L7 MS

Question 1

What is formed when ventral rami in certain areas of the spinal cord tend to join and divide in complex patterns?

Answer 1

Nerve plexus

Question 2

What are the five different sections of the brachial plexus?

Answer 2

Roots, Trunks, Divisions, Cords, Branches

Mnemonic: Reach To Drink Cold Beer

Question 3

What are the three trunk division of the brachial plexus?

Answer 3

Upper (C5, C6)
Middle (C7)
Lower (C8, T1)

Question 4

What are the two divisions of the brachial plexus? How does each trunk contribute to the two divisions?

Answer 4

Anterior division and Posterior division.
Each trunk contributes to the two divisions
Upper Middle Lower —> Anterior
Upper Middle Lower —> Posterior

Question 5

What are the three cords of the brachial plexus? What are they named in relation to?

Answer 5

Lateral, Medial, and Posterior

These three are named according to position relative to the axillary artery

Question 6

How many branches does each cord split into? What are they?

Answer 6

Two branches each.
Lateral splits into the musculocutaneous branch
Medial splits into ulnar branch
Both Lateral and Medial contribute to the median branch
The posterior cord splits into the Axillary and Radial nerves

Question 7

Which branch has contributions from two different cords?

Answer 7

Median nerve has contributions form the lateral and medial cords

Question 8

What are the five branches of the BP?

Answer 8

Musculocutaneous
Axillary
Median
Radius
Ulnar

Question 9

Which roots contribute to the musculocutaneous nerve?

Answer 9

C5, C6, C7

Question 10

How many total branches are contributed by the medial and lateral cords? What are they?

Answer 10

Three.
Musculocutaneous
Medial
Ulnar

Question 11

What are the two branches contributed by the posterior cord?

Answer 11

Axillary

Radial

Question 12

Which cords contribute one and a half branches each?

Answer 12

Lateral and medial

Question 13

C5, C6, C7 contribute to what branch of the BP?

Answer 13

Musculocutaneous

Question 14

C5 and C6 contribute to what branch of the BP?

Answer 14

Axillary

Question 15

Which branch receives contributions from all the roots of the BP?

Answer 15

Radial (some say Median too)

Question 16

Which roots contribute to the ulnar branch of the BP?

Answer 16

(C7), C8 and T1

Question 17

Which roots contribute to the Median branch of the BP?

Answer 17

(C5), C6, C7, C8, T1

Question 18

C8 and T1 cotribute to what branch of the BP?

Answer 18

Ulnar

Question 19

Which branch receives contributions from C5, C6, C7, and C8?

Answer 19

Radial (some say Median too)

Question 20

What muscles does the Axillary nerve innervate?

Answer 20

Deltoid, Teres minor, Superior lateral brachial cutaneous

Question 21

What muscles does the Musculocutaneous innervate?

Answer 21

Carocobrachialis, Biceps Brachii, Brachialis, Lateral antebrachial cutaneous

Question 22

What muscles does the radial innervate?

Answer 22

13 muscles of the posterior arm and forearm
Lateral brachial cutaneous
Posterior antebrachial cutaneous

Question 23

What muscles does the Median innervate?

Answer 23

Flexor muscles of the forearm and a few hand muscles.

Lateral cutaneous area of hand

Question 24

What muscles does the ulnar innervate?

Answer 24

Hand muscles,

Skin of hand

Question 25

What nerves come off of the roots of the BP? What do they innervate?

Answer 25

Dorsal scapular innervates: Levator scapulae, and both major and minor Rhomboids Long thoracic innervates: Serratus anterior

Question 26

What nerves come off of the trunks? What do they innervate?

Answer 26

Suprascapular and Nerve to Subclavius. Suprascapular: Supraspinatus, Infraspinatus muscles Nerve to Subclavius: Subclavisu muscle

Question 27

What nerves come off of the cords of the BP?

Answer 27

Medial/Lateral Pectoral Thoracodorsal Upper/Lower Subscapularis Medial Brachial/Antebrachial Cutaneous

Question 28

What nerves form the branches of the BP?

Answer 28

``` Musculocutaneous Axillary Median Radial Ulnar ```

Question 29

What muscles does the medial/lateral pectoral innervate?

Answer 29

``` Pectoralis minor (med/lat) Pectoralis major (only lat) ```

Question 30

What muscle does the thoracodorsal innervate?

Answer 30

Latissimus Dorsi

Question 31

The subscapularis is innervated by what two nerves?

Answer 31

Upper and lower subscapular nerve

Question 32

What muscles does the lower subscapular nerve innervate?

Answer 32

Subscapularis muscle and teres major

Question 33

T/F The Upper Subscapular nerve innervates the subscapularis and teres major muscles

Answer 33

FALSE. it only innervates the subscapularis. The lower subscapular, however, does innervate both of those muscles

Question 34

What muscles does the musculocutaneous nerve innervate?

Answer 34

Coracobrachialis, Biceps, brachialis

Question 35

What muscles does the axillary nerve innervate?

Answer 35

Deltoid and teres minor

Question 36

What muscles does the median nerve innervate?

Answer 36

Flexors of the forearm

Question 37

What muscles does the radial nerve innervate?

Answer 37

Extensors of forearm, Triceps, anconeus,

Question 38

What nerve innervates the muscles of the hand?

Answer 38

Ulnar