Modules 3 & 4: Genetics, Nervous System, Consciousness, Sleep, and Substance Use

Vocabulary flashcards covering key definitions, principles, anatomical structures, sleep stages, sleep disorders, and substance use disorders from Modules 3 and 4.

Law of Segregation

The genetic principle stating that each organism carries two alleles for every trait, and these alleles separate during gamete formation.

Law of Independent Assortment

The principle stating that genes for different traits are passed independently of one another, creating genetic variation.

Genotype

The genetic makeup of an organism or alleles passed down from the parents.

Phenotype

The observable traits expressed by an organism, influenced by both genotype and environment.

Allele

The physical expression of genes.

Punnett Square

A tool that predicts possible genetic outcomes based on the genetic makeup of the parents.

Homozygous

Having identical alleles for a given trait.

Heterozygous

Having two different alleles for a given trait.

Nerves

Pathways that conduct electrical signals from one part of the body to another.

Central Nervous System (CNS)

Consists of the brain and spinal cord; sends signals back to the PNS.

Peripheral Nervous System (PNS)

The division of the nervous system that sends signals from the brain to the rest of the body.

Somatic System

The part of the nervous system responsible for sensory functions and voluntary movement.

Neuron

The smallest unit of the nervous system; neurons bundle together to form nerves.

Afferent Neurons

Neurons that carry signals toward the brain and spinal cord.

Efferent Neurons

Neurons that carry signals out of the nervous system to the rest of the body.

Electrical Synapse

A type of synapse that is quicker and uncontrolled compared to a chemical synapse.

Chemical Synapse

A type of synapse that takes more time and is controlled.

Frontal Lobe

Brain region responsible for decision making, planning, judgement, voluntary movement, speech production, and personality.

Parietal Lobe

Brain region responsible for sensory integration (temperature, pain), spatial awareness, and body position.

Occipital Lobe

Brain region responsible for visual processing.

Temporal Lobe

Brain region responsible for auditory processing, language comprehension, and memory storage.

Cerebellum

Brain structure responsible for balance, coordination, and fine motor control.

Brainstem

Brain structure responsible for regulating breathing, heart rate, and sleep cycles.

Thalamus

Brain structure that acts as a sensory relay, directing incoming information to appropriate brain areas.

Hypothalamus

Brain structure that regulates hunger, thirst, temperature, circadian rhythm, and the endocrine system.

Amygdala

Brain structure responsible for emotion processing.

Hippocampus

Brain structure involved in the formation of new memories, learning, and spatial navigation.

Motor Cortex

Cerebral area that initiates voluntary movements.

Somatosensory Cortex

Cerebral area that processes touch, pressure, pain, and sensations.

Consciousness

Awareness of internal stimuli (including pain, hunger, thirst, sleepiness, thoughts, and emotions) as well as awareness of ourselves and our environment.

Higher-Level Awareness

A level of awareness that is focused, goal-directed, and controlled (e.g., studying).

Lower-Level Awareness

A level of awareness that is automatic, habitual, and requires minimal attention (e.g., daydreaming).

Altered State of Consciousness

A state marked by distorted or shifted perception and awareness, often induced by drugs or sleep deprivation.

Subconscious

A level of mental activity that is below active awareness, but still functionally active (e.g., during sleep).

Cognitive Neuroscience

The study of how brain activity is linked with mental processes.

Selective Attention

The focusing of conscious awareness on a particular stimulus or group of stimuli.

Sleep

A state marked by relatively low levels of physical activity and reduced sensory awareness that is distinct from periods of rest that occur during wakefulness.

Wakefulness

A state characterized by high levels of sensory awareness, thought, and behavior.

Biological Rhythm

Internal rhythms of biological activity.

Circadian Rhythm

A biological rhythm that takes place over a period of about $24\text{ hours}$.

Suprachiasmatic Nucleus (SCN)

The brain's clock mechanism located in an area of the hypothalamus.

Pineal Gland

An endocrine structure located inside the brain that releases melatonin; involved in regulating various biological rhythms and the immune system during sleep.

Sleep Regulation

The brain's control of switching between sleep and wakefulness as well as coordinating this cycle with the outside world.

Jet Lag

A collection of symptoms resulting from a mismatch between internal circadian cycles and the environment, including fatigue, sluggishness, irritability, and insomnia.

Sleep Debt

A state that occurs when a person does not get sufficient sleep on a chronic basis.

Pons

A brain structure that is important for regulating rapid eye movement (REM) sleep.

Beta Waves

Brain waves that dominate brain activity during the day.

Rapid Eye Movement (REM) Sleep

A sleep stage characterized by darting movements of the eyes under closed eyelids, dreaming, and paralysis of muscle systems (except those associated with respiration and heart activity).

