How Nerves Work 1 Flashcards
What is the general structure of a neurone?
- Soma
- Dendrites
- Initial segment
- Axon
- Axon terminal
Whats the resting membrane potential?
-70mV
Why is the membrane potential of the nerves not -90mV as that is the equilibrium for potassium?
The membrane is permeable to other ions
Define action potentials
- All or nothing
- Self propegating
How are action potentials fired?
Through threshold potential being reached be graded potentials
What are examples of graded potentials?
- Generator
- Post synaptic
- End plate
- Pacemaker
What is temporal summation of a graded potential?
When the same EPSP is stimulated multiple times, causing the graded potential to “add up” and depolarise the cell
What is spatial summation?
When two different EPSPs are stimulated that add up and result in depolarisation to threshold
What is thresholds value?
-55mV
What is the cell depolarised to after an action potential has been fired?
+40mV
How is the intensity of action potentials shown?
Frequency of signals
What are afferent nerves?
Sensory nerves
What are interneurones?
- In the spinal cord
- Decide how to respond to a stimulus
Efferent nerves?
Carry the signal to the effector
