How Nerves Work 3 Flashcards
Define a graded potential.
Decide when an action potential is going to be fired.
Define an action potential.
Sent when a cell is depolarised to threshold.
Define signal transduction.
When a physical stimulus is made into an electrical response.
What are sensory receptors often called?
Generator potentials.
How do signals move around the body?
Between synapses by the removal of a chemical neurotransmitter from the presynaptic neuron and binds to a receptor of the postsynaptic neuron (graded).
What are 4 examples of graded potentials?
Generator - sensory
Postsynaptic - synapses
Endplate - NMJ
Pacemaker - pacemaker tissues
Define decremental.
Depolarisation occurs in cell, axon is activated and charge moves but some leaks out. Potentials decay very quickly.
Define graded.
Can signal stimulus intensity in their amplitude.
Define de/hyperpolarisation.
Can excite (de) or inhibit (hyper) a cell as they need to reach firing threshold for action potentials to be sent.
What is the best way to depolarise a cell?
Open sodium channels.
What is the best way to hyperpolarise a cell?
Open potassium or chlorine channels.
Why is summate important?
It is important in synaptic integration to look at all the activity and see if the threshold has been reached.
Define synaptic integration.
Dendrites which are closer to the axon hillock have a greater energy as they are closer to where the action potential is decided to be fixed.
Individual dendrites can’t reach thresholds by themselves to signals have to be added together or repeatedly send the same signal.
What are inhibitory dendrite signals?
Can cause hyperpolarisation and bind to excited channels to stop the cell reaching threshold.
