Exam 3 - Axilla & Brachial Plexus I & II

Question 1

The basilic vein is found near what nerve?

Answer 1

Medial antebrachial cutaneous nerve (in deep brachial fascia)

Question 2

Function of pectoralis major

Answer 2

Flexes, adducts, medial rotates humerus

Question 3

Function of pectoralis minor

Answer 3

Draws scapula down and forward, stabilizes it

Question 4

3 structures of deltopectoral triangle

Answer 4

Cephalic vein, thoracoacromial artery, lateral pectoral nerve

Question 5

The anterior axillary fold, visible in people with good musculature, is found on the lateral border of what muscle?

Answer 5

Pectoralis major

Question 6

What nerve passing through the medial wall of the axilla can convey referred pain from the heart?

Answer 6

Lateral cutaneous branch of the 2nd/3rd intercostal nerve (from the intercostobrachial nerve)

Question 7

The anterior division of the brachial plexus is responsible for _______; the posterior division of the brachial plexus is responsible for _____.

Answer 7

Flexors; extensors

Question 8

The brachial plexus lies on top of what artery?

Answer 8

Axillary artery

Question 9

Difficult delivery of a newborn or motorcycle injuries may lead to a lesion of the upper trunk of the brachial plexus. What are the four nerves associated with this type of palsy?

Answer 9

Suprascapular (supraspinatous/infraspinatous); nerve to subclavius (subclavius); musculocutaneous (coracobrachialis, biceps brachii, brachialis); axillary (deltoid, teres minor)

Question 10

What are four primary symptoms of Erb-Duchenne Palsy (lesion of the upper trunk)?

Answer 10

Upper limb hangs limply (NO abduction); humerus medially rotated (loss of teres major); forearm pronated (loss of biceps brachii); loss of sensation from lateral limb (loss of musculocutaneous nerve)

Question 11

Lower lesions of the Brachial Plexus are caused by excessive _____ of the arm, often from breech births or a child falling from a height.

Answer 11

abduction

Question 12

Lower lesions of the brachial plexus often affect the ulnar nerve, which supplies the small muscles of the hand. Avulsion of the C8 and T1 roots will cause:

Answer 12

Hyper extension of metacarpophalangeal joints (knuckles), flexion of interphalangeal joints (fingers)

Question 13

Lesion of what nerve causes Winged Scapula, impaired abduction of arm, and weakened triceps?

Answer 13

Long thoracic nerve - injured by blows or pressure on posterior triangle.

Question 14

Name the three passageways where brachial plexus nerves and subclavian vessels may be subject to compression via Thoracic Outlet syndrome.

Answer 14

Interscalene triangle;
Costoclavicular triangle;
Subcoracoid space.

Question 15

What two (spinal cord) nerve roots are most commonly involved in producing pain and paresthesia in thoracic outlet syndrome?

Answer 15

C8, T1, along ulnar nerve distribution

Question 16

The chief source of blood to the breast is found in what branch of the axillary artery?

Answer 16

Lateral thoracic artery

Question 17

A fixed scapula (via the serratus anterior muscle) is crucial in the origin/function of what arm muscle?

Answer 17

Triceps

Question 18

Which 4 muscles medially rotate the humerus?

Answer 18

Latissimus dorsi; anterior deltoid; teres major; subscapularis

Question 19

What artery and nerve pair is found in the quadrangular space?

Answer 19

Axillary nerve; posterior circumflex humeral artery

Question 20

What nerve and artery pair is endangered at the most common site of fractures?

Answer 20

The radial nerve and profunda brachii artery are found in the radial groove, which is in the triangular interval.

Question 21

Which vessels are found in the triangular space?

Answer 21

Circumflex scapular vessels

Question 22

Which muscles retract the scapula? What are their associated nerves?

Answer 22

Middle trapezius (CN11); rhomboid muscles(dorsal scapular nerve); levator scapulae (dorsal scapular nerve)

Question 23

What are the powerful lateral rotators of the humerus?

Answer 23

Teres minor, infraspinatus

Question 24

The axillary nerve may be damaged in a posterior dislocation of the shoulder. Such an injury may be diagnosed by demonstrating impaired skin sensation over the:

Answer 24

Lower half deltoid muscles

Question 25

The axillary nerve inner ages what two muscles?

Answer 25

Teres minor, deltoid

Question 26

Nerves important in carrying out pronation of the forearm are what nerve

Answer 26

Anterior interosseous branch of MEDIAN nerve

Question 27

The nerves of the brachial plexus are named according to their relationship with???

Answer 27

The middle segment of the axillary artery

Question 28

The axillary nerve contains all of the following nerve fibers EXCEPT:
A. GSA
B. GSE
C. GVA
D. Preganglionic SNS
E. Postganglionic SNS

Answer 28

Preganglionic SNS (GVE)

Question 29

A fractured clavicle may result in what 3 secondary problems?

Answer 29

Damage to subclavian vein (& pulmonary embolism)
Damage to subclavian artery (& brachial artery embolism)
Lesion of lower trunk of brachial plexus

Question 30

What nerve is vulnerable to damage by a lesion of the medial epicondyle?

Answer 30

Ulnar nerve

Question 31

Fracture of the surgical neck of the humerus will effect what nerve?

Answer 31

The axillary nerve

Question 32

What artery is injured in a fracture of the surgical neck of the humerus?

Answer 32

Posterior humeral circumflex artery

Question 33

Lateral rotators of the arm include what three muscles? (Which is not innervated by the axillary nerve?

Answer 33

Deltoid
Teres minor
Infraspinatus - innervated by the suprascapular nerve

Question 34

The median cubital vein lies superior to what artery?

Answer 34

Brachial artery

Question 35

What nerve is medial to the brachial artery in the cubital fossa?

Answer 35

Median nerve