Biopsychology: Neurons and Synaptic Transmission Flashcards
what are neurons?
there are 100 billion neurons in the human nervous system, 80% is in the brain. by transmitting signals electrically and chemically, these neurons provide communication for the nervous system.
what are the types of neurons?
sensory = carry messages from peripheral nervous system to the central nervous system. long dendrites and short axons. relay = connect sensory neurons to motor neurons, short dendrites and short axons. motor = connect to the central nervous system to effectors (muscles and glands), short dendrites and long axons.
what’s the structure of a neuron?
cell body = includes a nucleus (contains genetic material). dendrites = carry nerve impulses towards the cell body. axon = carries impulses away from the cell body, it’s covered in a fatty layer of myelin sheath that protects the axon and speeds up electrical transmission.
what’s electric transmission?
when a neuron is in a resting state, the inside of a cell is negatively charged compare to the outside. when a neuron is activated by a stimulus, the inside of the cell becomes positively charged causing an action potential to occur. this creates an electrical impulse that travels down the axon
what’s chemical transmission in synapses?
neurons are seperated by a synapse, the space between the synapses is the synapses cleft as well as the pre and post synaptic receptor sites. signals within neurons are transmitted electrically, while signals between neurons is chemically transmitted by synaptic transmission.
what are neurotransmitters?
chemicals that diffuse across the synapse to the next neuron. once it crosses, it is taken up by the postsynaptic receptor sites. the chemical message is converted back into an electrical impulse
what’s excitation and inhibition?
excitation = when a neurotransmitter increases the positive charge of the postsynaptic neuron, increasing the likelihood of the neuron firing. inhibition = when a neurotransmitter makes the charge of the postsynaptic neuron more negative, decreasing likelihood that the neuron will fire and pass on the electrical impulse.
