The Nervous Systems Flashcards
specialized cells capable of transmitting electrical impulses and then translating those electrical impulses into chemical signals
neurons
highly specialized cells responsible for the conduction of impulses
neurons
neurons communicate using both…
electrical and chemical forms of communication
[blank] occurs via ion exchange and the generation of membrane potential down the length of the axon
electrical communication
[blank] occurs via neurotransmitter release from the presynaptic cell and the binding of these neurotransmitters to the postsynaptic cell
chemical communication
[blank] are appendages that receive signals from other cells
dendrites
[blank] is the location of the nucleus as well as organelles such as the endoplasmic recticulum and ribosomes
soma or cell body
[blank] is where the cell body transitions to the axon, and where action potentials are initiated
axon hillock
[blank] is a long appendage down which an action potential travels
axon
[blank] is the end of the axon from which neurotransmitters are released
nerve terminal or synaptic bouton
[blank] are exposed areas of the myelinated axons that permit saltatory conduction
Nodes of Ranvier
[blank] consists of the nerve terminal of the presynaptic neuron, the membrane of the postsynaptic cell, and the space between two
synapse
[blank] the space between the presynaptic neuron and the postsynaptic cell
synaptic cleft
many axons are covered in [blank]
myelin
[blank] is an insulating substance that prevents signal loss
myelin
[blank] creates myelin in the central nervous system (CNS) and Schwann cells in the peripheral nervous system (PNS)
oligodendrocytes
individual axons are bundled into…
nerves or tracts
a single nerve may carry multiple…
types of information including sensory, motor, or both
tracts only contain [blank] type of information
one
cell bodies of neurons of the same type within a nerve cluster together in the [blank] in the PNS
ganglia
cell bodies of the individual neurons within a tract cluster together in the [blank] in the CNS
nuclei
other cells within the nervous system in addition to neurons include…
neuroglia or glial cells
[blank] nourish neurons and form the blood-brain barrier
astrocytes
[blank] controls the transmission of solutes from the bloodstream into nervous tissue
blood-brain barrier
[blank] line the ventricles of the brain and produce cerebrospinal fluid
ependymal cells
[blank] physically supports the brain and serves as a shock absorber
cerebrospinal fluid
[blank] are phagocytic cells that ingest and break down waste products and pathogens in the CNS
microglia
[blank] and [blank] produce myelin around the axons
oligodendrocytes (CNS) and Schwann cells (PNS)
all neurons exhibit a [blank] of approximately -70mV
resting membrane potential
resting potential is maintained using [blank] and [blank]
selective permeability of ions and the Na+/K+ ATPase
[blank] pumps three sodium ions out of the cell for ever 2 potassium ions pumped in
Na+/K+ ATPase
icoming signals can either be [blank] or [blank]
excitatory or inhibitory
[blank] cause depolarization of the neuron
excitatory signals
[blank] cause hyperpolarization of the neuron
inhibitory signals
[blank] refers to the integration of multiple signals near each other in time
temporal summation
[blank] refers to the addition of multiple signals near each other in space
spatial summation
a [blank] is used to propagate signals down the axon
action potential
when enough excitatory stimulation occurs, the cell is [blank] to the [blank] and voltage-gated sodium channels open
depolarized// threshold voltage
sodium flows into the neuron due to its strong [blank] … this continues to depolarize the neuron
electrochemical gradient
at the peak of the action potential (approximately +35mV), sodium channels are [blank] and potassium channels [blank]
inactivated// open
potassium flows out of the neuron due to its strong electrochemial gradient which [blank] the cell
repolarizes
potassium channels stay open long enough to overshoot the action potential resulting in a [blank] neuron
hyperpolarized
the [blank] brings the neuron back to the resting potential and restores the sodium and potassium gradients
Na+/K+ ATPase
while the axon is hyperpolarized it is in its [blank]
refractory period
during the [blank] the cell is unable to fire another action potential
absolute refractory period
during the [blank] the cell requires a larger than normal stimulus to fire an action potential
relative refractory period
at the [blank] neurotransmitters are released into the synapse
nerve terminal
when the action-potential arrives at the nerve terminal, [blank] open
voltage-gated calcium channels
the influx of calcium causes [blank] of vesicles filled with neurotransmitter with the presynaptic membrane, resulting in [blank] of neurotransmitter into the synaptic cleft
fusion// exocytosis
the neurotransmitters [blank] to receptors on the postsynaptic cell, which may be [blank] or [blank] receptors
bind// ligand-gated ion channels// G protein-coupled
neurotransmitters must be cleared from the [blank] to stop the propagation of the signals
postsynaptic receptors
the neurotransmitter can be [blank] broken down
enzymatically
the neurotransmitter can be absorbed back into the presynaptic cell by [blank]
reuptake channels
the neurotransmitter can [blank] out of the synaptic cleft
diffuse
there are three types of neurons in the nervous system
motor (efferent), interneurons, and sensory (afferent) neurons
MESA (mom eats spaghetti alot)
motor–efferent, sensory–afferent
the nervous system is made up of the [blank] and the [blank]
central nervous system// peripheral nervous system
central nervous system (CNS) contains
brain and spinal cord
peripheral nervous system (PNS) contains
cranial and spinal nerves
in the CNS [blank] consists of myelinated axons
white matter
in the CNS [blank] consists of unmyelinated cell bodies and dendrites
grey matter
in the brain [blank] is deeper than [blank]
white matter// grey matter
in the spinal cord [blank] is deeper than [blank]
grey matter// white matter
the PNS is divided into the [blank] and [blank] nervous systems
somatic (voluntary) and autonomic (automatic)
SVAA (so very awesome abby)
somatic–voluntary// autonomic–automatic
the autonomic nervous system is further divided into the [blank] and [blank] branches
parasympathetic (rest-and-digest) and sympathetic (flight-or-fight)
[blank] use the ability of interneurons in the spinal cord to relay information to the source of a stimulus while simultaneously routing it to the brain
reflex arcs
in a [blank] the sensory (afferent,presynaptic) neuron fires directly onto the motor (efferent, postsynaptic)
monosynaptic reflex arcs
in a [blank] the sensory neuron may fire onto a motor neuron as well as interneurons that fire onto another motor neurons
polysnaptic reflex arcs
