Sensory receptors

Question 1

What are the two main features of sensory receptors?

Answer 1

they are specific to a single type of stimulus and they act as a transducer

Question 2

What are the four main types of sensory receptors?

Answer 2

mechanoreceptors, chemoreceptors, thermoreceptors and photoreceptors

Question 3

What is the role of a receptor as a transducer?

Answer 3

they convert the stimulus into a generator potential

Question 4

What does a pacinian corpuscle detect and where are they most found?

Answer 4

they detect mechanical pressure and mostly found in fingers and soles of feet

Question 5

What is the name of the special type of sodium ion channel in the pacinian corpuscle membrane?

Answer 5

stretch mediated sodium ion channel

Question 6

How does a pacinian corpuscle convert pressure into an impulse?

Answer 6

in resting state, stretch mediated sodium ion channels are too narrow to allow sodium ions through. The neurone has a resting potential. When pressure is applied, membrane changes shape and sodium ion channels widen allowing sodium ions to diffuse in. Membrane becomes depolarised as p.d. increases this causes an action potential