answer 26

Posterior Cord

Except for brachioradialis

Question 27

Glenohumoral joing dislocation

Answer 27

Usually occurs in inferior direction (slightly anterior) do to a sudden blow when fully abducted or to excessive lateral rotation of the upper extremity.