unit one

Behavior geneticists

Professionals who explore genetic and environmental roots of human differences.

Adaptation

The process through which a species becomes fitted to the environment.

Mutation

A random error in gene replication that leads to a change.

Heredity

The transmission of genetic characteristics from parents to offspring.

Environment

Refers to nurture and everything non-genetic.

Chromosomes

Threadlike structures made of DNA that contain genes.

DNA

A complex molecule containing genetic information that makes up chromosomes.

Nervous system

A network of nerves and cells that transmit signals between different body parts.

Endocrine system

A system that produces hormones regulating bodily functions such as growth, metabolism, and mood.

Brain

The organ that processes information, controls actions, thoughts, and regulates body functions.

Peripheral nervous system

Nerves outside the brain and spinal cord that connect the CNS to the body.

Central nervous system

Consists of the brain and spinal cord.

Autonomic nervous system

Controls involuntary functions like heart rate, digestion, and breathing.

Somatic nervous system

Controls voluntary movements of skeletal muscles.

Spinal cord

A nerve bundle that transmits signals between the brain and body.

Enteric nervous system

Directly controls gastrointestinal tract, pancreas, and gallbladder.

Efferent neurons

Motor neurons that carry signals away from the central nervous system.

Afferent neurons

Sensory neurons that carry signals toward the central nervous system.

Reflexes

Automatic, rapid responses to stimuli, bypassing conscious brain activity.

Sympathetic nervous system

Part of the autonomic nervous system that triggers the fight/flight response.

Parasympathetic nervous system

Part of the autonomic nervous system responsible for rest and digest functions.

Excitatory neurotransmitters

Chemical messengers that rev up neurons.

Inhibitory neurotransmitters

Chemical messengers that calm neurons down.

Cell body (soma)

Part of a neuron that contains the nucleus and DNA.

Dendrites

Parts of a neuron that receive signals from other neurons.

Axon

The part of a neuron that carries signals from one end to another.

Axon terminals

Endings of an axon that send signals to the next neuron.

Schwann cells

Cells that produce myelin for the myelin sheath.

Nodes of Ranvier

Gaps between Schwann cells along the axon.

Glial cells

Support cells for the nervous system that provide protection and nourishment for neurons.

Action potential

The generation of electric impulses in a neuron.

Resting potential

The state of a neuron when it is not firing, having a slightly negative charge.

Threshold

The minimum stimulation needed to trigger a neural impulse.

All or nothing law

A principle stating that a neuron either fires completely or does not fire at all.

Refractory period

A brief pause between successive firings of a neuron.

Acetylcholine

A neurotransmitter that enables muscle action, learning, and memory.

Dopamine

A neurotransmitter that influences voluntary movement, learning, attention, and emotion.

Serotonin

A neurotransmitter that affects mood, hunger, sleep, and arousal.

Norepinephrine

A neurotransmitter that helps control alertness and arousal.

GABA

An inhibitory neurotransmitter that acts as a natural tranquilizer.

Glutamate

An excitatory neurotransmitter involved in memory.

Endorphins

Neurotransmitters that influence the perception of pain and pleasure.

Substance P

A neurotransmitter involved in the perception and signaling of pain.

Adrenaline

A hormone that prepares the body for emergencies and the fight/flight response.

Oxytocin

A hormone that facilitates lactation and improves social bonding.

Cortisol

A hormone that helps maintain homeostasis, often referred to as the stress hormone.

Psychoactive drugs

Chemical substances that alter perceptions and moods.

Substance use disorder

Characterized by continued substance craving and usage despite negative consequences.

Neurotransmitters

Chemical messengers of the nervous system.

Agonists

Substances that increase or mimic neurotransmitter action.

Antagonists

Substances that block receptor cells and inhibit neurotransmitter action.

Reuptake inhibitors

Substances that block the reuptake process, prolonging the effect of neurotransmitters.

