ch3 Flashcards
neuroanatomy
study of parts and functions of neurons
neurons
individual nerve cells that make up the nervous system
dendrites
root like parts of the cell that grows out the body. makes synaptic connections with other neurons.
cell body/soma
contains the nucleus and other vital parts of the cell
axon
wire like structure that stretches from the cell body and leads to the terminal buttons
myelin sheath
fat that covers the axon of the neurons
terminal buttons
branched ends of axon that contains neurotransmitters
neurotransmitters
chemicals in terminal buttons that allow neurons to communicate. fits into receptor cites (dendrites)
synapse
space between terminal buttons of neuron a and dendrites of neuron b
threshold
(in ch3) minimum amount needed for a neuron to fire
action potential
when a neuron sends info (electric potential charges) down the axon.
all or nothing principle
states that a neuron either fires or it doesn’t. no in between
inhibitory neurotransmitters
prevents neurons from firing
excitatory neurotransmitters
encourages cells to fire
nervous system
made up of 2 sets of neurons (since neurons can only fire 1 direction)
one set fires towards the brain, the other fires from the brain towards the body
afferent/sensory neurons
takes info from nerves to brain
interneurons
takes info once it reaches the brain/spine and directs it to other parts of the brain or efferent neurons
efferent neurons
takes info from the brain to the rest of the body
central nervous system (CNS)
consists of the brain and spinal cord. located in the skull and vertebrae
peripheral nervous system (PNS)
all other nerves not encased in bone (divided into somatic and autonomic nervous system
somatic nervous system
controls voluntary muscle movements
autonomic nervous system
controls autonomic functions (heart lungs, internal organs). and is divided into the sympathetic and parasympathetic nervous systems