AP Psych - Unit 1

Heredity

The transmission of traits from parents to offspring

Genetic Predisposition

A tendency for certain traits to be inherited from parents in our genes.

Evolutionary Perspective

School of thought that analyzes gradual changes in a population over many generations and examines the role of natural selection.

Natural Selection

Process by which environmental factors eliminate individuals who cannot adapt. Survivors reproduce and pass on adaptive traits (“survival of the fittest”)

Eugenics

A social/political philosophy that attempts to improve genetic quality through selective breeding. Historically misused to justify racism and genocide.

Neuron

Cellular units of the nervous system (nerve cells).

Sensory Neuron

Receives information from the environment (afferent nerve); sends info to the brain.

Motor Neuron

Connects to muscle fibers (efferent nerve); receives info from the brain.

Interneuron

Connector neuron, often found in the spinal cord.

Reflex

Automatic response to a stimulus involving sensory neurons, interneurons, and motor neurons before the brain registers it.

Glial Cells

Support neurons by providing nutrients, insulating myelin, helping connections, and cleaning waste; linked to intelligence.

Dendrites

Finger-like extensions of the cell body that receive messages.

Cell Body (Soma)

Contains the nucleus and controls action potential firing.

Axon

Extension of a nerve cell that carries electrical signals (action potential).

Myelin Sheathe

Insulating layer around axons that increases speed of transmission. Breakdown leads to multiple sclerosis.

Terminal Buttons/Vesicles

Tiny sacs that store and discharge neurotransmitters across the synapse.

Neural Transmission

Sending information from one neuron to another via neurotransmitters at the synapse.

Action Potential

Neural firing; an electrical charge change in the axon caused by depolarization (mixing sodium and potassium ions).

Resting Potential

State of a neuron at rest, awaiting signals.

All-or-Nothing Principle

A neuron either fires an action potential or doesn’t — no partial firing.

Reuptake

Reabsorption of neurotransmitters by the sending neuron after transmission.

Refractory Period

Inactivity after firing, during which the neuron can’t respond.

Neurotransmitters

Chemicals released into synapses that transmit information to other neurons.

Excitatory

Increase likelihood of firing

Inhibitory

Decrease likelihood of firing.

Acetylcholine (Ach)

Enables muscle movement, memory, learning. Deteriorates in Alzheimer’s disease.

Dopamine

Influences movement, reward, and emotion. Too little → Parkinson’s. Too much → schizophrenia, anxiety, or addiction.

Serotonin

Affects mood, hunger, sleep. Undersupply linked to depression and anxiety. Known as the “feel-good” neurotransmitter.

Norepinephrine

Increases alertness and arousal; similar to epinephrine.

GABA (gamma-aminobutyric acid)

Primary inhibitory neurotransmitter; undersupply linked to seizures.

Glutamate

Primary excitatory neurotransmitter; oversupply may cause migraines/seizures.

Endorphins

Produced during exercise or trauma; reduce pain and create euphoria.

Substance P

Neurotransmitter that causes the feeling of pain.

Hormones

Slow-moving chemical messengers in the bloodstream, tissues, and organs.

Adrenaline (Epinephrine)

Released in fight-or-flight; increases sympathetic nervous system arousal.

Leptin

Communicates body fat levels to hypothalamus; regulates food intake.

Ghrelin

Secreted in the stomach; stimulates appetite and growth hormone.

Melatonin

Regulates circadian rhythm.

Oxytocin

Stimulates uterine contractions, bonding, nurturing, sexual pleasure.

Agonist

Drug/chemical that binds to receptors and stimulates them (e.g. morphine)

Antagonist

Drug/chemical that binds to receptors but blocks neurotransmitter action (e.g., antipsychotics).

Reuptake Inhibitors

Drugs that prevent neurotransmitter reabsorption, prolonging effects.

Tolerance

Diminished drug effect; more required for same result.