receptors

Question 1

give 3 stimuli that are detected by mammals

Answer 1

• pressure
• temperature
• light
• chemicals
• sound

Question 2

what is the difference between sensory reception and sensory perception

Answer 2

sensory reception = detection of stimuli by receptors

perception = CNS making sense/processing these stimuli

Question 3

define receptor

Answer 3

a cell adapted to detecting change within the environment

Question 4

receptors are highly specific

what does this mean?

Answer 4

they only respond to one type of stimulus

Question 5

receptor cells are transducers

what does this mean?

Answer 5

they convert the energy of the stimulus into an electrical impulse (called a generator potential THIS ONLY OCCURS IF THE STIMULUS IS LARGE ENOUGH)

E.G: light receptors of the retina in an eye

Question 6

what stimulus does the Pacinian Corpuscle detect

Answer 6

pressure
vibrations

Question 7

where are Pacinian Corpuscle’s located

Answer 7

fingers, soles of feet, external genitalia (deep in the skin)

in joints and tendons - provide feedback in the direction of movement

also found in bladder and rectum

Question 8

what happens when a pressure stimulus is applied to the Pacinian Corpuscle

Answer 8

1. pressure applied causes lamellae to deform
2. pressure causes stretch mediated sodium (Na+) channels to change shape
   enables Na+ to diffuse into the cell
3. influx of Na+ changes the potential difference and causes a generator potential
4. if stimulus is strong enough, more Na+ move into cell and threshold level is reached and an action potential is generated