Flashcards in nervous system Deck (93):
"fight or flight"
"rest and digest"
the central vervous system consists of what
brain and spinal cord
the peripheral nervous system consists of what
nerves and ganglia
What are the two major divisions of the PNS?
sensory (afferent) and motor (efferent)
What are the two major divisions of the motor nervous system?
somatic (voluntary) and autonomic (involuntary)
What are the two divisions of the autonomic nervous system?
sympathetic (fight or flight) and parasympathetic (rest and digest)
What is the big difference between neurons and neuroglia?
neurons send and receive electrical messages (excitable)
neuroglia support and protect neurons but don't send or receive electrical messages
make myelin in the CNS
make myelin in the PNS
produce and circulate cerebrospinal fluid
clean up dead and damaged cells in the CNS
most abundant and versatile glial cell, forms blood-brain barrier
surround nerve cell bodies in the PNS
short, numerous, receptive processes of neurons
long, conductive process, carries impulse away from the neuron cell body
biosynthetic center of a neuron
chromatophilic substance, rough ER in a nerve cell body
bundles of fibers inside a nerve that help with structure and stability
"aging pigment" that is a lysosomal product
cone-shaped first part of an axon where the impulse is initiated
branches of the axon
secretive ends of a neuron
enlarged ends of axon terminals
store neurotransmitter inside synaptic bulb
when things are transported from the cell body toward the axon terminals
when things are transported from the axon terminals toward the cell body
fatty covering over an axon that allows messages to travel faster
myelin sheath gaps
nodes of Ranvier
the lighter regions of the brain and spinal cord covered in myelin
the darker regions of the brain and spinal cord not covered in myelin
clumps of cell bodies in the CNS
clumps of cell bodies in the PNS
bundles of axons in the CNS
bundles of axons outside the CNS
the exposed portion of a Schwann cell membrane
Give 2 reasons retrograde transport is significant.
allows some viruses to move to the cell body and used as a tool for introducing viruses to treat genetic disorders
Which structural neuron type is most common?
Which structural neuron type is least common?
What happens to opposite charges?
What is needed to keep opposite charges apart?
the difference in charge across a membrane
What happens when opposite charges are allowed to come together?
energy is released
the unit used to measure the difference in charge between two points
a tool to measure the difference in charge between two points
the flow of electrical charge from one point to another
the hindrance to current flow
the relationship between current, voltage, and resistance is shown by this
substances with high electrical resistance
substances with low electrical resistance
What provides resistance to current in neurons?
plasma (cell) membrane
the chemicals which serve as ion channels
channels that are always open
channels that open when a specific neurotransmitter binds to it
chemically (ligand) gated
channels that open and close in response to changes in the membrane potential
channels that open when receptors are physically deformed
how ions move passively from high to low concentration and toward opposite charges
the difference in charge on either side of a resting neuron membrane
having opposite charged ends or sides
a loss of charge difference
an increase in membrane resting potential, the inside becomes more negative
a local change in membrane potential, magnitude varies with signal strength
the minimum stimulus needed to cause a response
a weak stimulus that doesn't cause a response
when the message is sent along the axon
the nerve either sends the message or doesn't, nothing in between
the time when a neuron can not respond
absolute refractory period
the time when the threshold stimulus is greatly elevated
relative refractory period
How are the gates arranged when the neuron is resting?
What gates open to depolarize the membrane and send the action potential
What gates open to repolarize the membrane?
a nerve impulse, long-distance signal
What is the purpose of graded potentials?
cause action potentials
What 2 factors affect the speed of a nerve impulse?
diameter of fiber and amount of myelin
slow impulse conduction in unmyelinated fiber
fast impulse conduction in myelinated fibers
an autoimmune disease characterized by hardened lesions on the myelin sheaths
large diameter fibers with thick myelin, fastest
small, unmyelinated fibers, slowest
medium thick fibers with light myelin
quick successive stimuli summate to increase the amplitude of a graded potential
multiple stimuli at different locations increases the amplitude of a graded potential
immature nerve cells
What happens to most neuroblasts
die if don't make good connections
Why are most tumors of the nervous system gliomas?
neurons are so specialized that they have lost the ability to divide
What three things disrupt nerve messages?
local anesthetics block Na channels
cold and pressure disrupt blood flow