MSK - Brachial Plexus Flashcards Preview

ESA 2 > MSK - Brachial Plexus > Flashcards

Flashcards in MSK - Brachial Plexus Deck (27):
1

What is the Brachial Plexus?

Where does it originate from?

Where does it lead?

What is it made of?

It is a network of nerve fibres

Originates from anterior rami (divisions) of cervical vertebral nerves C5, C6, C7 and C8, and of the first thoracic vertebral nerve, T1

Runs from neck, through axilla and into the arm

2

The Brachial Plexus can be divided into how many parts?

Name each of these parts

5

Roots

Trunks

Divisions

Cords

Branches

3

Which rami of which spinal nerves form the root part of the Brachial Plexus?

Anterior Rami of spinal nerves C5, C6, C7, C8 and T1

4

How many nerve fibres make up the trunks?

3

5

What nerve fibres combine to give this number of trunks?

Name the three trunks and explain how they get their names

Superior Trunk - C5 and C6 roots combine

Middle Trunk - Just a continuation of C7

Inferior Trunk - Combination of C8 and T1

6

When are the trunks formed?

Just before they enter the axilla through the apex

7

How many divisions does each trunk make as it enters the Axilla?

2

8

What happens to each division?

One travels anteriorly and one travels posteriorly

9

How are the cords formed?

Recombination of the six Divisions into three nerve fibres

10

How are the Cords named?

By their position relative to the Brachial Artery

11

Name the three cords and what divisions they are formed by

Lateral Cord - Formed by:

  • Anterior division of superior trunk
  • Posterior division of middle trunk

Posterior Cord - Formed by:

  • Posterior division of superior trunk
  • Posterior division of middle trunk
  • Posterior division of inferior trunk

Medial Cord - Formed by:

  • Anterior division of inferior trunk

12

Name the five branches that go on to supply the upper limb

Musculocutaneous

Axillary

Median

Radial

Ulnar

13

What roots does the Musculocutaneous nerve contain nerve fibres from?

C5, C6, C7

14

What does the Musculocutaneous nerve innervate?

Brachialis, Biceps brachii and Corocobrachialis muscles

15

What are the sensory functions of the Musculocutaneous nerve?

Gives off the lateral cutaneous branch of the forearm, which innervates the lateral half of the anterior forearm, and a small lateral portion of the posterior forearm

16

What roots does the Axillary nerve contain nerve fibres from?

C5 and C6

17

What does the Axillary nerve innervate?

Deltoid, Teres minor and the Long head of the Triceps brachii

18

What are the sensory functions of the Axillary nerve?

Gives off the superior lateral cutaneous nerve of arm, which innervates the inferior region of the deltoid (“regimental badge area”)

19

What roots does the Median nerve contain nerve fibres from?

C6 – C8 and T1

20

What does the Median nerve innervate?

Most of the flexor muscles in the forearm, the thenar muscles, and the two lateral lumbrical muscles that move the index and middle fingers

21

What are the Sensory functions of the Median Nerve?

Gives off the palmar cutaneous branch, which innervates the lateral part of the palm, and the digital cutaneous branch, which innervates the lateral three and a half fingers on the anterior (palmar) surface of the hand.

22

What roots does the Radial nerve contain nerve fibres from?

C5-C8 and T1

23

What does the Radial nerve innervate?

Triceps brachii, and the Extensor muscles in the posterior compartment of the forearm.

24

What are the Sensory functions of the Radial Nerve?

Posterior aspect of the arm and forearm, and the posterior, lateral aspect of the hand

25

What roots does the Ulnar nerve contain nerve fibres from?

C8 and T1

26

What does the Ulnar nerve innervate?

Muscles of the hand (apart from the thenar muscles and two lateral lumbricals), flexor carpi ulnaris and medial half of flexor digitorum profundus

27

What are the Sensory functions of the Ulnar Nerve?

Anterior and posterior surfaces of the medial one and half fingers, and associated palm area