Lecture 4--brachial Plexus

Question 0

What is the saying for the brachial plexus

Answer 0

Robert Taylor Drinks Cold Beer.

Question 1

What do the dorsal rami supply?

Answer 1

Joints of the vertebral column, deep back muscles and the skin of the back. Everything else is ventral rami.

Question 2

Where are the ventral rami?

Answer 2

Between the anterior and middle scalene muscles. They are Supraclavicular meaning they are above the clavicle.

Question 3

Where are the trunks located?

Answer 3

Anterior surface of the middle scalene. They are Supraclavicular meaning they are above the clavicle.

Question 4

Where are the trunks located?

Answer 4

Posterior and inferior to the clavicle. They are infraclavicular.

Question 5

How are the cords named?

Answer 5

In relation to the axillary artery. The medial cord is lateral and the lateral cord is medial. It is infraclavicular.

Question 6

What are the components of the brachial plexus?

Answer 6

Rami, trunks, divisions, cords, branches

Question 7

___ runs posteriorly along the medial border of the scapula with its artery. It is motor to the levator and rhomboids.

Answer 7

Dorsal scapular nerve c4-c5

Question 8

___ descends posterior to the c8 and t1 ventral rami on the middle scalene and passes distally on the external surface of the serratus. It is motor to the serratus.

Answer 8

Long thoracic nerve c5-c7

Question 9

What nerves come off the branches of the brachial plexus

Answer 9

Dorsal scapular nerve and long thoracic nerve

Question 10

What nerves come off the trunks of the brachial plexus

Answer 10

Superior trunk: supra scapular nerve c4-c6. And nerve to subclavius c4-c6.

Question 11

___ goes posteriorly in the posterior triangle of the neck, through the suprascapular notch. It is motor to the infraspinatus and supraspinatus.

Answer 11

Suprascapular nerve c4-c6

Question 12

___ juts straight forward into the clavicle. Descends posterior to the clavicle and anterior to the brachial plexus and subclavian artery. Motor to the subclavius.

Answer 12

Nerve to subclavius.

Question 13

What nerves come off the divisions of the brachial plexus

Answer 13

NONE

Question 14

What nerves come off the cords of the brachial plexus

Answer 14

Lateral: lateral pectoral nerve, musculocutaneous nerve,
Posterior: upper subscapular nerve, thoracodorsal nerve, and lower subscapular nerve, axillary nerve, and radial nerve.
Median: medial pectoral, medial brachial cutaneous, medial antebrahisl cutaneous, median, and ulnar

Question 15

___ pierces the clavipectoral fascia to reach the deep surface of the pec major. It’s motor to the pec major. Goes into the deep surface of the pec major.

Answer 15

Lateral pectoral nerve

Question 16

____ diverges laterally, leaving the axilla by piercing the corachobrachialis.

Answer 16

Musculocutaneous nerve

Question 17

____ is motor to the anterior compartment of the arm and sensory to the lateral aspect of the arm (lateral antebrahisl cutaneous).

Answer 17

Musculocutaneous nerve

Question 18

____ passes posteriorly and enters the subscapularis. It is motor to the subscapularis

Answer 18

Upper subscapular nerve

Question 19

____ runs inferolaterally along the posterior axillary wall.

Answer 19

Thoracodorsal nerve

Question 20

____ passes inferolaterally deep to the subscapular artery and vein.

Answer 20

Lower subscapular nerve

Question 21

Motor to the subscapularis and teres major

Answer 21

Lower subscapular nerve

Question 22

Turns posterolaterally to pass the posterior aspect of the arm through the quadrangular space with the posterior circumflex humeral artery.

Answer 22

Axillary nerve

Question 23

Descends posteriorly to the axillary artery. Winds around the humerus with the profunda brachii.

Answer 23

Radial nerve

Question 24

Motor to the posterior compartment of the forearm and arm.

Answer 24

Radial nerve

Question 25

Sensory to the posterior and inferolateral aspects of the arm, posterior aspect of the forearm and dorsum of the hand lateral to a line bisecting the 4th digit from the dip and pip joints proximal

Answer 25

Radial nerve

Question 26

Passes between the axillary artery and vein and pierces the pec minor.

Answer 26

Medial pectoral nerve

Question 27

Runs along the medial side of the axillary vein. Joins often, with the intercostobrachial nerve on its way to the arm.

Answer 27

Medial brachial cutaneous nerve

Question 28

Sensory to the medial aspect of the arm

Answer 28

Medial brachial cutaneous nerve

Question 29

Runs between the axillary artery and vein

Answer 29

Medial antebrahial cutaneous nerve

Question 30

Sensory to the medial aspect of the forearm

Answer 30

Medial antebrahial cutaneous nerve

Question 31

Runs anterior, or lateral to, the axillary artery.

Answer 31

Median nerve

Question 32

Motor flexors of the forearm, promotors of the forearm, and thenar muscles.

Answer 32

Median nerve

Question 33

Runs between the axillary artery and vein.

Answer 33

Ulnar artery

Question 34

Motor to fcu, ulnar half of fdp, intrinsic muscles of the hand except the ones Innervates by the median nerve.

Answer 34

Ulnar nerve

Question 35

What would an upper brachial plexus injury look like in the clinic? (C5-c6)

Answer 35

Trouble with flexing the elbow. C5 is elbow flexion and musculocutaneous nerve supplies this. If just c5 you wouldn’t have complete loss but you would have difficulty with elbow flexion. Shoulder abduction would be difficult because the deltoid and the supraspinatus are supplied by the axillary and suprascapular nerves. Scapular retraction would be harder, c4-c5, with dorsal scapular nerve but you will still have the spinal accessory nerve, so this may not be as obvious. Shoulder medial rotation, but a much bigger loss of lateral rotation because of all the rotator cuff muscles. This can be called Erb’s palsy or Erb’s dusheine palsy. They show position of addiction, medially rotated, and extended.

Question 36

How would a lower brachial plexus injury present?

Answer 36

This is c8-t1. Usually a hyperabduction injury. Less common, but like falling and catching a tree. C8 is finger flexion and t1 is finger abduction. What you see when you have klumpie’s palsy is something called claw hand and this will result in an imbalance of flexors and extensors and a loss of intrinsic muscles of the hand.

Question 37

Wrist drop usually indicates what?

Answer 37

Radial nerve injury