19 Organization of the Nervous System Flashcards
Nervous System
Transmits info electricaly rapidly along specific pathways
Endocrine System
Uses chemicals (hormones that are distributed ubiquitiusy and more slowly, limited by blood speed.
neurons
nerve cless that are able to conduct nerve impulses
sensory neurons
conduct impulses from receptors to the central nervous system
CNS
central nervous system
Afferent neurons
latin (to carry) , also sensory neurons
Electromagnetic receptors
photo, sensitive to light
chemoreceptors
respond to chemical stimulation
thermoreceptors
respond to mechanical events
pain reciptors
respond to only painful stimuli
somatic neurons
control the skeletal muscles
autonomic neurons
control cardiac muscle, visceral muscle, and certin glands
interneurons
found between the sensory and motor neurons, handle sensor information, fillters out about 99%^
reflex
when a stimulus elicits an immediate response
spinal chord
most primitive level of nervous system control, reflexes
brain stem & cerebellum
second level of system contol , autonomic activities
creberal cortex of the cerebrum
highest level of control, stores info, memory, though process, resson and problem solving
chemical synapse
uses small molecules, rapid acting chemical transmitter substances
acetylcholine
small molecule rapid acting transmiter, systhesized in the synaptic vesicles within the axon terminus
calcium ions
pass into the axon tip from the interstitial fluid after depolerization of the axon
acetlycholinesterase
rapidly metabolizes the transmitters that bind to the approprate receptors in the postsynaptic membrane
depolarize
occurs when an the membran allows positive charges to enter to generate an action potential
ligand gated sodium channels
excitatory chemical transmitters generate action potnetials by binding to recptors on these, allowing sodium ion to diffuse freely into the ccell
excitatory transmitters
acetylcholine, and norepinephrine are examples, generate action potential
hyperpolarized
when the inside of a cell becomes more negative that normal,
inhibitory trnasmitters
block action potentials, exmples GABA and Glycine
Spatial Summation
a minimum of 100 or so diffrent excitatory neurons have to fire simultaneously to excite the cell
Temporal Summation
Some excitatrory cells may fire at high frequency, making the more effective in exciting a cell
excitatory post synaptic potentials (EPSP’s)
potential changes that make the inside less negative
Inhibitory postsynaptic potentials (IPSP’s)
Potential changes that make the potential more negative -65 milivolts to -70 for example,
Postsynaptic inhibition
inhibition using IPSP’s, occurs rapidy for short durration
Presynaptic inhibition
inhibitory neurons act y decreasing the amount of excitatory transmitter released by the presynaptic neuron, by making the neuron less permeable to calcium ions
