FULL Unit 1 flashcards

Vocabulary flashcards generated from AP Psychology Unit 1 notes covering Biological Bases of Behavior, neural communication, brain structures, sleep, and sensory mechanisms.

Heredity

The biological transfer of genetic characteristics and traits from parents to their biological offspring.

Heritability

A statistical estimate measuring the proportion of variation in a specific trait within a population that can be attributed to genetic differences.

Nurture

The total of environmental factors, including upbringing, education, social influences, and culture, that shape individual development.

Epigenetics

The study of how environmental factors (such as stress, diet, and lifestyle) alter gene expression without altering the underlying $DNA$ sequence.

Eugenics

The practice or advocacy of controlled selective breeding to alter a population's genetic traits, historically misused to justify discrimination.

Monozygotic Twins

Identical twins formed when $1$ single fertilized egg splits into $2$, resulting in individuals with nearly identical genetic profiles.

Dizygotic Twins

Fraternal twins formed when $2$ separate eggs are fertilized by $2$ separate sperm cells, sharing approximately $50\%$ of their genetic material.

Central Nervous System (CNS)

The core division of the human nervous system consisting of the brain and the spinal cord, responsible for processing information and directing responses.

Peripheral Nervous System (PNS)

The neural network connecting the Central Nervous System (CNS) to the limbs, sensory receptors, organs, and body tissue.

Somatic Nervous System (SNS)

The subsystem of the Peripheral Nervous System that controls voluntary skeletal muscle movements and carries sensory information to the CNS.

Autonomic Nervous System (ANS)

The self-regulating subsystem of the Peripheral Nervous System that manages involuntary body functions such as heart rate, digestion, and respiratory rate.

Sympathetic Nervous System

The branch of the Autonomic Nervous System that mobilizes energy and elevates physiological arousal for fight-or-flight responses.

Parasympathetic Nervous System

The branch of the Autonomic Nervous System that calms the body and conserves energy, returning physiological systems to a resting state.

Glial Cells

Supportive neural cells that protect, nourish, insulate, and maintain homeostasis for neurons in the nervous system.

Sensory Neurons (Afferent)

Neurons that carry incoming signals from body sensory receptors inward toward the central nervous system.

Motor Neurons (Efferent)

Neurons that carry outgoing motor commands away from the central nervous system to muscles and glands.

Interneurons

Neurons located exclusively within the central nervous system that internalize, process, and transmit messages between sensory and motor neurons.

Reflex Arc

An automatic, rapid neural response loop triggered by a stimulus that routes through sensory receptors, spinal interneurons, and motor neurons without initial conscious brain processing.

Dendrites

The branching root-like extensions of a neuron that receive chemical messages from adjacent cells and conduct impulses toward the cell body.

Myelin Sheath

A protective fatty tissue layer wrapping around the axon of a neuron that significantly accelerates signal transmission speed.

Action Potential

A brief electrical impulse that travels down the axon of a neuron when its membrane potential crosses the firing threshold (approximately $-55\,\text{mV}$).

All-or-None Principle

The physiological rule stating that a neuron fires completely at full strength or not at all once threshold stimulus is reached.

Depolarization

The electrical change occurring when positively charged sodium ions ($\text{Na}^+$) flood into a neuron, neutralizing its negative internal charge to generate an action potential.

Refractory Period

A temporary resting period immediately following neural firing during which the neuron cannot generate another action potential until its resting potential is restored.

Resting Potential

The negative electrical charge of an inactive neuron's membrane relative to its external environment, typically around $-70\,\text{mV}$.

Reuptake

The reabsorption process by which excess neurotransmitters in the synaptic gap are taken back into the sending neuron's terminal buttons.

Glutamate

The brain's primary excitatory neurotransmitter; crucial for long-term potentiation, memory formation, and learning.

GABA (Gamma-Aminobutyric Acid)

The brain's primary inhibitory neurotransmitter; functions to slow neural excitability and reduce anxiety.

