Sensory receptors (systems) Flashcards
Name 4 differnt types of neurones?
(Neuronal diversity)
- Anaxonic neurone
- Bipolar neurone
- Pseudounipolar neurone
- Multipolar neurone
Describe anaxonic neurones
Have more than two processes, but axons cannot be distinguished from dendrites
Describe bipolar neurones
Have two processes seperated by the cell body
Describe pseudounipolar neurones
Have a single enlongate process w the cell body situated to one side
Describe a multipolar neurone
Have more than 2 processes; there is a single axon & multiple dendrites
What are Aδ (delta) fibres like?
They are fast, myelinated & carry info about sharp, well loaclised pain
They conduct impulses at the rate of approx 20m/s
What are C-fibres like?
They are slower than Aδ (delta) fibres & unmyelinated and transmit dull aching pain i.e. diffusely localised
They conduct impulses at the rate of approx 1m/s
What are nocieptors?
Pain receptors
Are rapidly adapting - sensitive to noxious or painful stimuli
What are thermoreceptors?
Temperature receptors
What do chemireceptors detect?
Respond to water-soluble & lipid-soluble substances dissolved in body fluids
What sort of sensation do myelinated type A fibres carry?
Carry sensations of fast pain
What type of sensation do unmyelinated C fibres carry?
Carry sensations of slow pain
What do proprioreceptors do?
Monitor the positions of joints & muscles
Transmit sensory info from muscles, tendons & joints about the position of a body part - such as a limb in space
What do baroreceptors do?
Detect pressure changes
What do tactile receptors do?
Provide the sensations of touch, pressure & vibration
What are exteroceptors?
Are close to the body surface
What are the 2 types of exteroceptors?
- Teloreceptors
- Contact receptors
What are telorecpetors?
Include receptors that respond to distant stimuli (such as light or sound)
What are contact receptors?
Transmit tactile, pressure, pain or thermal stimuli
What are interoceptors?
Detect sensory info concerning the status of the body’s internal environment:
e.g. stretch, blood pressure, pH, oxygen or CO2 conc & osmolarity
What do mechanosensitive receptors?
Can detect pressure, membrane stretch & shear stress (e.g. blood flow)
What can temperature-sensitive receptors detect?
Can detect cold, cool, warmth & painfully hot
What are polymodal nociceptors?
On C-fibres which are sensitive to noxious stimuli that are mechanical, thermal or chemical in nature
What is the receptor that detects chillis?
TRPV1
