Session 2 - The Brachial Plexus Flashcards
What is the structure shown in the image?
The brachial plexus
What exactly is the brachial plexus?
A network of nerve fibres that run through the neck and axilla, into the arm.
What are the five divisions of the brachial plexus?
Read That Damn Cadaver Book
- Roots
- Trunk
- Divisions
- Cords
- Branches
What is A?
Roots of brachial plexus
What do 1-5 represent?
The anterior fibres of spinal nerves C5, C6, C7, C8, T1 respectively
What is a distinctive feature of the components of A?
What is B?
The trunks
What is 6, and what is it a combination of?
Superior trunk: A combination of C5 and C6 roots.
What is 7?
Middle trunk: A continuation of C7.
What is 8?
Inferior trunk: A combination of C8 and T1 roots.
When are the trunks formed?
just before they enter the axilla through the axillary inlet (or apex)
What is C?
The divisions
What are 9 and 10?
9 - Anterior divisons
10 - Posterior divisions
What do the divisions leave us with?
What is D?
The cords
What are the sections of D formed by, and what are they named relative to?
The cords are formed by recombination of the six divisions to three nerve fibres
They are named by their position relative to the brachial artery.
What is 11 and what is it formed by?
Lateral cord (lateral to the brachial artery): Formed by…
The anterior division of the superior trunk,
The anterior division of the middle trunk
What is 12?
Posterior cord (behind the brachial artery): Formed by….
The posterior division of the superior trunk
The posterior division of the middle trunk
The posterior division of the inferior trunk
What is 13?
Medial cord (medial to the brachial artery): Formed by
The anterior division of the inferior trunk.
What is 14?
Musculocutaneous Nerve
What are the roots of the Musculocutaneous Nerve?
What are its motor functions?
Roots: C5, C6, C7
Motor Functions: Innervates the brachialis, biceps brachii and corocobrachialis muscles
What is 15?
What are its roots?
Axillary Nerve
C5 and C6
What is the motor function of the axillary nerve?
Innervates the deltoid, teres minor and the long head of the triceps brachii
What is 16?
What are its roots?
Median nerve
Roots: C5 – C8 and T1
What is the motor function of the median nerve?
Innervates most of the flexor muscles in the forearm
What is 17?
What are its roots?
Radial Nerve
What is the motor function of the radial nerve?
What is 18?
What are its roots?
The ulnar nerve
Roots: C8 and T1
What is the motor function of the ulnar nerve?
Innervates the muscles of the hand
What can damage to the axillary nerve cause?
Loss of sensation in the regimental patch
