5.1.3- Neuronal Communication Flashcards
what are sensory receptors?
specialised cells that detect stimuli
what are sensory receptors known as and why?
ENERGY TRANSDUCERS
they convert different forms of energy into electrical energy
what are the 4 types of sensory receptors and what is their stimulus?
1- Mechanoreceptor- pressure and movement
2-Chemoreceptors- chemicals
3-Thermoreceptors- heat
4- Photoreceptors- light
what is an example of a mechanoreceptor?
Pachinian Corpuscle, in the skin
what is an example of a chemoreceptor?
Olfactory receptor in the nose
what is an example of a thermoreceptor?
End-bulbs of Kraus, in the tongue
what is an example of a photoreceptor?
Cone cells in the eye
what is the function of a sensory neurone?
carry impulses from receptors to the CNS
what is the function of a relay neurone?
connect the sensory and motor neurone, present in the CNS
what is the function of a motor neurone?
carry impulses from CNS to effectors
when in resting potential, what is the neurone cell membrane described as?
polarised
what is resting potential?
the potential difference across the neurone cell mebrane while the neurone is at rest
what happens during resting potential of neurones?
-3 sodium ions are transported out
-2 potassium ions are transported in
-the sodium-potassium pump controls this
-the sodium ion channels are closed so that sodium cannot come back into the neurone, while the potassium ion channels remain open so they can move back out
-this leads to the inside being negative and the outside being positive, with a difference of around -70mV
what is action potential?
the depolarisation of the neurone cell membrane, so the inside is more positive than the outside, occurring when the cell is active
what happens during action potential of neurones?
-sodium ion channels open, and potassium ion channels close
-this causes a rush of sodium ions into the neurone, causing the flip of charge
-the change becomes around +40 mV