receptors Flashcards
what are the type of sodium ion channels on pacinian corpuscles
strech mediated sodium ion channels
what happens to the strech mediated sodium ion channels when pressure is applied to the skin
they open and causes an influx of sodium ions
what are pancian corpuscles
mechanoreceptors they detect mechanical stimulii and they are found in the skin
what do pancian corpuscles contain
a sensory nerve ending wrapped in layers of connective tissue called lamellae.
where a rod cells mainly found and how many types of them are there
mainly located in the peripheral parts of the retina
1 type so they give information in black and white
how many rod cells connect to one bipolar cell and how sensitive are they to light
they have a high sensitivity to light
and many rod cells join to one bipolar cell
what kind of visual acuity do rod cells have
low visual acuity
where are cone cells found
they are mainly located in the fovea
how many types of rod cells are there
3 types one for each wavelength of light so they give information in colour
how many cone cells join to one bipolar cell
one cone joins to one bipolar cell
what kind of sensitivity to light do cone cells have
low sensitivity to light
what kind of visual acuity do cone cells give
a high visual acuity
why do cone cells give high visual acuity
as cones are close together
one cone joins to one bipolar neurone
when light from two points hit two cones two A/Ps go to the brain
so distinguish between two points close together as two seperate points
why are rod cells sensitive to light
many rods join one bipolar neurone
so many weak generator potentials combine
to reach threshold and trigger an action potential
why are cones not sensitive to light
one cone joins to one bipolar neurone
so it takes more light to reach threshold
and trigger an action potential
why do rods have low visual acuity
many rods join to one bipolar neurone
means light from two points close together can’t be told apart
what are photoreceptors
the receptors in your eye that detect light
what is cardiac muscle
it is myogenic meaning it can contract and relax without nerve impulses/signals
what is the function of the sinoatrial node
sets rhythm of heartbeat by sending out regular waves of electrical activity to atrial walls
causing left and right to contract at the same time
what prevents the electrical activity passing directly from the atria to ventricles
band of non-conducting collagen tissue prevents electrical activity passing from atria to ventricles
what is the electrical activity transferred to instead of going directly from atria to ventricles
electrical activity goes from the sinoatrial node to the atrioventricular node
what is the function of the atrioventricular node
passing waves of electrical activity on to the bundles of his
slight delay before AVN reacts to make sure the atria are empty before ventricles contract
What is the bundle of his
group of muscle fibres responsible for conducting the waves of electrical activity between the ventricles and apex of the heart
what does the bundle of his split into it
finer muscle fibres in both ventricles called the purkyne tissue
