AP PSYCH UNIT ONE

Neuron: A nerve cell that transmits electrical and chemical signals throughout the nervous system.

Glial Cells: Supportive cells in the nervous system that provide structural, nutritional, and metabolic support to neurons.

Dendrites: Branch-like extensions of a neuron that receive signals from other neurons.

Cell Body (Soma): The central part of a neuron containing the nucleus and essential organelles.

Axon: A long, slender projection of a neuron that conducts electrical impulses away from the cell body.

Myelin Sheath: A fatty layer encasing the axon of many neurons, which speeds up neural transmission.

Terminal Buttons (End Buttons, Axon Terminal, Terminal Branches of Axon, Synaptic Knobs): The small swellings at the end of an axon that release neurotransmitters into the synapse.

Neurotransmitters: Chemical messengers released by neurons that transmit signals across a synapse to another neuron or cell.

Synapse: The junction between two neurons where neurotransmitters are released and received.

Receptor Sites: Specialized areas on the surface of a neuron or other cell where neurotransmitters bind and elicit a response.

Threshold: The minimum level of stimulation required to trigger an action potential in a neuron.

Action Potential: A rapid, all-or-nothing electrical signal that travels along the axon of a neuron.

All-or-None Principle: The principle stating that a neuron either fires an action potential at full strength or does not fire at all.

Neural Firing: The process by which a neuron generates and transmits an action potential.

Excitatory Neurotransmitters: Chemicals that increase the likelihood of a neuron firing an action potential.

Inhibitory Neurotransmitters: Chemicals that decrease the likelihood of a neuron firing an action potential.

Acetylcholine: A neurotransmitter involved in muscle contraction and cognitive functions like memory.

Dopamine: A neurotransmitter associated with pleasure, reward, and motor control.

Endorphins: Neurotransmitters that act as natural painkillers and mood enhancers.

Serotonin: A neurotransmitter that regulates mood, sleep, and appetite.

Afferent Neurons (Sensory Neurons): Neurons that carry sensory information from the body to the central nervous system.

Efferent Neurons (Motor Neurons): Neurons that transmit motor commands from the central nervous system to muscles and glands.

Central Nervous System (CNS): The brain and spinal cord, responsible for processing and sending information throughout the body.

Spinal Cord: The long, thin, tubular structure extending from the brainstem that transmits neural signals between the brain and the rest of the body.

Peripheral Nervous System (PNS): The network of nerves outside the central nervous system that connects the CNS to limbs and organs.

Somatic Nervous System: The part of the peripheral nervous system that controls voluntary movements and sensory information.

Autonomic Nervous System: The part of the peripheral nervous system that regulates involuntary bodily functions like heartbeat and digestion.

Sympathetic Nervous System: The division of the autonomic nervous system responsible for the "fight or flight" response.

Parasympathetic Nervous System: The division of the autonomic nervous system responsible for "rest and digest" functions.

Psychoactive Drugs: Substances that alter mood, perception, or consciousness by affecting the nervous system.

Agonists: Drugs or substances that enhance the activity of neurotransmitters.

Antagonists: Drugs or substances that block or inhibit the activity of neurotransmitters.

Tolerance: The reduced effectiveness of a drug due to repeated use, requiring larger doses to achieve the same effect.

Dependence and Withdrawal: The physical and psychological symptoms that occur when a person stops using a drug on which they are dependent.

Stimulants: Drugs that increase activity in the central nervous system, leading to heightened alertness and energy.

Depressants: Drugs that decrease activity in the central nervous system, resulting in relaxation and drowsiness.

Hallucinogens (Psychedelics): Drugs that alter perception, mood, and cognitive processes, often causing hallucinations.

Opiates: Drugs derived from the opium poppy that relieve pain and induce euphoria, such as morphine and heroin.

Hindbrain: The part of the brain including the medulla, pons, and cerebellum, responsible for basic life functions and motor control.

Medulla: The brainstem structure that controls vital functions like heartbeat and breathing.

