receptors

Question 1

What is pacinian corpuscle receptor?

Answer 1

A mechanical pressure receptor in the skin

Question 2

What does the structure of pacinian corpuscle contain?

Answer 2

• lamellae
• 1st Node of Ranvier
• sensory neurone

Question 3

What occurs when the Pacinian corpuscle is stimulated?

Answer 3

• lamellae becomes deformed and presses on sensory neurone ending
• sensory neurone membrane stretches=stretch-mediated Na+ channels open
• Na+ diffuses into cell=generator potential
• if threshold reached action potential generated

Question 4

Explain how we see colour in rods and cone cells

Answer 4

cones-give info in colour (trichromatic vision i.e. red-sensitive,green,blue) different colours seen based off proportion 3 cones are stimulated
rod-one type of rod cell so stimulation gives monochromatic vision i.e. black and white

Question 5

explain visual acuity in rod and cone cells

Answer 5

it’s the sharpness of vision
rod cells-synpase with same bipolar cell so hard to determine direction light shone + lowest VA in peripheral vision light stimulates large breadths of retina
cone-synpases with one bipolar cell so brain can determine exact direction of light + highest VA at fovea which has more cone cells

Question 6

explain sensitivity to light in rod and cone cells

Answer 6

rod-more rod cells synapse with one bipolar cell so low level stimuli can trigger action potential in BC so can respond to low levels of light.
cone-require higher stimulus before they can cause bipolar cell to reach threshold.