Bio 669 Quiz 2 |Gradient Potential|
Neurons| Electrons| Complete Mock
Exam 2024/2025
What is the primary function of neurons in the nervous system?
Neurons transmit signals throughout the body to facilitate communication between the brain
and other body parts.
What is the resting membrane potential of a typical neuron?
Approximately -70 mV.
How does the concentration gradient influence ion movement across a neuron's membrane?
Ions move from areas of high concentration to areas of low concentration.
What role do sodium ions play during the action potential?
Sodium ions enter the neuron, causing depolarization.
What is depolarization in the context of neuron function?
It is the process by which the membrane potential becomes less negative, moving toward
zero.
How do potassium ions contribute to the repolarization phase of an action potential?
1
, Potassium ions exit the neuron, returning the membrane potential to its resting state.
What is the term for the period after an action potential during which a neuron cannot fire
another action potential?
The refractory period.
How do myelin sheaths affect nerve signal transmission?
They increase the speed of electrical impulses along the axon.
What is the significance of the axon hillock in neuron signaling?
It is the site where action potentials are initiated if the threshold is reached.
How do neurotransmitters influence neuron communication?
They bind to receptors on the postsynaptic neuron, causing changes in membrane potential.
What is synaptic transmission?
The process of communication between neurons at the synapse.
How does the electrochemical gradient affect the movement of ions in and out of neurons?
It determines the direction and magnitude of ion flow based on both concentration and
electrical gradients.
2
, What is the role of calcium ions in neurotransmitter release?
Calcium ions trigger the fusion of neurotransmitter vesicles with the presynaptic membrane.
What is an excitatory postsynaptic potential (EPSP)?
It is a temporary depolarization of the postsynaptic membrane potential, making it more
likely to fire an action potential.
What is an inhibitory postsynaptic potential (IPSP)?
It is a temporary hyperpolarization of the postsynaptic membrane potential, making it less
likely to fire an action potential.
How do graded potentials differ from action potentials?
Graded potentials vary in amplitude and decrease over distance, while action potentials are
all-or-nothing events.
What is the role of the sodium-potassium pump in maintaining resting membrane potential?
It actively transports sodium out of and potassium into the neuron, maintaining the
concentration gradients.
How does the blood-brain barrier protect the brain?
It prevents harmful substances in the bloodstream from entering the brain's extracellular
fluid.
3
Neurons| Electrons| Complete Mock
Exam 2024/2025
What is the primary function of neurons in the nervous system?
Neurons transmit signals throughout the body to facilitate communication between the brain
and other body parts.
What is the resting membrane potential of a typical neuron?
Approximately -70 mV.
How does the concentration gradient influence ion movement across a neuron's membrane?
Ions move from areas of high concentration to areas of low concentration.
What role do sodium ions play during the action potential?
Sodium ions enter the neuron, causing depolarization.
What is depolarization in the context of neuron function?
It is the process by which the membrane potential becomes less negative, moving toward
zero.
How do potassium ions contribute to the repolarization phase of an action potential?
1
, Potassium ions exit the neuron, returning the membrane potential to its resting state.
What is the term for the period after an action potential during which a neuron cannot fire
another action potential?
The refractory period.
How do myelin sheaths affect nerve signal transmission?
They increase the speed of electrical impulses along the axon.
What is the significance of the axon hillock in neuron signaling?
It is the site where action potentials are initiated if the threshold is reached.
How do neurotransmitters influence neuron communication?
They bind to receptors on the postsynaptic neuron, causing changes in membrane potential.
What is synaptic transmission?
The process of communication between neurons at the synapse.
How does the electrochemical gradient affect the movement of ions in and out of neurons?
It determines the direction and magnitude of ion flow based on both concentration and
electrical gradients.
2
, What is the role of calcium ions in neurotransmitter release?
Calcium ions trigger the fusion of neurotransmitter vesicles with the presynaptic membrane.
What is an excitatory postsynaptic potential (EPSP)?
It is a temporary depolarization of the postsynaptic membrane potential, making it more
likely to fire an action potential.
What is an inhibitory postsynaptic potential (IPSP)?
It is a temporary hyperpolarization of the postsynaptic membrane potential, making it less
likely to fire an action potential.
How do graded potentials differ from action potentials?
Graded potentials vary in amplitude and decrease over distance, while action potentials are
all-or-nothing events.
What is the role of the sodium-potassium pump in maintaining resting membrane potential?
It actively transports sodium out of and potassium into the neuron, maintaining the
concentration gradients.
How does the blood-brain barrier protect the brain?
It prevents harmful substances in the bloodstream from entering the brain's extracellular
fluid.
3
