Receptors and control of heart rate Flashcards
Receptors definition
-specialised cells which detect a specific stimulus
-convert one form of energy into a generator protein
what is the pacinian corpuscle
-pressure receptor
-found mainly deep in the skin
also located in joints, tendons and ligaments
-made up of many layers called lamellae which surround the ending of a single sensory
how does the pacinian corpuscle work?
- increased pressure deforms
- changes the stretched mediated Na+ channels
- Na+ channel proteins open and Na+ diffuse in
- Depolarisation leads to a generator potential
types of receptor cells
cones
rods
rods information
-evenly distributed throughout the macula
-sensitive to all wavelengths of light
-high visual sensitivity to low levels of light intensity
-low visual acuity so image is unclear
-retinal convergence due to several rods sharing a single Bipolar neuron
cones information
-densely packed in the fovea
-each cone detects a specific wavelength of light
-iodopsin is less sensitive than rhodopsin so requires higher light intensity of photons
-high visual acuity giving sharp image
-this is because each cone cell connected with a single bipolar neuron
-cones send separate impulses to brain
how many rodes link to one neuron
3
how many cones link to one neurone
1
pigment in a rode
rhodopsin
pigment in a cone
iodopsin
how is a generator potential created
photons cause pigment to break down
altering the chemical structure
leads to a production of generator potential
rode cells properties
rod shaped
greater in number
poor visual acuity
sensitive to low intensity light
one type only
cone cells properties
cone shaped
lower in number
concentrated in fovea
good visual acuity
not sensitive to low intensity light
3 types
what type of summation do rods use
retinal convergence
what type of summation do cones use
temporal summation
