The nerves of the limbs

The terminal nerves of the brachial and lumbosacral plexuses, the muscles they control and what damage to them reveals.

The outline, topic by topic

Each topic is weighted the way the exam weighs it.

Musculocutaneous nerve: what is it?
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The nerve of the front compartment of the arm: biceps, brachialis, coracobrachialis.
Damage weakens elbow flexion.
After a shoulder dislocation, the patient can no longer raise the arm sideways and has lost feeling over the shoulder. Which nerve?
- The axillary nerve
- The radial nerve
- The median nerve
- The musculocutaneous nerve
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The axillary nerve
It winds round the neck of the humerus, just below the joint.
Axillary nerve: what is it?
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The nerve winding round the neck of the humerus, supplying deltoid and teres minor.
At risk in shoulder dislocations.
Why does damage to a nerve cause both weakness and a numb area?
- Muscles feel the skin
- Skin controls the muscles
- A limb nerve is mixed: it carries motor and sensory fibres
- Only the spinal cord is affected
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A limb nerve is mixed: it carries motor and sensory fibres
The numb area helps identify the damaged nerve.