Neurons and synaptic Flashcards
(18 cards)
How can messages be sent in a neuron?
Can only be sent in one direction
What is the cell body?
Contains the nucleus
What are the dendrites?
Extend out of the cell body and sends electrical impulses to the cell body from other neurons
What is the axon?
An extension of the neuron and carry’s impulses away from the cell body
What is the myelin sheath?
To increase the speed at which the impulses spread
What are the nodes of Ranvier?
Breaks between o.2 and 2mm in the myelin sheath
What is the purpose of the nodes of Ranvier?
To speed up transmission
What is a terminal button?
At the end of the axon that can communicate with the next neuron in the chain across the synapse
Why can impulses only travel in one direction?
Neurotransmitters can only be released from pre synaptic sites and bind to post synaptic receptor sites
What does a sensory neuron look like? and what is its purpose?
It has long dendrites and short axons. It carry’s signals from sensory receptors to the spinal cord and brain
What does a relay neuron look like? and what is its purpose?
It has short dendrites and short axons. It connects the sensory neurons to the motor neurons or other relay neurons
What does a motor neuron look like? and what is its purpose?
It has short dendrites and long axons. It carries signals from the central nervous system to the effectors
How does a neurotransmitter cross a synapse?
By using chemicals which diffuse across the gap between the two neurons
What is summation?
The combination of excitatory and inhibitory neurotransmitters determining if action potential will be generated
What will happen if there are more excitatory neurotransmitters?
Action potential is more likely to fire
What is action potential?
When the neuron is activated by a stimulus and becomes positively charged inside for a short time
What is an inhibitory effect?
Neurotransmitters make the neuron more negatively charged, causing it to be less likely to fire (Example Serotonin)
What is an excitatory effect?
Neurotransmitters make the neuron more positively charged, causing it to be more likely to fire (Example Adrenalin)
