AP Psych Unit 1.1-1.5

Nature

Genetics and DNA

Evolutionary Perspective

how the natural selection of traits has promoted the survival of genes

Natural selection

A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.

environment

The sum of your surroundings

Heredity

Passing of traits from parents to offspring

Genes

DNA segments that serve as the key functional units in hereditary transmission.

Genome

all of an organism's genetic material

Nurture

environmental influences, behavior, childhood, psychological development

Eugenics

Movement that promoted selective breeding to improve the human population by encouraging reproduction among those with "desirable" hereditary traits and discouraging it among those with "undesirable" traits.

Twin studies

Research method that compares identical (monozygotic) and fraternal (dizygotic) twins to determine the relative contributions of genetics and environment (nature vs. nurture) to specific traits or behaviors.

adoption studies

Natural experiments showing if traits come from genes (biological parents) or environment (adoptive parents).

identical (monozygotic) twins

Individuals that develop from a single fertilized egg that splits in two, creating two genetically identical individuals. More behaviorally similar than fraternal twins. Share 100% of their genes.

Fraternal (Dizygotic) twins

Individuals who develop from separate fertilized eggs; genetically no closer than ordinary siblings, but share a prenatal environment. Share 50% of their genes.

Epigenetics

How our environment can influence gene expression without changing the DNA itself.

Nervous system

Ultimate network of communication. Responsible for transmitting information between the brain and the body.

Central nervous system

Made up of the brain and spine. Acts as the command center, processing information and sending instructions throughout the body.

nerves

Bundled axons that form neural "cables" connecting the central nervous system with the muscles, glands and sense organs. The three types are: sensory neurons, motor neurons, and interneurons.

reflex

Involuntary, innate responses to specific stimuli that occur without conscious thought.

autonomic nervous system

Controls involuntary actions like breathing (blinking is a VOLUNTARY action).

sympathetic nervous system

Stimulates and mobilizes energy. Involved in the fight or flight response.

peripheral nervous system

Made up of all other nerves. Connects to the rest of the body. Contains two other components: somatic nervous system, and autonomic nervous system, which contains the sympathetic nervous system and the parasympathetic nervous system.

somatic nervous system

Controls voluntary movements of skeletal muscles.

parasympathetic nervous system

Stores energy. Involved in the rest and digest state.

Neurons

Basic building blocks of the nervous system, specialized cells that transmit information through electrical and chemical signals. There are approximately 86 billion neurons in the human central nervous system. Composed of: Dendrites, cell body (soma), axon, myelin sheath, synapse, synaptic vesicles, and terminal buttons.

Cell body

Takes the information in.

dendrites

Receivers. Cannot touch each other.

Axon

Passes messages away from the cell body.

Myelin

Covers the axon. Helps signals move faster.

Synapse

Entire junction where neurons communicate.

Glial cells

Supporting cells of the nervous system that nourish, insulate, and protect neurons.

Reflex arch

Neural pathway that controls a reflex action, an automatic, involuntary response to a stimulus that happens too fast for conscious thought.

Sensory nuerons

Carry information from the body to the brain and spinal cord.

motor nuerons

Transmit signals from the brain and spinal cord to the body.

interneurons

Connect sensory and motor neurons within the central nervous system to process information.

Action potential

A brief electrical charge that travels down the axon.

all or nothing principle

A neuron either fires or it doesn't—there's no halfway

depolarization

When a neuron's charge becomes less negative, leading to firing.

Reuptake

the process where a neuron reabsorbs a chemical messenger (neurotransmitter) from the space between two nerve cells after it has delivered its message

Multiple Sclerosis

The myelin sheath is damaged, slowing down or blocking signals

Neurotransmitters

Chemical messengers that transmitsignals across the synapse

excitatory neurotransmitters

Encourage neurons to fire

Dopamine

Involved in reward and motivation

Norepinephrine

Arouses alertness and energy

GABA

An inhibitory neurotransmitter in the brain, calms you down.

