Neurons Flashcards
Dendrite
Branch-like structure attached to the soma that receives information from the terminal buttons of other neurons
Axon
Long, thin, tube transferring information from the soma to the terminal buttons
Myelin sheath
Covering over the axon to insulate and increase efficiency and accuracy of message transmission; produced by oligodendrocyte
Terminal button
Knob-like structure at the end of a neuron containing neurotransmitters
Neurotransmitter
Chemical released from a terminal button that has an excitatory or inhibitory effect on another neuron
Sensory neuron
A neuron that gathers information from the environment and sends it to the CNS
Motor neuron
A neuron in the CNS that controls movement and glandular activity
Interneuron
A neuron working between sensory and motor neurons, located within the CNS
Action potential
The brief electrical impulse that causes a rapid reversal of the membrane potential
Membrane potential
A balance of diffusion and electrostatic pressure
Nodes of ranvier
Potential is regenerated, the message seems to jump from node to node
Synapse
Junction between the terminal button of one neuron and the membrane of another
Presynaptic membrane
Membrane of a terminal button through which the neurotransmitter is released
Postsynaptic membrane
Membrane of the cell that receives the chemical message
Synaptic cleft
The space between the presynaptic and postsynaptic membranes filled with extracellular fluid
Excitatory postsynaptic potential (EPSP)
Excitatory depolarization of the postsynaptic membrane caused by neurotransmitter
Inhibitory postsynaptic potential (ISPS)
Inhibitory hyperpolarization of the postsynaptic membrane caused by neurotransmitters
Reuptake
Removal of neurotransmitter from the synaptic cleft by the terminal buttons taking it back up
Enzymatic deactivation
Destruction of molecules of neurotransmitter by an enzyme
Neuromodulators
Naturally secreted substances that act like neurotransmitters but are not restricted to the synaptic cleft
Hormones
Substances produced in and secreted by cells and organs, distributed through the bloodstream, to affect the activity of target cells that contain specialized receptors
Soma
Cell body containing the nucleus, filled with cytoplasm containing special structures such as mitochondria
