Neuroscience Action Potential Quiz

<p>They help to maintain the resting membrane potential. (C)</p> Signup and view all the answers

<p>The activation of the sodium-potassium pump. (C)</p> Signup and view all the answers

<p>Entry of Ca2+ ions (B)</p> Signup and view all the answers

<p>Ca2+ influx through voltage-gated Ca2+ channels (A)</p> Signup and view all the answers

<p>They can either depolarize or hyperpolarize the postsynaptic membrane. (C)</p> Signup and view all the answers

<p>It stops when action potentials cease arriving. (C)</p> Signup and view all the answers

<p>They are broken down by enzymes. (A)</p> Signup and view all the answers

<p>They store neurotransmitters until an action potential triggers their release. (B)</p> Signup and view all the answers

<p>Summed postsynaptic excitation or inhibition (D)</p> Signup and view all the answers

<p>Nicotinic receptors (A)</p> Signup and view all the answers

<p>Post-synaptic cell response (A)</p> Signup and view all the answers

<p>They trigger second messengers via G-protein–coupled receptors. (D)</p> Signup and view all the answers

<p>It inhibits contraction via muscarinic receptors. (D)</p> Signup and view all the answers

<p>Heart 2 received a chemical signal from Heart 1. (D)</p> Signup and view all the answers

<p>Direct influence on ion current. (A)</p> Signup and view all the answers

<p>Exocytosis from synaptic vesicles (D)</p> Signup and view all the answers

<p>Na+, K+, and Cl- (B)</p> Signup and view all the answers

<p>They trigger the opening of ion channels. (B)</p> Signup and view all the answers

<p>Myelin decreases the resistance of the membrane to ion flow, speeding up action potential conduction. (B)</p> Signup and view all the answers

<p>Saltatory conduction speeds up the transmission of action potentials by allowing them to &quot;jump&quot; between nodes of Ranvier. (D)</p> Signup and view all the answers

<p>Myelinated axons use a specialized mechanism to generate action potentials called saltatory conduction, while unmyelinated axons use continuous conduction. (D)</p> Signup and view all the answers

<p>Myelin sheaths act as insulators, preventing ion leakage and allowing faster propagation. (C)</p> Signup and view all the answers

<p>The refractory period reduces the permeability of sodium channels, preventing depolarization of the previously activated segment. (B)</p> Signup and view all the answers

<p>The axon hillock initiates action potential generation, similar to unmyelinated axons, but the action potential travels differently in myelinated axons. (D)</p> Signup and view all the answers

<p>The axon hillock has a high concentration of sodium channels, making it the primary site of action potential initiation. (B)</p> Signup and view all the answers

<p>The concentration gradient of these ions allows for the rapid diffusion of ions across the membrane at the nodes, enabling action potential propagation. (D)</p> Signup and view all the answers

<p>A larger axon diameter increases conduction speed by decreasing the internal resistance to ion flow. (D)</p> Signup and view all the answers

<p>The presence of myelin reduces the resistance to ion flow, allowing for faster action potential propagation. (D)</p> Signup and view all the answers

<p>Action potential propagation is continuous along the entire length of the axon. (C)</p> Signup and view all the answers

<p>To prevent the backpropagation of action potentials into the soma, ensuring unidirectional signal flow. (D)</p> Signup and view all the answers

<p>The initial depolarization causes a conformational change in sodium channels, opening them up to allow sodium influx. (D)</p> Signup and view all the answers

<p>Myelin significantly decreases the energy expenditure due to the reduced number of membrane regions that need to be repolarized during an action potential. (D)</p> Signup and view all the answers

<p>The opening of sodium channels is a positive feedback loop, leading to further depolarization and more sodium channel opening. (C)</p> Signup and view all the answers

<p>The current carries the depolarization signal along the axon membrane, initiating new action potentials in the subsequent segments. (C)</p> Signup and view all the answers

The process during an action potential where the membrane potential becomes more positive due to Na+ influx.

Channels that open when a threshold is reached, allowing Na+ ions to flow into the cell, leading to depolarization.

Phase where K+ channels open, allowing K+ to exit, causing repolarization of the membrane back to resting potential.

Restoration of the membrane potential to a negative value after depolarization due to K+ efflux.

The period after an action potential when a neuron cannot fire another action potential, ensuring one-way transmission.

A model describing how action potentials are generated in neurons through ion channel interactions and positive feedback.

A process where initial depolarization triggers more Na+ channels to open, accelerating the depolarization.

The process by which action potentials travel along an axon from the axon hillock to the terminals without losing strength.

The part of the neuron where action potentials are initiated due to a high concentration of Na+ channels.

Action potentials travel along unmyelinated axons, relying on a sequential opening of Na+ channels.

An axon covered with myelin sheath that allows faster action potential propagation through saltatory conduction.

A fast mode of action potential propagation in myelinated axons where impulses jump between nodes of Ranvier.

Layer of protein and lipid that prevents ion crossing the membrane, reducing current loss.

Gaps in myelin sheath where ion exchange occurs, allowing action potentials to jump between them.

The neuron that sends the signal in a synapse, releasing neurotransmitters.

The neuron that receives a signal in a synapse, responding to neurotransmitters.

A type of synapse where ions pass directly between cells, allowing for rapid communication.

A synapse where neurotransmitters are released from presynaptic to postsynaptic cells across a gap.

Ions flow rapidly between cells, creating current.

Neurotransmitters are released from vesicles into the synaptic cleft through exocytosis.

Action potentials cause Ca2+ to enter the presynaptic neuron, triggering neurotransmitter release.

Neurotransmitter binds to postsynaptic receptors, leading to depolarization or hyperpolarization.

Some neurotransmitters bind to receptors to act as messengers, leading to cellular responses.

A postsynaptic neuron can integrate signals from multiple presynaptic neurons for a combined effect.

Receptors that bind neurotransmitters and activate second messengers for cellular effects.

Process where neurotransmitters are released into the synaptic cleft after Ca2+ entry.

Neurotransmitters are cleared from synaptic cleft after action potentials stop.

A neurotransmitter that can stimulate or inhibit muscles depending on the receptor.

An ionotropic receptor type that is a Na+ channel, leading to muscle contraction.

A metabotropic receptor that can inhibit cardiac muscle contraction via G-proteins.

Ligand-gated ion channels that respond directly to neurotransmitter binding.

Receptors that affect post-synaptic cells via second messengers, causing complex responses.

Ions that trigger neurotransmitter release when they enter the cytoplasm of axon terminals.