Quiz 1 Vocab Flashcards
presynaptic terminal
swelling at the end of each axon branch
axon
a thin fiber of consistent diameter which conveys an impulse toward other neurons, an organ, or a muscle
blood-brain barrier
mechanism that excludes most chemicals from the vertebrae brain
dendrites
branching fibers on the cell that get narrower near their ends and receive information from other neurons through synaptic receptors
glia
several types of cells that perform different functions such as a neuroglia
internueron
a cell with its dendrites and axons entirely contained within a single structure such as an intrinsic neuron
membrane
the surface of the cell such as the plasma membrane
motor neuron
with its soma in the spinal cord, it receives excitation through its dendrites and conducts impulses along its axon to a muscle
myelin sheath
an insulating material that covers many vertebrae axons. it is composed of fats and proteins
neuron
receives information and transmits it to other cells
nucleus
the structure that contains the chromosomes
sensory neuron
is specialized to be highly sensitive to a particular type of stimulation such as light, sound, touch, etc.
thiamine
enables the body to process glucose such as vitamin B
absolute refectory period
the period in which the membrane cannot produce another action potential regardless of the stimulation
action potentials
messages sent by axons
all-or-none law
is when the amplitude and velocity of an action potential are independent of the intensity of the stimulus that initiated it, provided that the stimulus reached the threshold
electrical gradient
is maintaining the electrical charge between the inside and outside of the cell, such as polarization
hyperpolarization
refers to the change in the charge of a neuron when a negative charge is applied to the negative potential inside the axon which creates an increase in polarization
local neurons
neurons without an axon that only exchange information with their closet neighbors
resting potential
the difference in voltage between the inside and outside of a cell
sodium-potassium pump
a protein complex that repeatedly transports three sodium ions out of the cell while drawing two potassium ions into it
threshold
a “limit” that when surpassed produces a massive depolarization of the membrane which opens the membrane’s sodium channels
