14.4 receptors Flashcards
list the 2 features of sensory receptors.
1- specific to 1 type of stimulus
2- produces generator potential by transducing
what happens when a pacinian corpuscle is applied with pressure? (3)
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
what is deformed when a pacinian corpuscle is pressurised?
stretch-mediated Na+ channels
what are the 2 types of receptors in the eye?
rod & cone cells
how do receptors in the eye work as tranducers?
transduces light energy to electrical energy of nerve impulse
which receptor detects low intensity light?
rods
why are many rod cells connected to 1 bipolar cell? what are the advantages & disadvantages of it?
- threshold value could be reached more easily
- only 1 impulse is sent upon stimulation of many rod cells -> low visual acuity
where are rod cells located?
periphery of retina & absent at fovea
where are cone cells located?
concentrated at fovea & less at periphery
how does visual receptors detects stimulus in the eye?
iodopsin / rodopsin are broken doen by light & change is detected by chemoreceptors
why are there 3 types of iodopsin?
different wavelengths of light