Sensory receptors

Question 1

What is the function of sensory receptors?

Answer 1

detect stimuli

these are often located in sense organs

Question 2

How do snesory receptors work?

Answer 2

convert the stimulus they detect into a nerve impulse

the information is then passed through the nervous system and on into the central nervous system, usually the brain

Question 3

What is the function of the brain?

Answer 3

coordinate the required response and sends an impulse to an effector, normally a muscle or gland, to result in a desired response

Question 4

What are the 2 main features of a sensory receptor?

Answer 4

they are specific to a single type of stimulus

they act as a transducer - they convert a stimulus into a nerve impulse

Question 5

Which receptors detect mechanical pressure, and what is their function?

Answer 5

Pacinian corpuscle

specific snesory receptors that detect mechanical pressure

they are located deep within your skin and are most abundant in the fingers and the solves of your feet

they are also found within joints,e ngabling you to know which joints are changing direction

Question 6

What is the structure of the Pacinian corpuscle?

Answer 6

sensory neurone is found within the centre of the corpuscle

surrounded by layers of connective tissue, separated by a layer of gel

contains sodium ion channels

Question 7

What is the name and function of the the special type of sodium channel in the Pacinian corpuscle?

Answer 7

stretch-mediated sodium channel

when these channels change shape, e.g. when they stretch, their permeability the sodium changes

Question 8

What is the resting state of a sodium ion channel?

Answer 8

1. in resting state, the stretch-mediated sodium ion channels in the sensory neurone’s membrane are too narrow to allow sodium ions to pass through them. The neurone of the Pacinian corpuscle has a resting potential

Question 9

How does the Paciniam corpuscle convert mechnaical pressure into a nervous impulse?

Answer 9

1. when pressure is applied, the corpuscle changes shape, this causes the membrane surrounding the neurone to stretch
2. when the membrane stretches, sodium ion channels present widen, sodium ions can diffuse into the neurone
3. the influx of positive sodium ions changes the potential of the membrane - it becomes depolarised, this results in a generator potential
4. in turn, the generator potential creases an action potential that passes along the sensory neurone