Ap psychology unit 2

Neuron

A nerve cell; the basic building block of the nervous system.

Cell body (soma)

The part of a neuron that contains the nucleus and keeps the cell alive.

Dendrite

Branch-like parts of a neuron that receive messages from other cells.

Axon

The long part of a neuron that carries messages away from the cell body.

Myelin sheath

A fatty covering around the axon that speeds up neural signals.

Action potential

A brief electrical signal that travels down a neuron's axon.

Synapse

The junction where one neuron communicates with another cell.

Glial cells

Cells that support, protect, nourish, and help neurons.

Threshold

The minimum level of stimulation needed to trigger an action potential.

Refractory period

A short period after an action potential when a neuron cannot fire again immediately.

All-or-nothing principle

A neuron either fires completely or does not fire at all.

Neurotransmitter

A chemical messenger that carries signals across a synapse.

Reuptake inhibitor

A substance that blocks neurotransmitters from being reabsorbed by the sending neuron.

Endorphins

Natural neurotransmitters that reduce pain and can produce feelings of pleasure.

Agonist

A substance that increases or mimics a neurotransmitter's effects.

Antagonist

A substance that blocks or decreases a neurotransmitter's effects.

Depolarization

The change in a neuron's electrical charge that helps trigger an action potential.

Polarization

The state when a neuron has different electrical charges inside and outside its membrane.

Synaptic cleft

The tiny gap between neurons where neurotransmitters travel.

Endocrine system

The body's system of glands that releases hormones into the bloodstream.

Hormones

Chemical messengers released by endocrine glands that affect body functions and behavior.

Biological psychology

The study of how biological processes influence behavior and mental processes.

Levels of analysis

Different perspectives used to understand behavior, such as biological, psychological, and social-cultural.

Neuroplasticity

The brain's ability to change and reorganize itself through experience, learning, or injury.

Lesion

Tissue damage in the brain; studying lesions can show what certain brain areas do.

EEG (electroencephalogram)

A technique that records the brain's electrical activity using electrodes on the scalp.

MEG (magnetoencephalography)

A technique that measures magnetic fields produced by the brain's electrical activity.

CT (computed tomography)

A series of X-rays used to create images of brain structure.

PET (positron emission tomography)

A brain scan that shows activity by tracking a radioactive form of glucose.

MRI (magnetic resonance imaging)

A scan that uses magnetic fields and radio waves to create detailed images of brain structure.

fMRI (functional MRI)

A scan that shows brain activity by measuring changes in blood flow.

Selectively permeable

Describes a membrane that allows some substances to pass through while blocking others.

Serotonin

A neurotransmitter involved in mood, sleep, and appetite.

Norepinephrine

A neurotransmitter involved in alertness, arousal, and attention.

GABA

The brain's major inhibitory neurotransmitter; it slows neural activity.

Inhibitory

Decreases the likelihood that a neuron will fire.

Excitatory

Increases the likelihood that a neuron will fire.

Acetylcholine (ACh)

A neurotransmitter involved in muscle movement, learning, and memory.

Neural networks

Groups of interconnected neurons that work together to process information.

Glutamate

The brain's major excitatory neurotransmitter; important for learning and memory.

Dopamine

A neurotransmitter involved in movement, motivation, reward, and learning.

Ions

Electrically charged particles that move across neuron membranes and help create neural signals.

Substance P

A neurotransmitter involved in transmitting pain signals.

Pituitary gland

The endocrine system's "master gland"; it influences growth and controls other endocrine glands.

Curare

A drug that blocks acetylcholine receptors and can cause muscle paralysis.

Multiple sclerosis (MS)

A disease in which the immune system damages the myelin sheath, disrupting neural communication.

DNA

A molecule containing the genetic instructions for an organism's development and functioning.

Chromosomes

Threadlike structures made of DNA that contain genes.

Adrenal glands

Glands located above the kidneys that release stress hormones such as epinephrine and norepinephrine.

Heritability

The proportion of differences among individuals in a group that can be attributed to genetic differences.

Resting potential

The neuron's stable, negatively charged state when it is not firing.

Nature-nurture issue

The debate about how much genes and environment influence behavior and traits.

Interaction

The way genes and environmental factors work together to influence behavior and development.

Peripheral Nervous System (PNS)

The nerves outside the brain and spinal cord that connect the CNS to the rest of the body.

Genetics

The study of heredity and how traits are passed from parents to offspring.

Molecular genetics

The study of the structure and function of genes and how specific genes influence traits and behavior.

Biopsychosocial approach

An approach that explains behavior using biological, psychological, and social-cultural factors.

Botox

A substance that blocks acetylcholine release, temporarily preventing muscle contractions.

Evolutionary psychology

The study of how natural selection may have shaped behavior and mental processes.