8-Lecture: Brachial Plexus

Question 1

Roots: ventral rami from?

• Dorsal Scapular n: ?
• Long thoracic n: ?

Answer 1

Roots: ventral rami from C5-T1

• Dorsal Scapular n: C5 root
• Long thoracic n: C5-C7 roots

Question 2

Trunks: the 5 ventral rami coalesce into 3 trunks

• Upper trunk: roots?
  
  • -[blank] n: ?
  • -{blank] n: ?
• Middle trunk: ?
• Lower trunk: ?

Answer 2

• Upper trunk: C5-C6
  
  • -Suprascapular n: C5-C6
  • -Subclavian n: C5-C6
  • Middle trunk: C7
  • Lower trunk: C8-T1

Question 3

Each trunk splits into Anterior and Posterior Divisions

Answer 3

-

Question 4

Cords: named by their relation to axillary artery;

• Lateral cord: roots?
  
  • -[blank] n: ?
• Posterior Cord: ?
  
  • -[blank] n: ?
  • -[blank] n: ?
  • -[blank] n: ?
• Medial Cord:?
  
  • -[blank] n: ?
  • -[blank]?

Answer 4

• Lateral cord: C5-C7
  
  • -Lateral Pectoral n: C5-C7
  • Posterior Cord: C5-C8
    
    • -Upper subscapular n: C5
    • -Thoracodorsal n: C6-C8
    • -Lower sub scapular n: C6
  • Medial Cord: C8-T1
    
    • -Medial pectoral n: C8-T1
    • -Medial cutaneous nn of the arm and forearm: C8-T1

Question 5

Axillary nerve: Identify, name both spinal root and what cord(s) it stems from.

Answer 5

C5-C6. From posterior cord.

Question 6

Radial nerve: Identify, name both spinal root and what cord(s) it stems from.

Answer 6

C5-C8. From posterior cord.

Question 7

Musculocutaneous nerve: Identify, name both spinal root and what cord(s) it stems from.

Answer 7

C5-C7. Continuation of lateral cord.

Question 8

Median nerve: Identify, name both spinal root and what cord(s) it stems from.

Answer 8

C6-T11. From both lateral and medial cords (Center of “M”)

Question 9

Ulnar nerve: Identify, name both spinal root and what cord(s)it stems from.

Answer 9

C8-T11. Continuation of medial cord.

Question 10

Cutaneous innervation: Identify the Superior lateral cutaneous nerve of the arm. Name the root and peripheral nerve this stems from.

Answer 10

C5-C6. From axillary nerve.

Question 11

Cutaneous innervation: Inferior lateral cutaneous nerve of the arm. Name the root and peripheral nerve this stems from.

Answer 11

C5-C6. From radial nerve.

Question 12

Cutaneous innervation: Posterior cutaneous nerve of arm/forearm. Name the root and peripheral nerve this stems from.

Answer 12

C5-C8. From radial nerve.

Question 13

Cutaneous innervation: Superficial radial branch on dorsum and thenar area of hand. Name the root and peripheral nerve this stems from.

Answer 13

C6-C8. From radial nerve.

Question 14

Cutaneous innervation: Lateral cutaneous nerve of forearm. Name the root and peripheral nerve this stems from.

Answer 14

C6-C7. From musculocutaneous nerve.

Question 15

Cutaneous innervation: Cutaneous median nerve along palm (thenar side) and back of first 3 digits. Name the root and peripheral nerve this stems from.

Answer 15

C6-C8. From median nerve.

Question 16

Cutaneous innervation: medial cutaneous nerve of forearm. Name the root and peripheral nerve this stems from.

Answer 16

C8-T1. From ulnar nerve.

Question 17

Cutaneous innervation: dorsal branch of ulnar nerve-hypothenar area of hand. Name the root and peripheral nerve this stems from.

Answer 17

C8-T1. From ulnar nerve.