Hallucinogens

Drugs that cause false sensory hallucinations and impair memory.

Depressants

Substances that increase relaxation and pain relief, often decreasing mood and arousal.

Stimulants

Substances that increase energy levels and decrease appetite, often providing brief euphoria.

Addiction

A complex condition characterized by compulsive drug use despite harmful consequences.

Tolerance

Diminished psychoactive effects experienced after repeated use of a substance.

Withdrawal

Painful symptoms experienced as the body readjusts to the absence of a drug.

Biological psychologists

Psychologists who focus on how the body and brain enable emotions, memory, and sensory experiences.

Neuroplasticity

The brain's ability to change, build, and reorganize after injury or damage.

Neurogenesis

The process of producing new neurons in the brain.

Electroencephalogram (EEG)

A test that measures electrical activity in neurons using electrodes placed on the scalp.

Magnetoencephalography (MEG)

A technique that records magnetic fields produced by the brain's natural electrical currents.

Computed Tomography (CT)

An imaging method that generates images of the brain to locate damage using x-rays.

Positron Emission Tomography (PET)

An imaging test that tracks where radioactive glucose goes during tasks.

Magnetic Resonance Imaging (MRI)

A technique using magnetic fields to create detailed images of brain structure.

Functional MRI (fMRI)

An imaging technique that measures brain activity by detecting blood flow changes.

Hindbrain

The part of the brain that consists of structures involved in survival functions.

Midbrain

The portion of the brain involved in movement and sensation, facilitating communication between hindbrain and forebrain.

Forebrain

The largest and most complex part of the brain, involved in cognitive functions like memory, emotion, and reasoning.

Reticular formation

A nerve network important for controlling arousal.

Medulla

The base of the brainstem that controls breathing and heart rate.

Pons

The part of the brain that connects hindbrain, midbrain, and forebrain, involved in respiration and REM sleep.

Thalamus

The brain structure that directs messages and transmits responses to sensory areas and cerebellum/medulla.

Cerebellum

The brain region responsible for movement, balance, and sensory input processing.

Limbic system

A neural system associated with emotions and drives.

Amygdala

Brain region associated with survival emotions like fear and aggression.

Hippocampus

Brain structure involved in processing and storing explicit memories.

Hypothalamus

Brain region involved in regulating eating, drinking, body temperature, and emotions.

Corpus callosum

The structure that connects the left and right hemispheres of the brain.

Pituitary gland

Endocrine gland controlled by the hypothalamus that releases hormones.

Pineal gland

Brain gland that produces melatonin and regulates sleep cycles.

Cerebral cortex

The outer layer of interconnected neural cells covering the cerebral hemispheres.

Parietal lobe

The part of the brain that receives sensory input for touch and is located at the top of the head.

Frontal lobe

The brain region involved in executive functions, located behind the forehead.

Motor cortex

The area of the brain that controls voluntary muscle movement.

Broca's area

Region of the frontal lobe that controls the muscles involved in speech production.

Broca's aphasia

A condition resulting from damage to Broca's area, causing speech fluency issues.

Temporal lobe

The area of the brain located above the ears, involved in auditory processing and memory.

Wernicke's area

Brain region involved in language comprehension.

Auditory cortex

Brain region responsible for the organization and processing of auditory information.

Occipital lobes

Regions at the back of the head involved in processing visual information.

Visual cortex

Brain area that processes visual stimuli and images.

Association areas

Cortex areas involved in higher mental functions, such as learning, memory, and thinking.

Consciousness

Subjective awareness of ourselves and our environment.

Preconscious

Thoughts and feelings that are not currently in awareness but can be brought to consciousness.

Unconscious

Mental processes that are outside of conscious awareness.

Selective attention

The focusing of conscious awareness on a particular stimulus.

Cocktail party effect

The phenomenon of hearing one's name in a crowded room.

Dual processing

The mind's ability to process information along two different tracks.