NREM Stage One

The transition stage from wakefulness to sleep marked by an overall decrease in muscle tension and body temperature, initially producing alpha waves and later theta waves.

Alpha Waves

Brain waves produced in early NREM Stage One that are lower in frequency and variation.

Theta Waves

Brain waves produced later in NREM Stage One and during Stage Two, exhibiting lower frequencies and amplitudes.

NREM Stage Two

A period of deep relaxation characterized by theta waves, sleep spindles, and K-complexes.

Sleep Spindle

A rapid burst of higher frequency brain waves occurring in Stage Two sleep that may be important for learning and memory (memory support and motor skill learning).

K-Complex

A very high amplitude pattern of brain activity occurring in Stage Two sleep that may arise in response to environmental stimuli.

NREM Stage Three

Deep, slow-wave sleep characterized by delta waves, where heart rate and respiration rate are at their lowest; supports physical restoration, growth hormone release, and declarative memories.

Delta Waves

Brain waves low in frequency and high in amplitude that characterize Stage Three sleep.

REM Rebound

The phenomenon where a person deprived of sleep quickly re-enters REM sleep when sleeping again in an effort to make up for lost REM time.

Manifest Content

The actual storyline or literal content of a dream.

Latent Content

The hidden psychological meaning of a dream.

Collective Unconscious

A concept described by Carl Jung as a theoretical repository of information believed to be shared by all human beings.

Lucid Dream

A dream state in which certain aspects of wakefulness are maintained, allowing the dreamer to become aware that they are dreaming and potentially control the dream content.

Insomnia

A sleep disorder affecting $10\text{--}30\%$ of adults characterized by consistent difficulty falling or staying asleep, leading to increased fatigue, irritability, and decreased concentration.

Parasomnia

A group of sleep disorders affecting $1\text{--}5\%$ of adults involving unwanted, disruptive motor activity or experiences during sleep, occurring in either REM or NREM phases.

Sleepwalking (Somnambulism)

A parasomnia in which the sleeper engages in relatively complex behaviors like walking or driving while asleep; most commonly occurs during slow-wave sleep.

REM Sleep Behavior Disorder (RBD)

A sleep disorder occurring when normal REM muscle paralysis does not take place, resulting in high levels of physical activity (e.g., kicking, slapping, yelling) during disturbing dreams.

Restless Leg Syndrome

A condition affecting $5\text{--}10\%$ of adults causing uncomfortable sensations in the legs during inactivity or when attempting to fall asleep.

Night Terrors

Episodes that result in a sense of panic in the sufferer, often accompanied by screaming and attempts to escape the immediate environment.

Obstructive Sleep Apnea

A type of sleep apnea occurring when an individual's airway becomes physically blocked during sleep.

Central Sleep Apnea

A form of sleep apnea caused by disruptions in the signals sent from the brain that regulate breathing.

Continuous Positive Airway Pressure (CPAP)

A treatment device for sleep apnea with a mask fitted over the nose and mouth connected to a pump that forces air into airways to keep them open.

Sudden Infant Death Syndrome (SIDS)

A condition in which an infant suddenly stops breathing during sleep and dies.

Narcolepsy

A sleep disorder affecting $<0.05\%$ of adults characterized by an irresistible urge to fall asleep at inopportune times.

Physical Dependence

Changes in normal bodily functions such that the user will experience physiological withdrawal symptoms upon cessation of drug use.

Psychological Dependence

An emotional, rather than physical, need for a drug, often used to relieve psychological distress.

Stimulants

Drugs that tend to increase overall levels of neural activity; can produce euphoric highs and intense feelings of elation and pleasure.

Agonist

A substance that stimulates or increases neurotransmitter activity (e.g., opioids or benzodiazepines).

Antagonist

A substance that blocks or inhibits neurotransmitter activity (e.g., naloxone, antipsychotics).

Tolerance

The physiological state where an individual requires increasingly larger doses of a drug to achieve the original effect.

Withdrawal

A variety of negative physiological and psychological symptoms experienced when use of an addictive substance is discontinued.

Hypnosis

A calm, trance-like state of extreme self-focus and attention where minimal attention is paid to external stimuli, characterized by high suggestibility and increased theta waves.

Meditation

The practice of focusing attention on a single target to cultivate awareness, focus, emotional balance, and calm, associated with increases in alpha and theta waves.

Dissociation

A dual processing state characterized by a split in consciousness.

Disinhibitors

Substances that impair the brain's judgement centers while reducing self-awareness and self-control.

Hallucinogens

A class of drugs (also known as psychedelics) that distort sensory perceptions.