Substance P

a neurotransmitter involved in transmitting pain signals to the brain

Hormones

Chemical messengers that travel through the bloodstream and affect behavior and mood

Leptin

Regulates hunger and fat storage

Melatonin

Regulates sleep-wake cycles

psychoactive drugs

Substances that affect brain activity and lead to changes in perception, mood, or consciousness.

substance use disorder

When drug use becomes uncontrollable and interferes with daily life

Antagonist

Drugs that block neurotransmitter activity

Stimulants

Speed up body functions and enhance energy

Caffeine

Stimulant- Blocks the chemical adenosine which causes drowsiness. Enhances cognitive function, increases anxiety, and causes dependency.

Cocaine

Stimulant- Speeds up your brain and body making you feel more happy or energetic.

Methamphetamine

Stimulant- Makes people very awake but damages brain cells and causes a fast heartbeat.

ecstasy

extreme happiness

Opioids

depressant, treat pain

Heroin

opioid, produces morphine

Addiction

A compulsive craving for a substance despiteharmful consequences

Refractory period

After firing, the neuron needs time to reset before firing again

resting potential

The state of a neuron when it's ready to fire but hasn't yet

threshold

the minimum level of stimulation needed to trigger a response, whether it's a neural impulse or a sensory perception

myasthenia gravis

An autoimmune disorder where acetylcholine receptors are attacked, leading to muscle weakness

inhibitory neurotransmitters

prevent neurons from firing

Serotonin

Regulates mood and sleep

Glutamate

Excitement and memory

Endorphins

Natural pain killers

Acetylcholine

muscle movement and memory

endocrine system

A slower communication system that uses hormones instead of neurotransmitters

Adrenaline

Increases heart rate and energy(fight-or-flight)

Ghrelin

stimulates hunger

Oxytocin

Influences bonding and socialbehaviors

Agonist

Drugs that mimic neurotransmitters or enhance their action

Reuptake inhibitors

Drugs that prevent the reabsorption of neurotransmitters ,increasing their activity

Depressants

Slow down body functions andneural activity

Alcohol

Depressant

Hallucinogens

Alter perception and can cause visual or auditory hallucinations

Marijuana

Hallucinogen: Effects how your brain sends messages, affects memory attention and coordination.

LSD

Hallucinogen

Tolerance

The need to take more of a drug to achieve the same effect.

Withdrawal

Physical and psychological symptoms when stopping the drug

Brain plasticity

The capacity for the brain to alter its structure and function.

EEG

electroencephalogram; an amplified recording of the waves of electrical activity that sweep across the brain's surface. These waves are measured by electrodes placed on the scalp

MEG

Magnetoencephalography, a non-invasive neuro imaging technique that measures the magnetic fields produced by electrical activity in the brain

MRI

Magnetic resonance imaging

A technique that uses magnetic fields and radio waves to produce computer-generated images that distinguish among different types of soft tissue; allows us to see structures within the brain

CT

computed tomography

PET

a visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a given task

fMRI

A technique for revealing blood flow and, therefore, brain activity by comparing successive MRI scans.

Lesions

removal or destruction of part of the brain

Brain stem

Connects the brain and spinal cord, basic life functions

Hindbrain

medulla, pons, cerebellum

midbrain

A small part of the brain above the pons that integrates sensory information and relays it upward.

forbrain

Collection of upper-level brain structures, including the thalamus, hypothalamus, and limbic system.

medulla oblongata

Manages vital functions like breathing and heart rate—without it, you wouldn't survive

Reticular Activating System (RAS)

controls sleep/wake cycles, alertness, and voluntary movements

Cerebellum

Balance and coordination

cerebral cortex

The brain's outermost layer, responsible for higher-level thinking and complex tasks

limbic system

emotion and memory

Thalamus

The brain's "relay station," it sends sensory information to the right areas of the brain for processing.

Hypothalamus

Regulates basic drives like hunger, thirst, and body temperature—keeping you in balance