Brachial Plexus Part 1

Question 1

Which anterior primary rami form the brachial plexus in order to supply the upper extremities?

Answer 1

C5-T1 (may also receive some fibers from C4 and/or T2)

Question 2

Which rib does the brachial plexus travel across to reach the axilla?

Answer 2

rib 1

Question 3

What do roots combine to form?

Answer 3

trunks

Question 4

What do trunks divide into?

Answer 4

divisions

Question 5

What do divisions form?

Answer 5

cords

Question 6

What do cords divide into?

Answer 6

terminal nerves

Question 7

T/F: Each root of the brachial plexus receives a white ramus communicans from the sympathetic trunk.

Answer 7

False; should say gray ramus communicans

Question 8

Which scalene muscles do the roots of the brachial plexus pass between going into the posterior triangle?

Answer 8

anterior and medial scalene

Question 9

How do the roots of the brachial plexus pass the subclavian artery?

Answer 9

posterior and superior

Question 10

Which roots combine to form the superior trunk? middle trunk? inferior trunk?

Answer 10

C5 and C6;
C7;
C8 and T1

Question 11

What structure do the trunks of the brachial plexus pass over to get into the axilla?

Answer 11

rib 1

Question 12

What does each trunk of the brachial plexus split into?

Answer 12

anterior and posterior divisions

Question 13

T/F: anterior divisions of the brachial plexus will supply the anterior compartments while the posterior divisions will supply the posterior compartments of the arm and forearm.

Answer 13

True

Question 14

Cords of the brachial plexus are named for their relationship to what structure?

Answer 14

axillary artery

Question 15

What is the lateral cord of the brachial plexus formed by?

Answer 15

anterior divisions of the superior and middle trunks

Question 16

T/F: the lateral cord contains fibers from C4, C5, and C6.

Answer 16

False; should say C5-C7

Question 17

Which cord of the brachial plexus lies lateral to the second part of the axillary artery?

Answer 17

lateral cord

Question 18

Which cord of the brachial plexus is formed by the anterior division of the inferior trunk?

Answer 18

medial cord

Question 19

T/F: the medial cord contains fibers from C7, C8 and T1.

Answer 19

False; just C8 and T1 typically

Question 20

What cord lies medial to the second part of the axillary artery?

Answer 20

medial cord

Question 21

Which cord of the brachial plexus is formed by all three trunks?

Answer 21

posterior cord

Question 22

What roots cord levels supply fibers to the posterior cord?

Answer 22

C5-T1

Question 23

Which cord lies posterior to the second part of the axillary artery?

Answer 23

posterior cord

Question 24

What two nerves are formed from the roots of the brachial plexus?

Answer 24

dorsal scapular nerve and long thoraic nerve

Question 25

What nerve is formed from the fibers from C5 only?

Answer 25

dorsal scapular nerve

Question 26

What muscles are supplied by the dorsal scapular nerve?

Answer 26

levator scapula, rhomboid minor, and rhomboid major

Question 27

What muscle is supplied by the dorsal scapular nerve and also receives fibers from C3 and C4?

Answer 27

levator scapula

Question 28

What roots from the long thoracic nerve? What muscle is supplied?

Answer 28

C5-C7;

serratus anterior

Question 29

What do all of the muscles supplied by the dorsal scapular nerve and the long thoracic nerve have in common?

Answer 29

all attach to medial border of scapula

Question 30

What two nerves branch off of the superior trunk of the brachial plexus?

Answer 30

suprascapular nerve and nerve to the subclavius

Question 31

What cord levels contribute fibers to the suprascapular nerve?

Answer 31

C5 and C6

Question 32

What muscles are supplied by the suprascapular nerve?

Answer 32

supraspinatus and infraspinatus

Question 33

What nerve supplies the subclavius and what cord levels contribute fibers?

Answer 33

nerve to subclavius (C5 and C6)