WorksheetsSynapses Chapter 11
Total questions: 47
Worksheet time: 24mins
What is the function of the axon of a presynaptic neuron?
To receive signals from other neurons
To transmit signals to the synapse
To process information within the neuron
To store neurotransmitters
What is the role of synapses in neural communication?
To store genetic information
To transmit electrical signals
To facilitate communication between neurons
To produce energy for the neuron
What is the cell body (soma) of a postsynaptic neuron responsible for?
Transmitting signals to other neurons
Receiving signals from the synapse
Storing neurotransmitters
Producing electrical impulses
What type of synapse connects an axon to a dendrite?
Axodendritic synapse
Axosomatic synapse
Axoaxonal synapse
Dendritic synapse
Which part of the neuron is directly involved in axosomatic synapses?
Dendrites
Cell body
Axon
Synaptic cleft
What is the function of axoaxonal synapses?
Connects axon to dendrite
Connects axon to cell body
Connects axon to another axon
Connects dendrite to cell body
What is the primary function of neurotransmitters in the nervous system?
To transmit signals across a synapse
To store energy in cells
To provide structural support to neurons
To protect neurons from damage
What is the primary function of chemical synapses in neurons?
To transmit electrical signals directly
To transmit signals using neurotransmitters
To store energy for the neuron
To protect the neuron from damage
What is the role of chemical synapses in neuron communication?
They transmit signals using electrical impulses.
They transmit signals using neurotransmitters.
They block signals between neurons.
They transmit signals using magnetic fields.
What enters the axon terminal when voltage-gated Ca²⁺ channels open?
Na⁺ ions
K⁺ ions
Ca²⁺ ions
Cl⁻ ions
What is the role of voltage-gated Ca²⁺ channels in chemical synapses?
They release neurotransmitters directly.
They allow Ca²⁺ to enter the axon terminal.
They block neurotransmitter release.
They transport neurotransmitters across the synaptic cleft.
What happens when Ca²⁺ enters the axon terminal?
It causes synaptic vesicles to release neurotransmitters by exocytosis.
It inhibits the release of neurotransmitters.
It causes the axon terminal to shrink.
It blocks the synaptic cleft.
What is the role of voltage-gated Ca²⁺ channels in chemical synapses?
They allow Na⁺ to enter the axon terminal.
They release neurotransmitters directly.
They open to allow Ca²⁺ to enter the axon terminal.
They bind neurotransmitters to receptors.
What happens after Ca²⁺ entry in the axon terminal?
Neurotransmitters are degraded.
Synaptic vesicles release neurotransmitters by exocytosis.
The axon terminal becomes hyperpolarized.
Voltage-gated Na⁺ channels open.
What occurs when neurotransmitters diffuse across the synaptic cleft?
They are absorbed by the presynaptic neuron.
They bind to specific receptors on the postsynaptic membrane.
They are converted into electrical signals.
They cause the synaptic cleft to close.
What triggers the release of neurotransmitters in a chemical synapse?
Entry of Na+ ions
Entry of K+ ions
Entry of Ca2+ ions
Entry of Cl- ions
What happens after neurotransmitters diffuse across the synaptic cleft?
They are absorbed by the presynaptic neuron
They bind to specific receptors on the postsynaptic membrane
They are converted into electrical signals
They are broken down by enzymes
What is the result of neurotransmitter binding to ion channels on the postsynaptic membrane?
Initiation of an action potential
Graded potentials
Complete depolarization
Hyperpolarization
What triggers the release of neurotransmitters in a chemical synapse?
Entry of Na+ ions
Entry of K+ ions
Entry of Ca2+ ions
Entry of Cl- ions
What happens after neurotransmitters diffuse across the synaptic cleft?
They are absorbed by the presynaptic neuron.
They bind to specific receptors on the postsynaptic membrane.
They are immediately degraded by enzymes.
They cause the synaptic cleft to close.
How are neurotransmitter effects terminated in a synapse?
By reuptake through transport proteins
By binding to the presynaptic neuron
By increasing synaptic cleft size
By converting into ions
What is an EPSP?
A local depolarization of the postsynaptic membrane
A local hyperpolarization of the postsynaptic membrane
A decrease in neurotransmitter release
A type of inhibitory synaptic potential
What effect do EPSPs have on a neuron?
They bring the neuron closer to the action potential threshold
They inhibit the neuron from reaching the action potential threshold
They decrease the membrane potential
They have no effect on the neuron
What happens when neurotransmitters bind to chemically gated ion channels during an EPSP?
