6.1.2 Receptors Flashcards
What is P
Lamallae of connective tissue
What is Q
Sensory neurone’s axon
What is R
Myelin Sheath
Describe how the pacinian corpusle triggers an action potential
- Stretch-mediated sodium ion channels are deformed by increased pressure
- So sodium ion channels open, and sodium ions diffuse in
- Depolarisation occurs, leading to a generator potential
- Greater pressure causes more sodium ion channels to open, and so more sodium ions to diffuse in
What is the pacinian corpusle are deformed by pressure
Stretch-mediated sodium ion channels
What cells to the fovea only contain
Cone cells
Why is the visual acuity of a cone cell high
Each cone cell is connected to a seperate neurone
What cells are not found in the fovea
Rod cells
When talking about rod and cone cells, what should be reffered to for each
- Colour
- Visual acuity
- Visual sensitivity
- Impulses
Visual acuity of rod cell and why
Low as many rods are connected to one neurone
How does an increase in pressure affect the pacinian corpusle
- More stretch-mediated sodium ion channels are deformed
- More sodium ion channels open
- More sodium ion channels diffuse in
- More depolarisation, so more generator potentials
Colour of rod cell
Cannot distinguish colour
Colour of cone cell
Three types, each sensitive to different wavelengths of light, so detect the colours red, green or blue
Visual acuity of cone cell
High as each cone is connected to a seperate neurone
Visual sensitivity of cone cell
Low, as pigment is not very sensitive to light
Visual sensitivity of rod cell
High, as pigment in rods very sensitive to light
How do rod cells trigger impulse
Spatial summation provides enough neurotransmitter to neurone to reach threshold level
How do cone cells trigger impulse
Each cone cell sends seperate impulse to the brain
