14.4 receptors

Question 1

list the 2 features of sensory receptors.

Answer 1

1- specific to 1 type of stimulus
2- produces generator potential by transducing

Question 2

what happens when a pacinian corpuscle is applied with pressure? (3)

Answer 2

1- pacinian corpuscle is deformed & membrane around is stretch
2- Na+ diffuses into membrane which is depolarised
3- generator potential produces action potential & is passed along neurone

Question 3

what is deformed when a pacinian corpuscle is pressurised?

Answer 3

stretch-mediated Na+ channels

Question 4

what are the 2 types of receptors in the eye?

Answer 4

rod & cone cells

Question 5

how do receptors in the eye work as tranducers?

Answer 5

transduces light energy to electrical energy of nerve impulse

Question 6

which receptor detects low intensity light?

Answer 6

rods

Question 7

why are many rod cells connected to 1 bipolar cell? what are the advantages & disadvantages of it?

Answer 7

• threshold value could be reached more easily
• only 1 impulse is sent upon stimulation of many rod cells -> low visual acuity

Question 8

where are rod cells located?

Answer 8

periphery of retina & absent at fovea

Question 9

where are cone cells located?

Answer 9

concentrated at fovea & less at periphery

Question 10

how does visual receptors detects stimulus in the eye?

Answer 10

iodopsin / rodopsin are broken doen by light & change is detected by chemoreceptors

Question 11

why are there 3 types of iodopsin?

Answer 11

different wavelengths of light