explain
pain
section
3
page
60
The peripheral nerves
Get on your own nerves
M
ost people know about muscles and joints. You can see
and touch them. You often see pictures of them onmedical
clinic walls. Unfortunately, nerves are often forgotten.
There are hundreds of metres of peripheral nerves in your
body. The peripheral nerves connect the brain and spinal
cord to your tissues and thus to the outside world. This
makes them really important, especially if a nerve is
damaged or stops working properly. Leading neuroscientists
argue that peripheral nerve problems are farmore common
than clinicians believe.
94-96
One way to learn the key facts about nerves is to get on
your own nerves. Find the point of your elbow (olecranon)
and then find the bony point (medial epicondyle) a few
centimetres away from the olecranon towards your trunk.
The ulnar nerve travels right between the two points. If you
then go a few centimetres towards your wrist (checkMr
Lee) and rub your finger sideways you should roll over the
ulnar nerve. Notice that it is at least half as thick as a
pencil, and slippery too. There are tens of thousands of
transmitting fibres (neurones) in this nerve and they will
transmit impulses while youmove and stretch. If you run
your finger back and forth across the nerve youwill
probably feel some pins and needles in your little finger.
You have probably opened a fewmechanical sensors and
the nerve is reacting normally. Youmay feel it in the
fingers – this is because the brain thinks it is coming from
your fingers.
Look at the nerve image on the next page. Nerves are cords.
They are about 50% ligament, whichmakes them quite
strong, and about 50% neurones. Some of these neurones
inform the spinal cord and brain about activity of the
sensors and others drivemuscles and sweat glands.
ulnar nerve
olecranon
medial epicondyle
