AP Psychological- Neurotransmitters/Neurons

Neuron

A specialized cell that transmits nerve impulses throughout the body, playing a key role in the nervous system.

Dendrite

The branching extensions of a neuron that receive messages from other neurons and transmit them toward the cell body.

Soma

The cell body of a neuron, containing the nucleus and organelles, that integrates incoming signals and generates outgoing impulses.

Axon

A long, slender projection of a neuron that conducts electrical impulses away from the cell body to other neurons or muscles.

Myeline Sheath

A protective layer of fatty tissue that surrounds the axon of some neurons, enabling faster transmission of electrical signals.

Axon Terminal

The endpoint of an axon where neurotransmitters are released to communicate with neighboring neurons or target cells.

Terminal Buttons

Small structures at the end of axon terminals that contain neurotransmitters, facilitating communication between neurons.

Sensory Neurons (Afferent)

Nerve cells that carry sensory information from the body's sensory receptors to the central nervous system.

Motor Neurons (efferent)

Nerve cells that transmit signals from the central nervous system to muscles or glands, enabling movement and response.

Action Potential

A brief electrical charge that travels down an axon, resulting from the movement of ions in and out of the neuron, triggering neurotransmitter release.

Threshold

The level of stimulation required to trigger an action potential in a neuron, essential for transmitting signals.

Terminal Branches

The endpoints of axons that release neurotransmitters into the synapse, facilitating communication between neurons.

Refractory Period

The time following an action potential during which a neuron is unable to fire another action potential due to the resetting of ion channels.

Resting Potential

The electrical charge difference across the neuronal membrane when it is not actively transmitting an action potential, typically around -70 mV.

Receptor Sites

Locations on the postsynaptic membrane where neurotransmitters bind, initiating a response in the receiving neuron.

All or none principle

The principle stating that a neuron either fires an action potential at full strength or does not fire at all, regardless of the strength of the stimulus.

Synapse

The junction between two neurons where neurotransmitters are released and received, allowing for communication between them.

Neurotransmitter

Chemical messengers that transmit signals across the synapse between neurons. They bind to receptor sites to elicit a response in the receiving neuron.

Reuptake

The process by which neurotransmitters are reabsorbed by the presynaptic neuron after transmitting a signal across the synapse, thereby terminating the neurotransmitter's action.

Excitatory Effect

Increases the likelihood that a neuron will fire an action potential by depolarizing the postsynaptic membrane.

Inhibitory Effect

Decreases the likelihood that a neuron will fire an action potential by hyperpolarizing the postsynaptic membrane.

Acetycholine

A neurotransmitter involved in motor control, memory, and learning, known for its role in communication between nerves and muscles.

Dopamine

A neurotransmitter associated with pleasure, reward, and motor function, playing a key role in mood regulation and the brain's reward system.

Serotonin

A neurotransmitter that contributes to well-being and happiness, regulating mood, sleep, and appetite.

Endorphins

Neurotransmitters that act as natural pain relievers and mood enhancers, often released during exercise, stress, or pain.

Glutamate

An amino acid and neurotransmitter involved in learning and memory, playing a crucial role in synaptic plasticity.

GABA

A neurotransmitter that inhibits brain activity, promoting relaxation and reducing anxiety. It plays a crucial role in regulating neural excitability throughout the nervous system.

Norepinephrine

A neurotransmitter involved in the body’s stress response, affecting attention, focus, and arousal. It plays a key role in the fight-or-flight response.

Substance P

A neuropeptide that functions as a neurotransmitter and is involved in the transmission of pain signals and responses to stress.

Antagonist

A substance that blocks or inhibits the action of a neurotransmitter by binding to its receptor without triggering a response.

Agonist

A substance that mimics or enhances the action of a neurotransmitter by binding to its receptor and triggering a response.