The Brachial Plexus

Question 1

What forms the brachial plexus?

Answer 1

The anterior rami of the spinal nerves

Question 2

What are the different parts of the brachial plexus?

Answer 2

Roots, Trunks, Divsions, Cords and branches

Question 3

What are the trunks and where do these come from?

Answer 3

Superior trunk= a continuation of the C5 and C6 roots
Middle trunk= a continuation of the C7 roots
Inferior trunk= a combination of the C8 and T1 roots

Question 4

What are two types of divisions called?

Answer 4

Anterior and posterior divisions

Question 5

What forms the different cords of the brachial plexus?

Answer 5

Lateral cord if formed by the anterior division of the superior trunk and the anterior division of the middle trunk
Posterior cord is formed by the posterior division of the superior trunk, the posterior division of the middle trunk and the posterior division of the inferior trunk.
Medial cord is formed by the anterior division of the inferior trunk

Question 6

What are the Braches of the brachial plexus?

Answer 6

Musclocutanours nerve, the axillary nerve, the median nerve, the raidal nerve and the ulnar nerve

Question 7

What are the roots of the musclocutaneous nerve?

Answer 7

C5, C6, C7

Question 8

What are the roots of the axillary nerve?

Answer 8

Roots C5 and C6

Question 9

What are the roots of the median nerve?

Answer 9

C6-T1

Question 10

What are the roots of the radial nerve?

Answer 10

C5-C8 and T1

Question 11

What are the roots of the ulnar nerve?

Answer 11

C8 and T1

Question 12

What is the sensory distrubution of the musclocutaneous nerve?

Answer 12

Gives of the lateral cutaneous branch of the forearm, and the innervates the lateral half of the anterior forearm

Question 13

What is the sensory innervation of the axillary nerve?

Answer 13

The regimental badge area

Question 14

What are the sensory branches of the median nerve?

Answer 14

Gives of the palmar cutaneous, so the palm and the lateral 3.5 fingers of the forearm

Question 15

What are the sensory functions of the radial nerve?

Answer 15

Posterior aspect of the arm

Question 16

What are the senstory functions of the ulnar nerve?

Answer 16

Anterior and posterior surfaces of 1.5 fingers

Question 17

How would you identify the brachial plexus in a cadaver?

Answer 17

Look for the M shape, and this consists of the muscultanous, median and ulnar nerves and then work from there.

Question 18

What are the two other nerves that come of the roots of the brachial plexus?

Answer 18

The dorsal scapular nerve and the long thoraic nerve

Question 19

What are the nerves that come from the trunks of the brachial plexus?

Answer 19

The suprascpaular nerve, the nerve to subcalvius

Question 20

What are the extra nerves that come from the lateral cord of the brachial plexus?

Answer 20

The lateral pectroal nerve

Question 21

What are the extra nerves that come from the medial cord of the brachial plexus?

Answer 21

the medial pectroa nerve, the medial cutaneous nerve of the arm, and the medial axillay nerve

Question 22

What is Erbs Palsy?

Answer 22

An upper brachial plaexus injury, affecting the nerves from the C5 and C6 spinal roots

Question 23

What causes the development of a erbs plasy?

Answer 23

When there is an excessive increase in angle between the neck and the shoulder

Question 24

What are some of the nerves affected in Erbs palsy?

Answer 24

Musclocutaneous, axillary suprascapular and the nerve to the subcalvius

Question 25

What are some of the musces that may be paralysed in a Erbs Palsy?

Answer 25

Supraspinatus, infraspinatus, subclvaius biceps brachi, brachialus, corcobrachilias, deltoid and teres minor

Question 26

What are the motor functions which are lost in a Erbs palsy?

Answer 26

Abduction at the shoulder, lateral rotation of the arm, supination of the foreamt, and flexion at the shoulder

Question 27

What are some of the symptoms of Erbs Palsy

Answer 27

Loss of sensation down the lateral side of arm, affected limb hangs weekly, medially roated by the action of pectoralis maor, and the postion known as the waiters tip is characterisitc of Erbs palsy.

Question 28

What is Klumphke Palsy?

Answer 28

a lower brachila plexus injury, C8-T1

Question 29

What can cause the development of a klumpke palsy?

Answer 29

Results from a excessive abduction of the arm.

Question 30

What nerves are affected in a Klumpke palsy?

Answer 30

Nerves from a T1 root so the median and the ulnar nerves

Question 31

Which muscles loose function in Klumpke Palsy?

Answer 31

All small muscles of the hand but flexion is usally unaffected

Question 32

What sensory function is lost in Klupmke Palsy?

Answer 32

A loss in sensosry fucntion down the media side of arm

Question 33

How would a patient present with Klumpke palsy?

Answer 33

Metocarpophalengeal joints are hyperextended, and interphalengeal joints are flexed giving a clawed appearance