12.1 Neuronal Structure and Function Flashcards
What is a neuron?
specialized cell that transmits and processes information from one part of the body to another
What are action potentials?
localized area of depolarization of the plasma membrane that travels in a wave like manner along an axon
What is synaptic transmission?
when an action potential reaches the end of an axon at a synapse and the signal is transformed into a chemical signal by the release of a neurotransmitter into the synaptic cleft
What is soma?
central body of the neuron
What are axons and dendrites?
slender projections that extend from the cell body of a neuron
What is a bipolar neuron?
neuron with one dendrite
What is a multipolar neuron?
neuron with multiple dendrites
What are synaptic knobs?
termination point of branches axons that forms connections with target cells
What is the synaptic cleft?
microscopic space between the axon of one neuron and the cell body or dendrite of a second neuron, or between axon and organ
What is the resting membrane potential?
electrical potential across the plasma membrane of approximately -70mV with the interior of the cell negatively charge in respect to the exterior
What are the two primary membrane proteins responsible for the resting membrane potential?
Na/K ATPase
potassium leak channels
What do Na/K ATPases do?
pump three sodium ions out of the cell and two potassium ions into the cell
What do potassium leak channels do?
open all the time and allow potassium to leak across the membrane according to their gradient (out of the cell)
What is depolarization?
change in the membrane potential from resting to less negative and sometimes even positive
What is repolarization?
when the membrane returns to normal resting potential
