Chapter 12 A&P 207 Smart Book
Neurotransmitters are stored in ______.
synaptic vesicles
To ______ is the basic function of a neuron.
transmit nerve impulses
Some antidepressant drugs are SSRIs. SSRI stands for
Selective Serotonin Reuptake Inhibitors
What is the primary tissue of the nervous system?
nervous tissue
The thin outer layer of the neurolemmocyte is called the ______.
neurilemma
There are ______ different types of glial cells in the CNS.
4
The leak of potassium ions tends to drive the membrane potential to -90 millivolts, and yet the normal resting membrane potential (RMP) of a neuron is around -70 millivolts. What is the reason for this difference?
A small leak of sodium ions makes the RMP more positive
The brain and spinal cord are part of the ______.
Central Nervous System (CNS)
True or false: Graded potentials vary in size depending on the stimulus.
True
True or false: There are more potassium leak channels in a neuron membrane than sodium leak channels.
True
Action potentials are always propagated along an axon at the same ______ but ______ can vary depending on the strength of the stimulus.
amplitude; frequency
The perivascular feet of the ______ help create a blood-brain barrier.
astrocyte
______ are star shaped.
astrocytes
The myelin sheath covers ______.
axon
A nerve is a bundle of parallel
axons or fibers
Most synapses in the human body are ______ synapses.
chemical
A difference in the number of charged particles between two sides of the membrane forms a(n) ______.
electrical gradient
A motor neuron is a ______ classification of a neuron.
functional
Negatively charged proteins and other large organic molecules are found in ______.
greater amounts inside a neuron
functional classes of neurons
interneurons sensory neurons motor neurons
The myelin sheath is made of a high percentage of ______.
lipids
The resting membrane potential is measured in ______.
millivolts
Interneurons are ______ neurons.
multipolar
A cablelike bundle of axons in the peripheral nervous system is called a
nerve
Nervous tissue is composed of
neurons and glial cells
Chemicals that are released from synaptic knobs and bind to receptors on postsynaptic membranes are called
neurotransmitters
______ are released from neurons in response to conductive activity.
neurotransmitters
When sodium ions flow into a cell through a leak channel they make the membrane potential more
positive
Voltage represents ______ energy.
potential
A ______ transmits an impulse through its axon toward the synapse.
presynaptic neuron
The functions of astrocytes are to ______.
regulate the composition of interstitial fluid, help form the blood-brain barrier, and assist neuronal development.
The relative difference in charge across the plasma membrane of a resting neuron is known as the
resting membrane potential
The function of a neuron is dependent on ______.
resting membrane potentials changing
The removal of neurotransmitters from the synaptic cleft by transport into the synaptic knob is known as ______.
reuptake
characteristics of neurons
secretion conductivity extreme longevity excitability amitotic
In retrograde transport, substances are moved ______ the cell body.
toward
Vesicles involved in retrograde transport are moving ______ the cell body.
toward
______ are released from synaptic knobs into the synaptic cleft.
Neurotransmitters
Cytoplasm within an axon is called ______.
axoplasm
The synapse is located ______ the presynaptic neuron and postsynaptic neuron
between
A synapse is a junction ______.
between a neuron and another cell
two structural examples of sensory neurons
bipolar unipolar
The ependymal cells help produce ______.
cerebrospinal fluid
Another way for the neurotransmitter to be removed from the synaptic cleft is by ______ where there is uptake by surrounding glial cells.
diffusion
The choroid plexus is made from capillaries and ______.
ependymal cells
cells that are part of the central nervous system
ependymal cells microglia oligodendrocyte astrocyte
______ is responsiveness to a stimuli.
excitability
Neurons are ______.
excitable cells that transmit electrical signals
It usually takes ______ neurolemmocytes to myelinate one axon.
many