Receptors

Question 1

what is the pacinian corpuscle?

Answer 1

receptors that responds to changes in pressure and vibrations
- they are found in the skin

Question 2

what is the structure of the pacinian corpuscle?

Answer 2

• lamellae surrounding the sensory nerve endings
• the sensory neurone

Question 3

what is the process of the pacinian corpuscle?

Answer 3

• increase in pressure causes the lamellae is deformed and presses on the sensory nerve ending
• this causes the sensory neuron’s cell membrane to stretch deforming the stretch mediated sodium ion channels
• the channels open and sodium ions diffuse into the neurone, and a generator potential is established due to depolarisation
• if the generator potential reaches threshold, the action potential will be triggered

Question 4

what are the receptors in the eye called?

Answer 4

• photoreceptors, receptors in the eye that detect light

Question 5

what controls the amount of light that enters the eye?

Answer 5

• controlled by muscles of iris

Question 6

where are photoreceptor cells?

Answer 6

• located in the retina
• fovea of retina contains most of the photoreceptors

Question 7

what happens to nerve impulses from photoreceptors cells?

Answer 7

• nerve impulses from photoreceptor cells are carried from retina to brain by the optic nerve
• where the optic nerve leaves the eye is called the blind spot

Question 8

what are rod cells sensitivity?

Answer 8

• very sensitive to light(work well in dim light)
• many rod cells join one bipolar neurone, so many weak generator potentials combine to reach threshold and trigger action potential

Question 9

what are cone cells sensitivity?

Answer 9

• less sensitive to light(work well in bright light)
• one cone joins one bipolar neurone, so takes more light to reach threshold and trigger an action potential

Question 10

what is visual acuity?

Answer 10

ability to tell apart points that are closer together

Question 11

what is the visual acuity of rod cells?

Answer 11

• low visual acuity = many rods join to the same bipolar neurone

Question 12

what is the visual acuity of cone cells?

Answer 12

• high visual acuity = cone cells are closer together and one cone cell joins one bipolar neurone
• two action potentials go to the brain

Question 13

what colour do rod cells give?

Answer 13

• black and white information

Question 14

what colour do cone cells give?

Answer 14

• gives information in colour

Question 15

what are the three types of cone cells?

Answer 15

• red, green and blue sensitive

Question 16

what pigment is in the rod cells?

Answer 16

rhodopsin

Question 17

what pigment is in the cone cells?

Answer 17

iodopsin