Chapter 48 Neurons and Synapses

A set of 60 flashcards covering vocabulary and key concepts related to neurons, synapses, and neuronal signaling.

Neuron

A nerve cell that uses electricity and chemicals for communication.

Synapse

The small gap where neurotransmitters are produced and cross between neurons.

Axon

The part of a neuron that transmits signals away from the cell body.

Dendrites

Extensions of a neuron that receive signals from other nerve cells.

Central Nervous System (CNS)

The part of the nervous system that includes the brain and spinal cord.

Peripheral Nervous System (PNS)

The part of the nervous system that connects the CNS to limbs and organs.

Sensory Neurons

Neurons that collect information from sensory systems.

Interneuron

A neuron that processes information within the CNS.

Motor Neurons

Neurons that activate muscle cells.

Neurotransmitter

Chemicals that transmit signals across a synapse.

Resting Potential

The state of a neuron when it is not sending a signal, typically -70 mV.

Action Potential

A rapid rise and fall in membrane voltage during a neuronal signal.

Membrane Potential

The voltage difference across a neuron's membrane.

Sodium-Potassium Pump

A protein that moves sodium out and potassium into a neuron against their gradients.

Depolarization

A decrease in membrane potential making the inside of the cell less negative.

Hyperpolarization

An increase in membrane potential making the inside of the cell more negative.

Graded Potentials

Variations in membrane potential that can lead to action potentials.

Refractory Period

The time after an action potential when a neuron cannot fire again.

Myelin Sheath

A fatty layer that insulates axons and speeds up neuronal transmission.

Nodes of Ranvier

Gaps in the myelin sheath where action potentials are regenerated.

Saltatory Conduction

The process by which action potentials jump between Nodes of Ranvier.

Ligand-Gated Ion Channels

Ion channels that open in response to neurotransmitters.

EPSP (Excitatory Postsynaptic Potential)

A postsynaptic potential that makes the neuron more likely to fire an action potential.

IPSP (Inhibitory Postsynaptic Potential)

A postsynaptic potential that makes the neuron less likely to fire an action potential.

Temporal Summation

The process where multiple EPSPs in rapid succession can trigger an action potential.

Spatial Summation

The process where EPSPs from different synapses can trigger an action potential.

Neurotransmitter Groups

Categories of neurotransmitters including acetylcholine and biogenic amines.

Acetylcholine

A common neurotransmitter involved in muscle activation and memory.

Biogenic Amines

A group of neurotransmitters including dopamine and serotonin.

Amino Acids

A group of neurotransmitters including glutamate and GABA.

Neuropeptides

A group of neurotransmitters that includes endorphins.

Gases as Neurotransmitters

Includes nitric oxide (NO) and carbon monoxide (CO), which signal in the nervous system.

Synaptic Vesicles

Membrane-bound structures that store neurotransmitters in presynaptic neurons.

Presynaptic Cell

The neuron that releases neurotransmitters into the synapse.

Postsynaptic Cell

The neuron, muscle, or gland that receives signals at the synapse.

Voltage Gradient

A measure of the electrical gradient across the neuron's membrane.

Ion Channels

Protein structures in the membrane that allow ions to flow in and out of the neuron.

K+ (Potassium Ion)

An ion that is usually high inside a neuron, important for restoring resting potential.

Na+ (Sodium Ion)

An ion that is usually high outside a neuron, critical for depolarization.

Neural Communication

The process of signal transmission between neurons via electrical impulses and neurotransmitters.

Glia

Support cells in the nervous system that assist neurons.

Oligodendrocytes

Glial cells in the CNS that form myelin sheaths.

Schwann Cells

Glial cells in the PNS that form myelin sheaths.

Neural Integration

The process by which sensory input is processed and responded to by the nervous system.

Neuronal Signaling

The transmission of information through action potentials and neurotransmitter release.

Threshold Potential

The critical level to which a membrane must be depolarized to initiate an action potential.

Action Potential Sequence

Resting → Depolarization → Peak → Repolarization → Undershoot.

Motor Output

The response generated by motor neurons that activate muscles.

Sensory Input

Information received from sensory organs like eyes and ears.

Integration Center

The brain or spinal cord where sensory information is processed.

Signal Transmission

The process of sending messages from one neuron to the next.

Chemical Synapse

A type of synapse that uses neurotransmitters for communication.