The Brachial plexus Flashcards
What levels do the upper limbs arise?
C5-T1
Why are there convergences of fibres in the plexus?
Each muscle takes a nerve supply from more than one spinal cord (occurs at the trunks)
Why are there divergences of fibres in the plexus?
Each cord segment both supplies flexors and extensors (occurs at the divisions)
What do the anterior divisions supply?
Flexors
What do the posterior divisions supply?
Extensors
Why is there re-assortment of fibres in the brachial plexus?
To distribute to the compartments (occurs at cord level) to form terminal branches
What roots form the brachial plexus?
Anterior rami of spinal nerves C5-T1
What is Erb’s palsy?
Injuries to the upper brachial plexus (C5 and C6)
What is the common cause for Erb’s palsy?
Shoulder dystocia
-during birth (shoulder hangs on the mother’s pelvis)
How does Erb’s palsy present?
Waiter’s tip
- Adducted arm
- Medially rotated
- Extended elbow
- Pronation
What is Klumpke’s palsy?
Injuries to the lower brachial plexus (C8 and T1)
How does Klupke’s palsy present?
Claw hand deformity