Na+ and K+ pass simultaneously
Only Na+ passes through
Only K+ passes through
No ions pass through
What is an IPSP?
A local depolarization of the postsynaptic membrane.
A local hyperpolarization of the postsynaptic membrane.
A global depolarization of the presynaptic membrane.
A global hyperpolarization of the presynaptic membrane.
What effect do IPSPs have on a neuron?
Drive the neuron towards the AP threshold.
Drive the neuron away from the AP threshold.
Have no effect on the AP threshold.
Cause the neuron to fire an action potential.
What happens when neurotransmitter binding occurs in the context of IPSPs?
Opens voltage-gated ion channels.
Opens chemically gated ion channels.
Closes chemically gated ion channels.
Closes voltage-gated ion channels.
Which ions are involved in the permeability change during an IPSP?
Na+ or Ca2+
K+ or Cl-
Na+ or Cl-
K+ or Ca2+
What does the diagram illustrate about the integration of EPSPs and IPSPs in a postsynaptic neuron?
Temporal summation of EPSPs
No summation of EPSPs
Spatial summation of EPSPs
Inhibition of EPSPs
What is the resting potential of the postsynaptic neuron as shown in the diagram?
-55 mV
0 mV
-70 mV
-40 mV
Which synapse is labeled as E₁ in the diagram?
Inhibitory synapse
Excitatory synapse 1
Excitatory synapse 2
Postsynaptic synapse
What does the diagram illustrate about neural integration?
Temporal summation of excitatory postsynaptic potentials (EPSPs)
Spatial summation of inhibitory postsynaptic potentials (IPSPs)
Temporal summation of inhibitory postsynaptic potentials (IPSPs)
Spatial summation of excitatory postsynaptic potentials (EPSPs)
What happens when two excitatory stimuli occur close in time according to the diagram?
They cause EPSPs that add together
They cause IPSPs that cancel each other
They cause EPSPs that cancel each other
They cause IPSPs that add together
What does spatial summation refer to in neural integration?
The process where multiple stimuli at different locations cause EPSPs that add together.
The process where a single stimulus causes multiple EPSPs over time.
The process where inhibitory synapses prevent EPSPs from occurring.
The process where EPSPs and IPSPs cancel each other out.
What does the diagram illustrate about the integration of EPSPs and IPSPs?
Temporal summation of EPSPs and IPSPs
Spatial summation of EPSPs and IPSPs
Chemical synapse transmission
Electrical synapse transmission
What effect do changes in membrane potential have according to the diagram?
They always increase the potential
They can cancel each other out
They only decrease the potential
They have no effect on the potential
Where do graded potentials typically occur?
Axon hillock and axon
Cell body and dendrites
Synaptic cleft
Myelin sheath
What is the typical distance traveled by an action potential?
Short distance within cell body
Long distance from trigger zone through entire length of axon
Across the synaptic cleft
Within the dendrites
In which part of the neuron do action potentials typically occur?
Dendrites
Cell body
Axon hillock and axon
Synaptic cleft
What is the characteristic of the amplitude in graded potentials?
Various sizes (graded); decays with distance
Always the same size (all-or-none); does not decay with distance
Always increasing; decays with distance
Various sizes; does not decay with distance
What triggers the opening of ion channels in action potentials?
Chemical (neurotransmitter) or sensory stimulus
Voltage (depolarization, triggered by GP reaching threshold)
Light, pressure, temperature
Mechanical force
Which type of potential has a positive feedback cycle?
Graded potential
Action potential
Both graded and action potentials
Neither graded nor action potentials
How does repolarization occur in graded potentials?
Voltage independent; occurs when stimulus is no longer present
Voltage regulated; occurs when Na⁺ channels inactivate and K⁺ channels open
Always occurs with a stimulus
Occurs only with chemical stimuli
Which type of potential allows for summation to increase its amplitude?
Graded Potential (GP)
Action Potential (AP)
Both GP and AP
Neither GP nor AP
What is the nature of an action potential in terms of summation?
It can summate to increase amplitude
It is an all-or-none phenomenon
It decreases in amplitude with distance
It can only occur with multiple stimuli
What type of signaling is associated with excitatory postsynaptic potential (EPSP)?
Long-distance signaling
Short-distance signaling; depolarization
Short-distance signaling; hyperpolarization
No signaling
What is the function of inhibitory postsynaptic potential (IPSP)?
Depolarization that spreads to axon hillock
Hyperpolarization that spreads to axon hillock
Long-distance signaling
No effect on membrane potential
