Basic Neuroscience Flashcards
In terms of polarity, are neurons non-polarised, simple polarised or highly polarised?
Highly polarised
What are the two major cell types in the nervous system?
Neurons and glia
What is the primary role of glia?
To support neurons
What do oligodendrocytes and Schwann cells do?
Myelinate axons of neurons
Where are oligodendrocytes found?
CNS
Where do Schwann cells work?
PNS
What is grey matter?
Nerve cell bodies. Outside of the brain e.g. cortex and basal nuclei and inner part of the spinal cord
What is white matter?
Axons and myelin. Inner part of the brain and outer part of the spinal cord.
What are axons specialised for?
Transmission of information
What are dendrites specialised for?
Receipt of information
Can neurons reproduce or not?
They do NOT reproduce
What can nerve cells communicate with?
Other nerve cells, muscle and glands
What 2 things does the movement of charged ions across cell membranes depend on?
Diffusion (concentration gradient – ions want to move from high to low) and electricity (charged ions want to move to areas of opposing charge).
What is the cell voltage/membrane potential?
The difference in charge from the different ions outside and inside the cell.
What are the 3 ways that ions can move across the cell membrane?
Pumps, protein carriers and ion channels.
During the resting membrane potential, where is the most sodium, outside or inside the cell?
Outside the cell. Sodium is positive, at resting potential the inside of the cell is negatively charged.
Is the resting cell membrane polarised or depolarised?
Polarised
When stimulation causes an action potential, what happens to the resting cell membrane?
It becomes depolarised as sodium channels open causing sodium ions to move into the cell and the inside of the cell becomes more positive. Repolarisation happens when the sodium channels close and the potassium channels open. Potassium moves out of the cell and the membrane potential returns to being negative.
In order for an action potential to occur the stimulus has to…
Reach the threshold. If the stimulus doesn’t reach the threshold then no action potential occurs.
What is the role of myelin?
It insulates the axon so that the action potential and travel quickly without dissipating out of the cell.
The condition multiple sclerosis affects the myelin. How?
Myelin is attacked by the body’s own immune system so there is decreased conduction in axons.
During an action potential when it reaches the axon end of the neuron it has to change from electric signals to ——– to cross the synapse.
Chemical signals
When the neurotransmitter is released into the synaptic cleft they bind to receptors on the second neuron. What does this cause?
Ion channels are opened and sodium moves into the second neuron to start a new action potential.
Name 7 neurotransmitters
Acetylcholine, adrenaline, noradrenaline, serotonin, GABA, dopamine and glutamate.
Based on the direction of conducted impulses what do sensory neurons do?
Originate from the sensory receptors to the processor
Based on the direction of conducted impulses, what do motor neurons do?
Conduct signals that originated in the CNS
Where are interneurons?
Between sensory and motor neurons