Acetylcholine (ACh)

A key neurotransmitter controlling muscle movement, attention, and memory storage; deficits are strongly associated with Alzheimer's disease.

Dopamine

A neurotransmitter regulating pleasure, reward anticipation, and voluntary movement; overactivity is linked to schizophrenia, while degradation leads to Parkinson's disease.

Substance P

A peptide neurotransmitter responsible for transmitting pain signals from peripheral nerves to the central nervous system.

Agonists

Chemical substances or drugs that enhance neural transmission by mimicking neurotransmitters or blocking their reuptake.

Antagonists

Chemical substances or drugs that inhibit neural transmission by blocking neurotransmitter receptor sites without activating them.

Medulla

The structure at the base of the brainstem that controls vital autonomic functions such as breathing, blood pressure, and heart rate.

Pons

A brainstem structure situated above the medulla that coordinates cross-body movements, relays sensory signals, and aids in sleep regulation.

Cerebellum

The brain structure located at the back of the brainstem regulating muscle coordination, physical balance, fine motor skills, and procedural memory.

Thalamus

The sensory switchboard atop the brainstem that receives and routes incoming sensory information (except smell) to appropriate cortical lobes.

Hypothalamus

A limbic structure below the thalamus directing key drive behaviors (fighting, fleeing, feeding, and mating) and regulating the endocrine system via the pituitary gland.

Suprachiasmatic Nucleus

A specialized cell cluster within the hypothalamus that regulates the sleep-wake cycle and circadian rhythms in response to light exposure.

Amygdala

A pair of almond-shaped limbic system structures deeply involved in emotional responses, particularly aggression, fear, and emotional memory consolidation.

Hippocampus

A limbic system structure crucial for processing declarative memories, spatial navigation, and converting short-term memories into long-term storage.

Corpus Callosum

A massive fiber bundle of nerve axons connecting the left and right cerebral hemispheres, facilitating direct neural communication between them.

Broca's Area

A region in the left frontal lobe controlling motor actions necessary for expressive speech production.

Wernicke's Area

A region in the left temporal lobe responsible for language comprehension and meaningful auditory processing.

Neuroplasticity

The structural and functional ability of the brain to adapt, reorganizing neural pathways in response to learning, experience, or physical injury.

Transduction

The sensory process through which physical energy from the environment is converted into electrical neural impulses for brain interpretation.

Absolute Threshold

The minimum level of stimulus energy needed to detect a stimulus at least $50\%$ of the time.

Sensory Adaptation

A reduction in sensory responsiveness resulting from continuous exposure to an unchanging, constant stimulus.

Gate Control Theory

The theory proposing that the spinal cord contains a neurological gate that can block or pass pain signals onward to the brain.

Vestibular Sense

The sensory system monitoring overall balance, spatial orientation, and body motion using fluid-filled canals in the inner ear.

Kinesthetic Sense

The sensory awareness monitoring the location, movement, and orientation of individual body parts through receptors in joints, tendons, and muscles.

Serotonin

A key neurotransmitter that modulates mood, sleep, hunger, and emotional arousal; deficits are strongly linked to clinical depression.

Endorphins

Endogenous opioid neurotransmitters released in response to pain or severe exercise that function as natural painkillers and mood enhancers.

Melatonin

A hormone produced by the pineal gland that promotes sleepiness in response to darkness.

Leptin

A hunger-inhibiting hormone secreted by fat cells that signals satiety to the brain.

Ghrelin

A hunger-arousing hormone secreted by an empty stomach that signals appetite stimulation to the hypothalamus.

Oxytocin

A hormone and neurotransmitter involved in social bonding, empathy, trust creation, and maternal attachment.

Stimulants

A class of psychoactive drugs that speed up central nervous system activity, elevating heart rate, cognitive alertness, and energy.

Depressants

A class of psychoactive drugs that reduce central nervous system activity, slowing physiological functions and mental processing.

