The term carpal tunnel is also used quite commonly to
refer to carpal tunnel syndrome. It is a condition where the median
nerve is pinched within the tunnel and causes pain. It is also
experienced in the numbness of the wrist or hand, once thought to be a
result of repetitive motion such as painting or typing. This is a
painful condition by continuous flexing or stressing over a lengthy
period of time which is caused by pressure on the median nerve that
carries nervous impulses back and forth between the hand and the spinal
cord.
Carpal tunnel is a fibro- osseous tunnel
on the palmar surface of the carpal bones. It transmits a number of
tendons and the median nerve from the forearm into the hand. Surface
markings are proximally the distal wrist crease or distally the hook of
the hamate bone.
Both base and walls of the carpal tunnel are a
concave bony channel that is formed by the carpal bones. It is the
flexor retinaculum or transverse carpal ligament that forms the roof of
the carpal tunnel. It attaches to the scaphoid tubercle and ridge of the
trapezium laterally, to the pisiform and hook the hamate medially.
The
recurrent thenar branch of the median nerve, the motor branch to the
thenar eminence, leaves the median nerve in or beyond the carpal tunnel.
It curves back over the flexor retinaculum to reach the thenar eminence.
If the incision over the calpar tunnel is made to far laterally, it is
dangerous making surgery.
The carpal tunnel transmits to only one
nerve, the median, and nine tendons. They are the following: flexor
digitorum superficialis which contributes to the four tendons that
insert on the middle phalanx; flexor digitorum profundus which
contributes to the four tendons that insert on the distal phalanx;
flexor pollicis longus; palmaris longus which is a tendon merging with
palmar aponeurosis; flexor retinaculum; flexor digitorum superficialis;
flexor pollicis longus; flexor digitorum profundus and skin.
Therefore,
the carpal tunnel is important because the median nerve can be
compressed in cases such as what was mentioned above, carpal tunnel
syndrome, wrist dislocations (result of this is that you cannot entirely
move your fingers and hands) and bone fractures (it is a minor injury in
which the fragments remain not in proper alignment so there is a need
for surgical treatments before it can be back to its normalcy).
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