Brachial Plexus And Anterior Arm

Question 1

What is the brachial plexus?

Answer 1

A network of nerves that lie within the arm
Supply motor innervation to muscle of shoulder, arm, forearm and hand Sensation
Sensory information to the bones, skin, muscle and connective tissue

Question 2

What are the roots of the brachial plexus?

Answer 2

C5,C6,C7,C8,T1

Question 3

Why is there a C8 in the roots of brachial plexus?

Answer 3

The nerves from C1 exist above the first cervical vertebrae, while the remaining cervical nerves exit below the cervical vertebrae. So C8 exists below C7 above T1

Question 4

What trunk is formed by c5 and c6?

Answer 4

Superior

Question 5

What trunk is form by C7?

Answer 5

Middle

Question 6

What trunk is formed by c8 and t1?

Answer 6

Inferior

Question 7

What do the anterior divisions of the middle and superior trunks join to form?

Answer 7

Lateral cord

Question 8

What do all the posterior divisions join to form?

Answer 8

The posterior cord

Question 9

What does the anterior divisions of the interior trunk form?

Answer 9

Medial cord

Question 10

What cord gives use to biggest nerves?

Answer 10

Posteiror - as all posterior divisions join

Question 11

What nerve does the lateral cord give rise to?

Answer 11

Musculutaneous nerve

Question 12

What nerves does the posterior cord give rise to?

Answer 12

Axillary and radial nerves

Question 13

What nerve does the medial cord give rise to?

Answer 13

Ulnar

Question 14

The lateral and medial cord Join together to form what?

Answer 14

Median nerve

Question 15

The lateral and medial cord Join together to form what?

Answer 15

Median nerve

Question 16

What is the role of the medial nerve?

Answer 16

Innervates flexors of the wrist and finger and gives sensation to lateral area of the hand

Question 17

What is the role of the ulnar nerve?

Answer 17

Innervates mainly small muscles of hand and gives sensation to medial area of the hand

Question 18

What does the musculocutaneous nerve do?
What does it give rise to?

Answer 18

Gives innervation to anterior compartment of the arm, branches directly in biceps brachii, gives rise to lateral cutaneous nerves

Question 19

What is the role of the radial nerve?

Answer 19

Innervates extensors of wrist and hand and gives sensation to posterior arm, forearm and hand.

Question 20

What is the role of the axillary nerve?

Answer 20

Muscles- deltoid and tere major
Gives sensation to skin over the deltoid
Passes posteriorly

Question 21

What is the role of the long thoracic nerve?

Answer 21

Passes anteriorly along anterior chest wall to supply motor innervation to the serratus anterior- branch from C5, C6,C7

Question 22

What are the muscles of the anterior arm?

Answer 22

Biceps brachii, brachialis, coracobrachialis

Question 23

What is the origin, insertion and innervation of the biceps brachii?
What are the actions?

Answer 23

Made up of two heads
Long head- origin coracoid process of scapula
Short head- origin from supraglenoid tubercle. Passes through the intertubercular groove
Insert at radial tuberosity- which attaches through bicipital aponeurosis
Innervated: Musculutaneous nerve
Actions: supinates the forearm- flexion when foearm is supinated

Question 24

What is the origin, insertion, innervation and actions of brachialis?

Answer 24

Origin on distal half of anterior aspect of humerus and adjacent parts of inter muscular septa
Lies beneath the biceps
Flattened dorsoventral LH and converges to form a tendon that attached to the tuberosity of the ulna
Action
* Foearm flexion
* Innervated by musculacutanoeus nerve
* Small lateral portion is Innervated by radial nerve

Question 25

What is the origin, insertion, innervation and actions of the coracobrachialis?

Answer 25

Origin- coracoid process of scapula, to medial side of midshat of humerus -Innervated by musculcutaneous nerve Inserts
Tends to merg with short head o biceps brachii
Actions:
Arm flexion and addiction

Question 26

What smaller branches arise from the C5?

Answer 26

Contributions to phrenic nerve and dorsal scapular nerve

Question 27

What are the smaller nerves of the superior trunk?

Answer 27

Suprascapular nerve, nerve to subclavius

Question 28

What are the smaller branches of the lateral cord?

Answer 28

Lateral pectoral nerves

Question 29

What are the smaller branches of the posterior cords?

Answer 29

Superior subscapular nerve
Thoracodorsal nerve
Inferiorly subscapular nerve

Question 30

What are the small branches rod the medial cord?

Answer 30

Medial pectoral nerve, medial cutaneous nerve of arm, medial cutaneous nerve of the forearm

Question 31

What does the dorsal scapula nerve do

Answer 31

provides motor innervation to the rhomboid major and minor

Question 32

What is the role of the long thoracic nerve

Answer 32

motor to serratus anterior muscle

Question 33

What does the medial cutaneous nerve of the arm supply

Answer 33

The medial distal 1/3 of the arm, sensory innervation

Question 34

What does the superior subscapular nerve supply

Answer 34

motor control to the subscapularis

Question 35

What does the thoracodorsal nerve supply

Answer 35

motor innervation to the latissimus doris muscle

Question 36

What does the inferior subscapular nerve supply

Answer 36

motor innervation to teres major and subscapularis

Question 37

What nerve does the musculocutaneous nerve become as it enters the forearm

Answer 37

the lateral cutaneous nerve of the forearm

Question 38

Between which two muscles does the brachial plexus arise

Answer 38

the anterior scalene and middle scalene