Pacinian corpuscle.

https://www.youtube.com/watch?v=7LSB3wtO1wc

What is a pacinian corpuscle

A sensory receptor, it detects pressure, they are found in the deep layers of the skin, e.g the fingertips and soles of feet have a high number of pacinian corpuscles.

In response to pressure, pacinian corpuscle produces a nervous impulse, this impulse is called a generator potential.

Why is pacinian corpuscle a transducer

It is converting mechanical energy (pressure ) into the energy of a nervous impulse.

Explain structure of pacinian corpuscle.

In centre, we find the end of the sensory neurone. This is surrounded by many layers of connective tissue, between each layer of connective tissue, there is a layer of gel.

What is found in pacinian corpuscle

Pacinian corpuscle has stretch mediated sodium channels. Normally these channels are too narrow for sodium ions to diffuse through

When pressure is applied, it causes shape of pacinian corpuscle to change, this shape change causes the membrane of neurone to stretch

When stretched, causes stretch mediated sodium channels to widen, and sodiumm ions can diffuse through the channels into the neurone, causes the interior of the neurone to become positively charged.

Neurone has been depolarised. Effect of this is called generator potential.

What generator potential do

Causes a wave of depolarisation to pass down the sensory neurone to the central nervous system.

This wave of depolarisation is called an action potential. The action potential is how a nerve impulse is transmitted.