topic 6 receptors Flashcards
how are receptors specific?
they only detect one particular stimulus
what are the two types of receptors?
cells or proteins on cell surface membranes
what happens when a receptor is in its resting state?
difference in charge inside and outside the cell, which is generated by ion pumps and ion channels= potential difference
what is resting potential?
the potential difference when the cell is at rest
how is the potential difference of a receptor altered?
stimulus is detected
cell membrane is excited and becomes more permeable
allows more ions to move in/out of the cell
what is the generator potential?
change in potential difference due to a stimulus
how is a bigger generator potential produced?
bigger stimulus
what happens if the generator potential is big enough?
triggers an action potential if the threshold level is reached
what is an action potential?
electrical impulse along a neuron
how is the strength of a stimulus measured by?
the frequency of action potentials
what is a Pacinian Corpuscle?
mechanoreceptor that detects pressure
what is the structure of a Pacinian Corpuscle?
sensory nerve ending wrapped in layers of connective tissue known as lamellae
how do Pacinian Corpuscles trigger action potentials?
when stimulated by pressure, lamellae deform and press on the sensory nerve ending
stretch mediated sodium ion channels open and Na+ diffuses into the cell
generator potential above the threshold is created
