At a chemical synapse, the arrival of an action potential at the axon terminal triggers the influx of which ion, leading to the release of neurotransmitter vesicles?
Explanation
Synaptic transmission converts an electrical signal (action potential) into a chemical signal (neurotransmitter). This conversion is triggered when the action potential opens voltage-gated calcium channels at the axon terminal. The resulting influx of calcium causes vesicles filled with neurotransmitter to fuse with the presynaptic membrane and release their contents into the synaptic cleft.
Other questions
What are the two major anatomical divisions of the nervous system?
What is the term for a localized collection of neuron cell bodies within the Central Nervous System (CNS)?
A bundle of axons found within the Peripheral Nervous System (PNS) is referred to as what?
Which functional division of the nervous system is primarily responsible for the involuntary control of the body to maintain homeostasis?
Which type of glial cell is responsible for insulating axons with myelin within the central nervous system (CNS)?
What is the name of the glial cell type that provides myelin insulation for axons in the peripheral nervous system (PNS)?
What is the value, in millivolts (mV), that is most commonly used to describe the resting membrane potential of a neuron?
An action potential is initiated when the neuronal membrane depolarizes to a specific voltage known as the threshold. What is the typical value of this threshold in millivolts (mV)?
The depolarization phase of an action potential, where the membrane potential rapidly rises towards a positive value, is caused by the influx of which ion?
What is the term for the period following an action potential during which a new action potential cannot be initiated, regardless of the stimulus strength, due to the inactivation of voltage-gated sodium channels?
The nicotinic receptor for acetylcholine is an example of what type of receptor, which functions as a ligand-gated ion channel?
Which amino acid neurotransmitter is considered excitatory in the adult nervous system because its receptors cause depolarization of the postsynaptic cell?
A neuron that possesses one axon and two or more dendrites is classified by its shape as what type of neuron?
Which type of glial cell functions as a CNS-resident macrophage, performing immune surveillance and phagocytosis?
What is the term for the method of action potential propagation along a myelinated axon, where the electrical signal appears to jump from one node of Ranvier to the next?
A graded potential in a postsynaptic neuron that causes hyperpolarization, making an action potential less likely to occur, is known as what?
What is the name of the special region of a neuron where the axon emerges from the cell body?
The repolarization phase of the action potential, where the membrane potential returns toward its resting value, is primarily caused by the efflux (outflow) of which ion?
The enteric nervous system (ENS), which operates largely independently of the CNS, is responsible for controlling which organ system?
What chemical is the basis of the cholinergic neurotransmitter system?
How many distinct types of glial cells are found within the Central Nervous System (CNS)?
An action potential involves a membrane voltage change from a resting potential of -70 mV to a peak depolarization value of what?
What lipid-rich substance is primarily responsible for giving white matter its characteristic color?
What type of receptor is characterized by a complex of proteins that, upon binding a neurotransmitter, initiates metabolic changes inside the cell through a G protein and a second messenger?
The physiological barrier that restricts what can cross from circulating blood into the CNS, known as the blood-brain barrier (BBB), is maintained by which glial cell?
What is the name for a type of ion channel that is randomly gated, opening and closing without a specific event, thereby contributing to the resting membrane potential?
What is the term for the process where multiple graded potentials occurring at different locations on a neuron are added together?
What is the primary function of the sodium/potassium pump in a neuron?
Which structural classification of neuron, commonly found in the olfactory epithelium and retina, is characterized by two processes extending from opposite ends of the cell body?
The biogenic amine neurotransmitter serotonin is enzymatically synthesized from which amino acid?
The period of hyperpolarization, or the 'undershoot,' following an action potential is caused by the slightly delayed closing of which ion channels?
In the sensory pathway for a stimulus like water temperature, where does conscious perception first occur?
What is the primary function of satellite cells, a type of glial cell in the Peripheral Nervous System?
In a metabotropic receptor pathway, what are the two common examples of second messengers that are generated to cause metabolic changes within the cell?
According to the text, which of the following is NOT one of the three basic functions of the nervous system?
What is the anatomical term for the gaps in the myelin sheath that are crucial for saltatory conduction?
In unipolar sensory neurons, a graded potential that develops in the dendrites and influences the generation of an action potential in the axon is referred to as what?
Which glial cell type is responsible for filtering blood to produce cerebrospinal fluid (CSF)?
The principle that an action potential either occurs completely or not at all is known as what?
The axons projecting from the retina into the brain are referred to as the optic nerve when they leave the eye. What are they called after they cross the optic chiasm inside the cranium?
A voltage-gated sodium channel possesses two distinct gates that control ion flow. What are these two gates called?
Dopamine, norepinephrine, and epinephrine are all biogenic amine neurotransmitters that are enzymatically made from which amino acid?
In the peripheral nervous system (PNS), how many Schwann cells are required to myelinate a single segment of an axon?
What type of ion channel opens in response to a physical distortion of the cell membrane, such as pressure applied to the skin?
Which functional division of the nervous system is characterized by conscious perception and voluntary motor responses?
Based on their function and characteristics, unipolar cells found in humans are exclusively what type of neuron?
The voltage-gated potassium (K+) channel has one gate that is sensitive to a specific membrane voltage. At approximately what voltage does this channel begin to open, albeit with a slight delay?
What is the term for the process by which amino acid neurotransmitters are cleared from the synaptic cleft by being transported back into the presynaptic element or a neighboring glial cell?
What are the three fundamental functions of the nervous system?