Nervous Tissue Connect Assignment
Voltage is a measure of relative energy.
potential
Voltage represents ______ energy.
potential
Propagation of depolarization only flows away from the cell body towards the synaptic knob because ______.
previous regions in the axon have sodium channels in the inactive state
Membrane molecules that use the energy of ATP to move ions against a concentration gradient are called .
pumps
A return of the membrane potential towards the resting membrane potential immediately the following depolarization is called ______.
repolarization
Na+ and K+ leak channels and Na+/K+ pumps on the neuron are responsible for establishing and maintaining the membrane .
resting potential
The function of a neuron is dependent on ______.
resting membrane potentials changing
"An action potential either happens or it doesn't." This statement could also be called ______.
the all-or-none law
True or false: Graded potentials vary in size depending on the stimulus.
true
The voltage-gated sodium channels undergo changes in activity during the depolarization phase of an action potential. Place these in order from first to last.
1. the membrane potential is -70 mv. 2. sodium ions flow into the neuron. 3. the membrane potential becomes more positive. 4. voltage-gated sodium ion channels open.
Match the type of circuit to the corresponding letter.
A- converging B- diverging C- reverberating D- parallel-after-discharge
Action potentials are always propagated along an axon at the same ______ but ______ can vary depending on the strength of the stimulus.
Amplitude/ Frequency
Which of the following pumps can you find in the plasma membrane?
Ca2+ Na+/K+
Repolarization is due to the opening of voltage-gated _______ and the subsequent movement of _____ out of the cell.
K+/K+
The threshold is reached when the ______ ions flow into the cell.
Na+
The nerve impulse has the voltage-gated ______ channels opened first followed by the opening of the voltage-gated ______ channels.
Na+; K+
True or false: Voltage-gated sodium ion channels are closed initially and the membrane potential is -70 mv.
True
The voltage-gated sodium channels ______ during repolarization.
are inactivated
The myelin sheath covers ______.
axon
Many excitatory neurotransmitters cause the opening of channels that allow for the flow of ______.
both Na+ and K+
The ependymal cells help produce ______.
cerebrospinal fluid
The total length of the axon is called the segment.
conductive
The main activity of the ______ is the propagation of an action potential along the axolemma.
conductive segment
The type of circuit letter A represents is a circuit.
converging
A positive change in the membrane potential is called ______.
depolarization
Glial cells ______ transmit electrical impulses.
do not
Creating and transmitting currents is central to the function of neuron physiology.
electrical
A difference in the number of charged particles between two sides of the membrane forms a(n) ______.
electrical gradient
The choroid plexus is made from capillaries and ______.
ependymal cells
A larger axon transmits an impulse ______ than a smaller axon.
faster
Match the neurotransmitter to its class.
glutamate = amino acid norepinephrine = monoamine
The event that occurs when the inside of a cell becomes more negative than the resting membrane potential is called .
hyperpolarization
The electrical gradient in a resting neuron is such that the of the cell is negative relative to the .
inside outside
Neuronal pools are made of ______.
interneurons
During an action potential, voltage-gated potassium channels open after voltage-gated sodium channels. The effect this has on the membrane potential is ______.
it becomes less positive and more negative
The brain interprets the increased frequency of nerve signals as a ______ stimulus.
more intense
Neuronal pools are also called ______.
neuronal pathways neuronal circuits
Place the events of an EPSP in order.
1. Excitatory neurotransmitter binds to chemically gated cation channel 2. More Na+ enters the postsynaptic cell than K+ leaves 3. The inside of the cell becomes more positive 4. The local current of Na+ becomes weaker as it moves towards the axon hillock
______ is the return of polarity from positive back to negative (the RMP).
Repolarization
Which describes the propagation of depolarization down an axon?
The flow of Na+ to downstream regions causes depolarization of adjacent regions.
The nerve impulse causes ______ in the number of calcium ions that enter the synaptic knob.
an increase
The voltage-gated potassium channels ______ during repolarization.
are open
The presence of ______ ions causes the synaptic vesicles to bind to the membrane, allowing neurotransmitters to be released.
calcium
The event that occurs when the inside of the cell becomes more positive (less negative) than the resting membrane potential is called .
depolarization
Match the neurotransmitter with its correct class.
glycine = amino acid dopamine = monoamine neuropeptide = enkephalin
A potential that is a temporary change in membrane potential which lasts only as long as the stimulus that causes it and can vary in size is called a potential.
graded
The presence of a sheath increases the rate of impulse conduction.
myelin
A ______ is the propagation of an action potential along an axon.
nerve impulse
The sequential opening of voltage-gated sodium channels is followed by the sequential opening of voltage-gated channels.
potassium
Which of the following membrane transporters are present throughout the membrane of a neuron?
potassium leak channels sodium leak channels Na+/K+ pumps
The functions of astrocytes are to ______.
regulate the composition of interstitial fluid help form the blood-brain barrier assist neuronal development
The flow of ______ ion is the most common cause of depolarization.
sodium
The conductive segment of a neuron is/are the ______.
total length of the axon
The measure of the difference in electrical charge between two areas is called a .
voltage
If a subthreshold value is reached on an axon membrane, an action potential ______.
will not occur
Initially, the voltage-gated Na+ channels are closed and the membrane potential is ______ mV. As Na+ flows in the membrane potential changes to ______ mV and the threshold is reached.
-70; -55