Chapter 9 Nervous Tissue Flashcards
What makes up the central nervous system (CNS)
brain and spinal cord
What makes up the peripheral nervous system (PNS)
cranial nerves and spinal nerves
what is the function of the central nervous system?
control center
what does the peripheral nervous system do?
communicate between CNS and rest of body
What is the division of the nervous system called where information comes in?
sensory
what is the division of the nervous system called where information goes out?
motor nervous system
What two types of cells make up nervous tissue?
neurons
neuroglia (glial)
what do the neurons do?
transmit the action potential
what do the neuroglia (glial) cells do?
support the neuron
what is a nerve made up of?
many what?
neurons
name the pink highlighted region
soma (cell body)
name the pink highlighted region
what does it do?
dendrites
signals received from other sources
name the pink highlighted region
axon
in order, name the parts of the neuron where the action potential travels
dendrite to soma to axon
name the pink highlighted region
what happens here?
axon terminals (synaptic knobs)
where cell communicates with other material
name the pink highlighted region
what happens here?
axon hillock (trigger zone)
the action potential begins
Where do the sensory (afferent) neurons carry information to?
into the brain or spinal cord
where do motor (efferent) neurons carry information to?
out to muscles and glands
Where are interneurons (association) located and where do they carry information to?
located in peripheral nervous system between sensory & motor pathways
Which neuron makes up 90% of our neurons?
interneurons
Are neuroglia (glial cells) electrically excitable?
no
Do neurons or neuroglia multiply and divide by mitosis?
neuroglia
Name the pink highlighted region (what kind of neuroglia is it?)
which nervous system?
what does it do?
oligodendrocyte
central
myelantes (wrap around) neurons
name the pink highlighted section
what does it do?
microglial
phagocytes (macrophage) fights infection
which neuroglia cells myelanate in the peripheral nervous system?
schwann cells
what are the names for the two neurons involved in a synapse?
presynaptic neuron
postsynaptic neuron
what is a ligand-gated channel?
only opens when something binds to it
what happens during depolarization in the cell?
the negative charge becomes less negative and becomes prepared for an action potential
what happens during hyper polarization in the cell?
the negative charge is more negative than resting potential and is not ready to receive action potential stimuli
What is a depolarizing postsynaptic graded potential called?
EPSP
excitatory postsynaptic potential
What is a hyperpolarizing postsynaptic graded potential called?
IPSP
inhibitory postynaptic potential
What is graded temporal summation?
multiple excitatory stimuli firing one right after the other that added together create enough charge for action potential
what happens if i have an excitatory synapse and inhibatory synapse at the same time?
what type of graded potential summation is this called?
they cancel out and never reach threshold for action potential
spacial summation of IPSP and EPSP
what is the action potential threshold charge for the action potential to take place?
-55
what is the sequence of action potential?
- stimulus
- threshold reached
- action potential
- depolarization (Na+ ions in) making positive charge in cell
- repolarization (K+ ions out)
- brief period of hyperpolarization
what is hyperpolarization called after an action potential and why does it occur?
called relative refractory period
to prevent action potential from going backwards
Are sensory neurons called afferent or efferent?
afferent
Are motor neurons called afferent or efferent?
efferent
can each nerve contain sensory and motor neurons?
yes
what happens if i have many excitatory synapses happening at at the same time all over from different nerves and the sum is enough for an action potential?
what type of graded potential summation is this called?
spatial summation of stimuli
what is no summation graded potential?
signals that fire but not in enough quantity or closely enough together to for an action potential
