Sensory Receptors Flashcards
Where are sensory receptors located?
In the sensory organs like ears and eyes
What do sensory receptors do?
Convert the stimulus into a nerve impulse
What are the 4 types of sensory receptors?
Mechanoreceptor
Chemoreceptor
Thermoreceptor
Photoreceptor
Give an example of a mechanoreceptor
Pacinian corpuscle
Give an example of a chemoreceptor
Olfactory receptor
Give an example of a thermoreceptor
End bulbs of Krause
Give an example of a Photoreceptor
Cone cell
What is multiple sclerosis?
An autoimmune disease that affects nerves in the brain and spinal cord. When the myelinated sheath thins and breaks down.
What are myelinated neurones?
Neurones with axons covered in myelin sheath (many layers of plasma membranes)
How are the layers of myelin created?
Schwann cells grow around e axon many times and add layers of phospholipids each time.
What is the role of the myelin sheath?
Insulate the axon
Helps conduct electrical impulses at a faster speed
What are the two main features of sensory receptors?
They are specific to a certain type of stimulus.
They act as a transducer by converting stimuli into impulses
Explain step by step briefly how your body detects your finger has touched a pin?
1) Resting state- sodium ion channels are too narrow for sodium ions to pass through.
2) pressure applied changes the shape of the corpuscle, this causes the membrane surrounding the neurone to stretch and deform.
3) membrane stretches, sodium ion channels widen, sodium ions diffuse into the neurone.
4) influx of sodium ions changes the potential of the membrane.
5) The generator potential creates an action potential that passes along the axon of the sensory neurone
How are sensory receptors like transducers?
They convert stimuli into nervous impulses, called a generator potential.
What is the refractory period?
The period of time after an action potential when the axon cannot be excited again. The voltage gated sodium ion channels remain closed.