Tolerance

The state where diminished responsiveness to a drug requires progressively larger doses to experience its initial physical or psychological effect.

Withdrawal

The unpleasant physical and psychological distress experienced when stopping the use of an addictive substance.

Occipital Lobes

Cortical regions at the rear of the cerebral cortex containing the primary visual cortex, responsible for processing visual information.

Temporal Lobes

Cortical regions situated above the ears containing the auditory cortex, processing sound, language comprehension, and long-term memory.

Frontal Lobes

Cortical regions responsible for high-level executive functions, planning, abstract reasoning, voluntary motor control, and personality traits.

Parietal Lobes

Cortical regions positioned behind the frontal lobes containing the somatosensory cortex, processing body touch and spatial perception.

Hemispheric Lateralization

The specialized allocation of specific cognitive processes and behavioral functions to either the left or right cerebral hemisphere.

Neurogenesis

The biological process involving the growth and formation of new functional brain neurons.

Electroencephalogram (EEG)

A test recording electrical brain-wave activity across the scalp using placed electrodes.

Functional Magnetic Resonance Imaging (fMRI)

A neuroimaging technique measuring real-time cerebral blood flow changes to display structure and functional activity.

Circadian Rhythm

An internal biological clock regulating sleepiness and body functions on a natural $24\text{-hour}$ cycle.

NREM-3 Sleep

The deepest slow-wave sleep stage characterized by high-amplitude delta waves, crucial for physical healing and bodily restoration.

REM Sleep

A recurring sleep stage featuring rapid eye movements, heightened brain activity, vivid dreams, and temporary muscle paralysis.

Insomnia

A persistent sleep disorder characterized by ongoing difficulty falling asleep, remaining asleep, or achieving restful sleep.

Causes: stress, anxiety, depression, or medical conditions

Symptoms: daytime fatigue, irritability, and difficulty concentrating, affecting overall quality of life.

Treatments: lifestyle changes, therapy, medication.

Narcolepsy

A neurological sleep disorder causing sudden, uncontrollable daytime sleep attacks directly entering REM sleep.

Causes: genetic factors, brain abnormalities, and neurotransmitter deficiencies.

Treatments: lifestyle changes, medications such as stimulants or antidepressants, and behavioral therapies.

Sleep Apnea

A sleep disorder causing repeated cessation of breathing during sleep, leading to frequent momentary awakenings.

Causes: obstruction of the airway, central nervous system issues, obesity, anatomical abnormalities.

Types: obstructive, central, complex

Treatment: lifestyle changes, CPAP machines, surgery, oral appliances.

Weber's Law

The principle stating that the just noticeable difference between two stimuli is a constant minimum proportion rather than a fixed absolute difference.

Retina

The light-sensitive inner membrane of the eye containing rods and cones that convert light energy into neural impulses.

Rods

Photoreceptors in the peripheral retina detecting black, white, and gray shades, critical for peripheral and low-light vision.

Cones

Photoreceptors concentrated in the central retina detecting fine visual details and color under well-lit conditions.

Fovea

The central focal pit in the retina containing a dense concentration of cones for maximum visual acuity.

Blind Spot

The point on the retina where the optic nerve exits the eye, lacking photoreceptors entirely.

Trichromatic Theory

The theory asserting that color vision relies on three cone types specialized for red, green, and blue light wavelengths.

Opponent-Process Theory

The theory asserting that color vision relies on opposing neural channels (red-green, blue-yellow, black-white).

Olfaction

The chemical sense of smell, routed directly through the olfactory bulb without relaying through the thalamus.

Gustation

The chemical sense of taste, processed by taste receptors inside papillae on the tongue.

Place Theory

An auditory theory stating that pitch perception depends on the exact position stimulated along the cochlea's basilar membrane.

Frequency Theory

An auditory theory stating that pitch perception depends on the speed or rate at which nerve impulses travel up the auditory nerve.