nervous system Flashcards
what is the nervous system?
network of cells in the brain and body that are responsible for all aspects of what people think, feel, and do
what are the the three functions of the nervous system?
- receives sensory input through the 5 senses
- processes the information in the brain by paying attention, perceiving, and remembering it
- responds to the information by acting on it
what are the two divisions of the brain?
central nervous system & peripheral nervous system
what is the central nervous system?
consist of nerve cells in the brain and the spinal cord
what is the peripheral nervous system?
consists of the nerve cells outside of the brain and spinal cord
how does a neuron communicate?
via a combination of electrical and chemical signals
what are the structures of a neuron?
dendrites, cell body, axon, and terminal buttons
dendrites
branch-like extensions of the cell body with receptors that receive signals from other neurons
cell body
collects and combines the information received from the neurons
axon
long outgrowth from cell body that lets a neuron transmit information to other neurons
terminal buttons
parts of the neuron at the end of axons that releases chemical signals from one neuron to the synapse
synapse
gap between the terminal buttons of a sending neuron and the dendrites of a receiving neuron
what is a neurotransmitter?
chemicals that carry signals from one neuron to another
what are the three phases of neural communication?
transmission phase, reception phase, and integration phase
what is the transmission phase?
electrical signals created in the cell body that travel along the axon and neurotransmitters are released from the terminal buttons into the synapse
what is the reception phase?
neurotransmitters cross the synapse and fit into receptors in the dendrites of the postsynaptic neuron
what is the integration phase?
when each neurotransmitter has either excitatory or inhibitory effects on the postsynaptic neuron. the sum of the effects either cause another action potential or not
what is the resting state?
when the electrical charge inside the neuron is more negative than the charge outside
what is the refractory period?
when the neuron returns to its resting state
*less responsive to incoming stimulation and less likely to fire an action potential
what is an action impulse?
neural impulse that travels along the axon and then caused the release of neurotransmitter into the synapse
presynaptic neuron
neuron that receives the signals
postsynaptic neuron
neuron that receives the signal
to prevent constant stimulation, how are neurotransmitters removed?
through reuptake & enzyme degradation
what is reuptake?
neurotransmitter are reabsorbed by the presynaptic neuron