AP Psychology Unit 1 Part 1

Biological Bases of Behavior Part 1

Hippocampus

A major structure in the temporal lobe of the brain that plays a critical role in learning, memory consolidation, and spatial navigation.

Frontal lobe

The front region of the cerebral cortex responsible for high-level executive functions, decision-making, planning, voluntary motor control, and speech production.

Temporal lobe

The lateral region of the cerebral cortex involved in processing auditory information, language comprehension, and memory formation.

Occipital lobe

The posterior region of the cerebral cortex primarily responsible for processing visual information, including recognition of shapes, colors, and movement.

Parietal lobe

The upper posterior region of the cerebral cortex that processes somatosensory information such as touch, temperature, pain, and spatial orientation.

Hypothalamus

A small structure located below the thalamus that regulates homeostatic processes such as body temperature, hunger, and thirst, and controls the release of hormones via the pituitary gland.

Thalamus

A central subcortical structure that serves as the primary relay station for routing sensory information—excluding smell—to the appropriate areas of the cerebral cortex.

Medulla

The lowest region of the brainstem that controls vital autonomic functions necessary for survival, such as heart rate, blood pressure, respiration, and reflexes like swallowing.

Midbrain

The uppermost section of the brainstem that facilitates visual and auditory reflexes, eye movement, and motor control.

Amygdala

An almond-shaped structure within the temporal lobe involved in processing emotional responses, particularly fear and threat detection, as well as emotional memory consolidation.

Motor cortex

A region of the frontal lobe in the brain that plans, controls, and executes voluntary muscle movement

Forebrain

What makes us human, Largest part of the brain, Made up of the Thalamus, Limbic System, and Cerebral Cortex.

Psychoactive Drugs

Chemical substances that change brain function and alter a person’s mood, perception, consciousness, or behavior

Evolutionary Psychology

The study of how evolution and natural selection influence behavior and mental processes.

Natural Selection

The process in which traits that help organisms survive and reproduce become more common over generations.

Mutation

A random change in DNA that can create new genetic traits.

Behavior Genetics

The study of how genes and environment influence behavior.

Environment

The surroundings and experiences that influence a person's development and behavior.

Heredity

The passing of genetic characteristics from parents to their children.

Genes

Units of DNA that contain instructions for traits and biological processes.

Genome

The complete set of genetic information of an organism.

Identical Twins

Twins who develop from one fertilized egg that splits and therefore have nearly identical DNA.

Fraternal Twins

Twins who develop from two different eggs fertilized by two different sperm, sharing about $50\%$ of their genes on average.

Interaction

The idea that genes and environment work together to influence behavior and development.

Heritability

A measure of how much variation in a trait within a population is associated with different genetic differences.

Epigenetics

The study of how environmental factors can influence whether certain genes are turned on or off without changing the DNA sequence itself.

Nervous System

A complex network made up of nerve cells (neurons) that communicate via chemical messengers called neurotransmitters to take in information, make decisions, and send commands to tissues.

Central Nervous System

The primary decision-making center of the body formed by the brain and the spinal cord.

Peripheral Nervous System

The subsystem responsible for gathering information and for transmitting decisions from the Central Nervous System to other body parts.

Nerves

Electrical cables formed from bundles of axons that link the Central Nervous System with the body's sensory receptors, muscles, and glands.

Sensory (Afferent) Neurons

Neurons that carry incoming sensory messages from the body's tissues and sensory receptors inward to the Central Nervous System.

Motor (Efferent) Neurons

Neurons that carry outgoing instructions from the Central Nervous System outward to the body's muscles and glands.

Interneurons

Neurons within the brain and spinal cord that process internal information between sensory inputs and motor outputs.

Reflex Arc

A neural pathway that demonstrates how sensory neurons, association neurons (interneurons), and motor neurons work together to produce an involuntary response.

Somatic Nervous System

The division of the peripheral nervous system that enables voluntary control of skeletal muscles.

Autonomic Nervous System

The division of the peripheral nervous system that controls glands and internal organ muscles.

Sympathetic Nervous System

The branch of the autonomic nervous system that arouses the body and expends energy, accelerating heartbeat, raising blood pressure, and slowing digestion.

Parasympathetic Nervous System

The branch of the autonomic nervous system that calms the body and conserves energy, producing the opposite effects of the sympathetic nervous system.

Neuron

A specialized nerve cell that serves as the basic building block of the nervous system.

Dendrites

Branching fibers of a neuron that receive and integrate incoming information.

Cell Body (Soma)

The life-support center of a neuron that houses the nucleus and DNA while manufacturing necessary cellular fuel.

Axon

The neuron extension that passes messages through its terminal branches to other neurons, muscles, or glands.

Myelin Sheath

A layer of fatty tissue segmentally encasing neuron fibers, acting as an insulator to vastly increase the speed of neural impulses.

