Topic 3 - Biological Foundations Flashcards
What are neurons?
The building blocks of the brain.
What are the four types of neurons?
- Sensory neurons
- Interneurons
- Motor neurons
- Glial cells
What do sensory neurons do?
Help recode and transmit outside information to the spinal cord and brain.
What do interneurons do?
Communicate with other neurons.
What do motor neurons do?
Transmit messages from the central nervous system to the muscles.
What is the ratio of glial cells to neurons and what do they do?
10:1, these cells are important for waste disposal, axon protection, learning, and memory.
What is the basic journey through the neuron?
- Dendrite
- Nucleus
- Axon
- Axon terminal
- Synapse
What do dendrites do?
Absorb chemical stimulation from other neurons.
What does the nucleus do?
If there’s enough dendritic activity, it fires action potentials.
What does the axon do?
Conducts the electrical signal to axon terminals.
What does the axon terminal do?
Turn the electrical signal into a chemical squirt.
What is the synapse?
The jump the chemical has to make to be taken up by the next dendrite.
How do we observe action potentials?
Attaching microelectrodes to neurons.
Approximately how long does it take action potentials to fire?
5ms.
What are the steps for firing an action potential?
- Resting charge of -70mV
- Depolarization to positive charge
- Repolarization to negative charge
- Refractory period resulting in overcompensated negative charge
- Return to resting state in 5ms
What is the resting potential of the neuron?
The electrical charge inside the neuron when the neuron is at rest and receiving no stimulation.
When does an action potential become more likely?
When the negative resting potential becomes positive or when it becomes more negative because of hyperpolariztion.
What is another way in which information between neurons can be transmitted?
Through changes in chemical energy.
What are neurotransmitters?
Keys that unlock the gate for certain ions to jump through.
What do excitatory neurotransmitters do?
Allow positively charged ions into the postsynaptic cell, increasing the chance of an action potential.
What do inhibitory neurotransmitters do?
Allow negatively charged ions into the postsynaptic cell, decreasing the chance of an action potential.
What two ways do neurotransmitters reset?
- Terminal reuptake
- Chemical breakdown
What are some important neurotransmitters?
- Acetylcholine
- Norepinephrine
- Serotonin
- Dopamine
- GABA
What are some synthetic neurotransmitters?
- Botoz
- Prozac
How are differences in the sensory environment coded?
Changes in the rate of axon firing.
What is key about the autonomic nervous system?
It’s involuntary.
What does the parasympathetic nervous system do?
Maintains bodily function and inhibits the sympathetic.
When does the sympathetic nervous system activate?
When under pressure.
What does the somatic nervous system do?
Voluntary, controls sensory and motor nerves.
What are the three axes of the brain?
- Ventral (bottom) dorsal (top)
- Anterior (front) posterior (back)
- Medial (central) lateral (closer to ears)
What is the cerebral cortex?
The part of the brain that controls conscious function and psychology is most interested in.
What does the corpus callosum do?
Maintains connections between the brain’s hemispheres.