Pons: The brainstem structure involved in regulating sleep, respiration, and facial movements.

Cerebellum: The brain structure responsible for coordination, balance, and fine motor control.

Midbrain: The central part of the brain involved in vision, hearing, and motor control.

Reticular Formation (Reticular Activating System): A network of neurons in the brainstem that regulates alertness and attention.

Forebrain: The largest part of the brain, including structures such as the thalamus, hypothalamus, amygdala, and hippocampus, involved in higher-order functions.

Thalamus: The brain structure that relays sensory information to the appropriate areas of the cortex.

Hypothalamus: The brain region that controls homeostasis, including temperature regulation, hunger, and the endocrine system.

Amygdala: The brain structure involved in emotion regulation and memory processing, particularly fear.

Hippocampus: The brain structure crucial for the formation of new memories and spatial navigation.

Limbic System: A group of structures in the forebrain involved in emotion, motivation, and memory.

Cerebral Cortex: The outer layer of the brain responsible for complex cognitive functions, including perception and decision-making.

Hemispheres: The two halves of the brain, each with specialized functions.

Left Hemisphere: The brain hemisphere typically associated with language, logic, and analytical tasks.

Right Hemisphere: The brain hemisphere generally linked to creativity, spatial ability, and holistic thinking.

Brain Lateralization: The concept that certain mental processes and functions are more dominant in one hemisphere of the brain than the other.

Corpus Callosum: The thick band of nerve fibers connecting the left and right hemispheres of the brain, allowing for communication between them.

Lobes: The major divisions of the cerebral cortex, each responsible for different functions.

Association Area: Regions of the cerebral cortex involved in integrating sensory and motor information and higher cognitive functions.

Frontal Lobes: Brain regions involved in executive functions, planning, problem-solving, and motor control.

Broca’s Area: The area in the frontal lobe associated with speech production.

Wernicke’s Area: The area in the temporal lobe associated with language comprehension.

Motor Cortex: The region in the frontal lobe responsible for voluntary muscle movements.

Parietal Lobes: Brain regions involved in processing sensory information such as touch and spatial awareness.

Sensory Cortex: The area in the parietal lobe responsible for processing sensory input from the body.

Occipital Lobes: Brain regions at the back of the brain responsible for visual processing.

Temporal Lobes: Brain regions located on the sides of the brain involved in hearing, language, and memory

Brain Plasticity : The brain's ability to reorganize itself by forming new neural connections throughout life.

Accidents: Unplanned events that result in injury or damage, often leading to neurological changes.

Lesions: Damaged or abnormal areas of tissue in the brain, typically caused by injury, disease, or surgery.

Electroencephalogram (EEG): A test that records electrical activity in the brain using electrodes placed on the scalp.

Computerized Axial Tomography (CAT or CT Scan): An imaging technique that uses X-rays to create detailed cross-sectional images of the body.

Magnetic Resonance Imaging (MRI Scan): A technique that uses strong magnetic fields and radio waves to produce detailed images of internal structures.

Positron Emission Tomography (PET Scan): An imaging test that uses radioactive tracers to observe metabolic processes and blood flow in the body.

Functional MRI (fMRI): An imaging technique that measures brain activity by detecting changes in blood flow.

Endocrine System: A collection of glands that produce hormones regulating metabolism, growth, and mood.

Consciousness: The state of being aware of and able to think about one's own existence, thoughts, and surroundings.

Levels of Consciousness: Different states of awareness ranging from full alertness to deep sleep or unconsciousness.

Sleep: A natural state of rest characterized by altered consciousness and reduced physical activity.

Sleep Cycles: Repetitive patterns of sleep stages that occur throughout the night, typically lasting about 90 minutes.

Sleep Stagesm: Different phases of sleep, including REM and non-REM stages, each with distinct brain activity patterns.

REM Sleep: A stage of sleep characterized by rapid eye movement, vivid dreams, and increased brain activity.

Sleep Disorders: Conditions that disrupt normal sleep patterns, including insomnia, narcolepsy, and sleep apnea.