Glial Cells

Non-neuronal cells in the nervous system that support, nourish, and protect neurons.

Resting Potential

The electrical state of an inactive neuron, maintaining a negative internal charge of roughly $-70\,mV$ relative to the outside.

Action Potential

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

Depolarization

The process during an action potential where a neuron's internal charge becomes less negative as positive ions rush inside.

Refractory Period

The brief cooldown phase following an action potential during which a neuron cannot fire another impulse without a stronger stimulus.

Threshold

The boundary level of physical energy or stimulation required to trigger a neural impulse.

All-Or-Nothing Response

A neuron's reaction principle of either firing an action potential at full strength or not firing at all.

Synapse

The microscopic junction or gap between the sending neuron's axon terminal and the receiving neuron's dendrite or cell body.

Neurotransmitter

Chemical messengers that travel across the synaptic gap between neurons to transmit signals.

Neurotransmitter Reuptake

The process where the sending (presynaptic) neuron reabsorbs leftover neurotransmitter molecules from the synaptic gap.

Endocrine System

The body's slow chemical communication system composed of glands that secrete hormones directly into the bloodstream.

Hormones

Chemical messengers produced by endocrine glands that travel through the bloodstream to regulate long-term bodily functions like stress, growth, and metabolism.

Adrenal Glands

Endocrine glands located above the kidneys that secrete epinephrine and norepinephrine to trigger the fight-or-flight response during emergencies.

Thyroid and Parathyroid Glands

Endocrine structures located in the neck; the thyroid controls metabolism, and the parathyroids regulate blood calcium levels.

Pituitary Gland

The endocrine system's master gland, situated beneath the hypothalamus, which regulates physical growth and controls other endocrine glands.

Psychoactive Drug

A chemical substance that alters perception, mood, consciousness, or behavior by modifying synaptic communication between neurons.

Substance Use Disorder

A condition characterized by continued, compulsive substance use despite significant health, social, or occupational disruption.

Tolerance

The neuroadaptative process in which the brain adjusts to a drug, requiring larger doses to achieve the desired effect.

Addiction

Compulsive craving and engagement in a substance or behavior despite severe negative consequences.

Withdrawal

The physical and psychological distress that follows stopping or reducing the intake of an addictive drug.

Depressants

Psychoactive drugs (such as alcohol, barbiturates, and opiates) that reduce neural activity, slow body functions, and impair self-awareness.

Stimulants

Psychoactive drugs (such as amphetamines, nicotine, cocaine, and ecstasy) that excite neural activity and speed up bodily functions.

Hallucinogens

Psychedelic drugs (such as LSD and marijuana/THC) that distort perceptions of time and evoke sensory images in the absence of sensory input.

Biological Psychology

The branch of psychology that studies how biological processes (genetics, hormones, brain structure) influence mental processes and behavior.

Biopsychosocial Approach

An integrated framework that analyzes human behavior through biological, psychological, and social-cultural factors.

Levels of Analysis

Differing, complementary viewpoints used to examine biological, psychological, or social-cultural aspects of a given phenomenon.

Plasticity

The brain's ability to modify its neural pathways and adapt structurally to environmental changes or injury.

Lesioning

The selective destruction or removal of a brain region to study its physiological function.

Electroencephalogram (EEG)

A neuroimaging technique that records electrical wave activity across the surface of the brain, frequently used in sleep research.

Magnetoencephalography (MEG)

A non-invasive technique that measures tiny magnetic fields produced by electrical currents in active brain neurons.

Computerized Tomography (CT)

A structural brain imaging technique using X-rays to detect tissue damage, tumors, or fractures.

Positron Emission Tomography (PET)

A functional brain scan that tracks radioactive tracer substances to display dynamic 3D visual patterns of metabolic activity.

Magnetic Resonance Imaging (MRI)

A non-invasive structural imaging method that uses magnetic fields and radio waves to generate high-resolution anatomical photos.

Functional Magnetic Resonance Imaging (fMRI)

A neuroimaging technique that measures blood oxygenation levels to detect real-time functional brain activity.

Brainstem

The core base structure of the brain that connects the cerebral cortex to the spinal cord.

Reticular Formation

A nerve network in the brainstem that filters incoming stimuli and regulates arousal, alertness, and attention.

Cerebellum

The structure at the rear of the brainstem that coordinates balance, fine motor timing, and language comprehension.

Limbic System

A neural structure array beneath the cerebral cortex that governs emotions, basic drives, and memory formation.

Cerebral Cortex

The outer layer of interconnected neural tissue across the brain lobes responsible for high-level information processing.

Neurogenesis

The biological process of generating new neurons within the brain.

Corpus Callosum

The broad band of axon fibers connecting the left and right cerebral hemispheres, facilitating interhemispheric communication.

Split Brain

A surgical condition where the corpus callosum is severed, isolating the left and right cerebral hemispheres.