Introduction to the Nervous System Flashcards
Somatic Nerve Fibers Conduct impulses from
CNS to skeletal (conscious control of muscles) as opposed to involuntary
autonomic system consists of
visceral nerve fibers
autonomic system regulates
smooth muscle, cardiac muscle, glands
autonomic system is _______ voluntary
involuntary
2 systems of autonomic
sympathetic and parasympathetic
cells of nervous system
neurons and neuroglia
neurons are _______
amitotic, long living, high metabolic rate,
2 names of neuron body
soma or perikaryon
nuclei of neurons are found in the
CNS
ganglia have clusters of neuron cell bodies
in the PNS
CNS contains _____ while PNS contains ______
processes and cell bodies; primarily processes
Tracts
Bundle of Neuron processes in CNS
2 types of processes
dendrites and axons
Cell body in CNS
Nuclei
Cell body in PNS
Ganglia
Processes in CNS
Tracts
Processes in PNS
Nerves
Inside the cell body
rough ER Chromatophilic
dentrites
Transmit signal as Graded Potential and action potential
Graded Potential occurs in
dentrites, cell body, sensory receptor
Action potential occurs in
Axon
Strength of Graded Potential
relatively weak, dissapates with distance
strength of action potential
100 mV all or none
strength of graded potential
hyperpolarizing or depolarizing
strength of action potential
depolarizing
Refractory period of graded potential
none
refractory period of action potential
absolute and relative
channel type responsible for graded potential
mechanical, ligand gated
channel type responsible for action potential
voltage gated
ions involved in graded potential
Ca-, K+, Na+
ions involved in action potential
K+, Na+
Axon starts at the _____
axon hillock
axons have occasional branches called
collaterals
nerve impulses are generated and transmitted along the _____
axolemma
axons rely on cell body to _____
renew proteins and membrane
molecules and organelles are moved along the axons by
motor proteins (dynein and kinesin)
Anterograde
away from the cell body
retrograde
towards the cell body (cells to be degraded, virus, bacteria)
Na+/K+ ATPase is responsible for the
concentration gradient
Resting potential of Electrochemical gradient
-70mV
Passive Channels
Leak Channels (always open)
Passive channels change with _______
Concetration
Active Channels are usually_______
gated/closed
innactivation gate is always except ______
open/depolarized (+30)
Chemically Gated Channels are Usually found _____
Cell Bodies and Dendrites
One of the most common neurotransmitters that open chemically gated channels ____
ACh
Voltage gated channels are most commonly found in ______
neural axons, Sarcolema of muscle cells, skeletal muscle
Mechanically Gated channels are found in _____
Sensory receptors
Voltage gated channels respond to changes in ______
Transmembrane Potential
Graded Potential
Change in transmembrane potential, any stimulus that opens a chemically gated receptor
depolarization
Potential is proportional to the stimulus
Graded potentials tend to
taper off
The effect of graded potential is ________
most affected at site and then decreases, passive, dose-dependent, hyperpolarize, depolarize,
how does a graded potential send a signal down the axon?
action potential
graded potential has to cause a change of 10 mV at the _______ to cause an action potential
axon hillock
three conditions of gated channels
closed but capable of opening (activation gate is closed) but could open; =
activation gate is closed, inactivation is up:
polarized (-70mV)
at 30+ mV, the _______ gates close
inactivation gates
K+ channels open and the
inner membrane becomes less polarized
what happens if you have hyperkalemia?
Takes longer for K+ to flow out of cell, and longer to repolarize
K+ channels begin to close at
-70mV
K+ channels finish closing at
-90mV (hyper polarized)
inactivation gate Na+ gate opens at; activation gate at
-70/-60
inactivation gate Na+ opens ___closes at
-70/+30
activation gate Na+ opens at _____ closes at
-60/-90
why is action potential always moving down the axon?
hyperpolarization prohibits moving backwards
Absolute refractory period
Na+ channels are open and inactive-60=-90
Relative refractory
Almost normal potential -90=-70
2 types of propagation of signal
continuous (unmylinated)/saltatory
Axon Diameters:
a=big, b=medium, c=small
excitatoy/inhibitory depends on the
receptor
Somatic cells go from ______ to ______ in the peripheral nervous system
neuron soma to effector muscle, ACh to skeletal muscle
ANS nerves in sympathetic travel from
nerve to ganglion, deliver ACh, and then postsynaptic nerve from ganglion to gland and then NE to blood stream
ANS nerves in parasympathetic travel from
nerve to ganglion ACh, then to
channel linked neurotransmitter receptors include the ions
Ca+ K+ Na+ Direct and Simple
G coupled protein receptors:
secondary messenger, indirect, cAMP,
Channel Linked receptors
Cholinergic/ligand gated
nicotinic receptors
ion channels, cholinergic: ACh
muscarinic receptors
G-coupled protein, cholinergic: ACh
Adrenergic
NE, alpha and beta
2 types of cholinergic:
nicotinic, muscarinic, bind ACh
Adrenergic
NE
preganglianic neurotransmitter:
ACh
Post ganglianic neurotransmitter:
para: ACh. symp: NE