Insomnia: A disorder marked by difficulty falling asleep or staying asleep.

Narcolepsy: A condition characterized by excessive daytime sleepiness and sudden, uncontrollable sleep attacks.

Sleep Apnea: A disorder where breathing repeatedly stops and starts during sleep.

Dreams: Mental experiences that occur during sleep, often involving vivid images, thoughts, and emotions.

Freudian Dream Interpretation: A theory suggesting dreams represent unconscious desires and conflicts.

Activation-Synthesis Dream Theory: A theory proposing dreams are the brain's attempt to make sense of random neural activity.

Information-Processing Dream Theory : The idea that dreams help process and organize information from the day.

Transduction: The process of converting sensory stimuli into neural signals that the brain can interpret.

Sensory Adaptation: The diminished sensitivity to a constant stimulus over time.

Sensory Habituation (Perceptual Adaptation): The decreased perception of a constant stimulus due to repeated exposure.

Sensation: The process of receiving and processing sensory information from the environment.

Energy Senses: Sensory systems that detect physical energy, such as light and sound.

Chemical Senses: Sensory systems that detect chemicals, including taste and smell.

Vision: The sense that allows the detection of light and the perception of images.

Cornea: The transparent, protective layer covering the front of the eye.

Pupil: The opening in the center of the iris that controls the amount of light entering the eye.

Lens: A transparent structure behind the iris that focuses light onto the retina.

Retina: The light-sensitive layer at the back of the eye that converts light into neural signals.

Optic Nerve: The nerve that transmits visual information from the retina to the brain.

Occipital Lobe: The brain region responsible for processing visual information.

Feature Detectors: Neurons in the visual cortex that respond to specific features of visual stimuli, such as edges and movement.

Visible Light: The portion of the electromagnetic spectrum that is visible to the human eye.

Rods and Cones: Photoreceptor cells in the retina: rods detect low light levels and cones detect color.

Bipolar Cells and Ganglion Cells: Types of neurons in the retina that transmit visual information from rods and cones to the optic nerve.

Fovea: The central part of the retina with the highest concentration of cones, responsible for sharp central vision.

Blind Spot: The area on the retina where the optic nerve exits, lacking photoreceptors and not able to detect light.

Trichromatic Theory: The theory that color vision is based on three types of color receptors: red, green, and blue cones.

Color Blindness: A condition where individuals have difficulty distinguishing certain colors due to defective cones.

Opponent-Process Theory: The theory that color perception is controlled by the activity of two opponent systems: red-green and blue-yellow.

Hearing: The sense that allows detection of sound waves and the perception of auditory information.

Sound Waves: Vibrations that travel through the air and are perceived as sound.

Cochlea: The spiral-shaped, fluid-filled structure in the inner ear that converts sound vibrations into neural signals.

Pitch Theories: Theories explaining how we perceive the frequency of sound, including place theory and frequency theory.

Nerve Deafness: Hearing loss due to damage to the auditory nerve or inner ear structures.

Touch: The sense that detects pressure, temperature, and pain through receptors in the skin.

Gate-Control Theory: A theory suggesting that pain perception is regulated by a "gate" mechanism in the spinal cord that can be opened or closed.

Taste (Gustation): The sense responsible for detecting flavors through taste buds on the tongue.

Smell (Olfaction): The sense responsible for detecting odors through receptors in the nasal cavity.

Vestibular Sense: The sense of balance and spatial orientation, controlled by the inner ear.

Kinesthetic Sense: The sense that provides feedback on body position and movement through receptors in muscles and joints.

Absolute Threshold: The minimum intensity of a stimulus that can be detected 50% of the time.

Subliminal Messages: Stimuli that are below the threshold of conscious awareness but may still influence behavior.

Difference Threshold: The minimum difference between two stimuli required to notice a change 50% of the time.

Weber’s Law: A principle stating that the just noticeable difference between two stimuli is proportional to the magnitude of the original stimulus.