Unit 2 Flashcards
(149 cards)
basic building blocks of nervous system
neurons
receive, process, and transmit electromagnetic information to muscles, glands and each other
neurons
what are the 4 types of neurotransmitters/chemical messengers
acetylcholine
dopamine
serotonin
endorphins
nervous system
the electrochemical communication system that carries information to and from all parts of the body
CNS
brain and spinal chord
reflexes
PNS
nerves and neurons that connect the CNS to the rest of the body
carries incoming messages to your brain and outgoing signals to your muscles and glands
dendrites
receive incoming messages
cell body (soma)
contains the nucleus of a neuron
nucleus of a neuron
makes the decision to fire or not to fire the message that the dendrite receives
myelin sheath
fatty tissue that insulates the axon, speeding up transmission of the message
node of ranvier
space between the myelin sheaths
axon
longest part of the neuron which the electrical message travels the length of
schwann cells
non-neuronal cells in the CNS that form a myelin sheath
axon terminal buds
the end point of a neuron that releases neurotransmitters into the synapse, hense sending the message on to the next neuron
resting potential
when a neuron is NOT firing, and has a negative charge with mostly potassium ions inside and mostly sodium ions outside
meaning that the neuron is polarized when opposites are AWAY from each other
polarization in a neuron
at resting potential, when sodium is on the outside, potassium on the inside of a neuron
at this state, a neuron is at homeostasis
polarized state
action potential
“nerve impulse” (electrical pulse/message that travels down the length of the axon) - causes the neuron to fire
all or nothing principle
when the nucleus decides to fire, it fires down the axon completely (all the way) or not at all
depolarization in a neuron
when a message begins, sodium ions come in and depolarize or neutralize section of axon
when opposites are no longer away from each other. this happens with action potential like a domino effect
refractory period
potassium ions are pushed out and neuron pauses to reload
the period of time after firing that the neuron is focused on resetting and therefore is unable to fire again
synapse
a gap or open space between neurons, and therefore is not a part of the firing process
neurotransmitter
a chemical substance that crosses the synapse to carry the message to the next neuron
receptor sites
specific points on dendrites of neurons that receive specific types of neurotransmitters