Introduction to Neurones Flashcards
What is the function of dendrites?
To receive inputs from other neurones and convey them to the cell body
What does the cell body do?
Integrate incoming signals that are conducted passively to the axon hillock
Why is an action potential most likely generated at the axon hillock?
As it contains the highest percentage of sodium channels
An axon mediates the transport of materials between what?
Soma and presynaptic terminal
What is a synapse?
The point of chemical communication between neurones
What are the types of neurones?
Unipolar
Pseudounipolar
Bipolar
Multipolar
Give an example of a unipolar neurone
Peripheral autonomic
Give an example of a pseudounipolar neurone
Dorsal root ganglion
Give an example of a multipolar neurone
Lower motor
What causes the upstroke of action potential in neurones?
Opening of voltage activated sodium channels
Once action potential is reached, what causes repolarisation?
Opening of potassium channels
What is the significance of a ‘leaky’ nerve cell membrane?
Passive signals do not spread far from site of origin
What ratio is used to calculate the distance which current spreads?
Membrane resistance/axoplasm resistance (referred to as lambda)
If lambda is increased will the action potential move along the axon faster or slower?
Faster
What substance is used to increase membrane resistance?
Myelin
