Neuroscience AP Psych (real one)

Neuron

A specialized nerve cell that receives, processes, and transmits information through electrical impulses and chemical signals.

Glial Cells

Cells that support, nourish, protect, and insulate neurons and help maintain a healthy nervous system.

Dendrite

Branchlike extensions of a neuron that receive signals from other neurons and carry them toward the cell body.

Cell Body

The part of a neuron containing the nucleus that maintains the cell and integrates incoming signals.

Axon

The long extension of a neuron that carries electrical impulses away from the cell body toward other cells.

Terminal buttons

Tiny structures at the ends of axons that release neurotransmitters into the synapse to communicate with other cells.

Myelin Sheath

A fatty insulating layer surrounding some axons that speeds up the transmission of neural impulses.

Excitatory cell

A neuron that increases the likelihood that a receiving neuron will fire an action potential by producing excitatory signals.

Inhibitory cell

A neuron that decreases the likelihood that a receiving neuron will fire an action potential by producing inhibitory signals.

Resting Potential

The electrical charge difference across a neuron's membrane when it is not firing, usually about -70 millivolts.

Threshold

The level of stimulation a neuron must reach to trigger an action potential, typically around -55 millivolts.

Cell membrane

The selectively permeable outer boundary of a neuron that regulates which substances enter and leave the cell.

Action Potential

A brief electrical impulse that travels down an axon when a neuron reaches its threshold.

Sodium ions

Positively charged ions that enter a neuron during depolarization, making the inside less negative.

Potassium ions

Positively charged ions that move out of a neuron during repolarization, helping restore its negative internal charge.

Depolarization

The phase when sodium ions enter a neuron, making its internal charge less negative and potentially triggering an action potential.

Hyperpolarization

A temporary phase when a neuron's internal charge becomes more negative than its resting potential, making firing less likely.

Repolarization

The phase when a neuron returns toward its negative resting charge after an action potential, largely as potassium ions exit.

All-Or-None Response

The principle that a neuron fires a full action potential once threshold is reached or does not fire one at all.

Refractory Period

The brief period after an action potential when a neuron cannot fire another action potential or requires stronger stimulation.

Synapse

The junction between neurons, where chemical or electrical signals allow communication between cells.

Neurotransmitters

Chemical messengers released by neurons that cross synapses and influence other neurons, muscles, or glands.

Reuptake

The process by which a sending neuron reabsorbs neurotransmitters from the synapse after their release.

Acetylcholine (ACh)

A neurotransmitter involved in muscle movement, learning, memory, and attention; reduced ACh activity is associated with Alzheimer's disease.

Dopamine

A neurotransmitter involved in movement, motivation, reward, attention, and learning; imbalances are associated with disorders such as Parkinson's disease and schizophrenia.

Serotonin

A neurotransmitter that helps regulate mood, sleep, appetite, and arousal; it is a target of many antidepressant medications.

Norepinephrine

A neurotransmitter and hormone involved in alertness, attention, arousal, and the body's stress response.

Epinephrine

A hormone and neurotransmitter, also called adrenaline, that increases arousal and prepares the body for fight-or-flight responses.

GABA

The brain's primary inhibitory neurotransmitter, which reduces neural activity and helps regulate anxiety, relaxation, and sleep.

Glutamate

The brain's primary excitatory neurotransmitter, important for learning, memory, and synaptic plasticity.

Endorphins

Naturally produced chemicals that reduce pain and can create feelings of pleasure or well-being.

Substance P

A neuropeptide that transmits pain signals and contributes to inflammation and pain perception.

Myasthenia Gravis

An autoimmune disorder that disrupts communication between nerves and muscles, causing muscle weakness, often by affecting acetylcholine receptors.

Lock and Key Mechanism

The principle that a neurotransmitter binds to specific receptors whose shapes and properties allow particular chemical signals to activate or inhibit a cell.

Agonist

A substance that increases a neurotransmitter's effects by mimicking it or enhancing its activity at receptors.

Antagonist

A substance that blocks or reduces a neurotransmitter's effects, often by occupying its receptors without activating them.

The Nervous System

The body's network of neurons and supporting cells that receives information, processes it, and coordinates responses.

Central Nervous System

The brain and spinal cord; it processes information and coordinates thoughts, sensations, movements, and other responses.

Interneurons

Neurons located mainly in the central nervous system that connect other neurons and help process information.

The Peripheral Nervous System

All nerves outside the brain and spinal cord; it connects the central nervous system with the rest of the body.

Somatic Nervous System

The division of the peripheral nervous system responsible for sensory information and voluntary control of skeletal muscles.

Autonomic Nervous System

The division of the peripheral nervous system that regulates involuntary functions such as heart rate, digestion, and breathing.

Sympathetic Nervous System

The autonomic division that mobilizes energy during stress or danger; it produces the fight-or-flight response.

Parasympathetic Nervous System

The autonomic division that conserves energy and supports rest, digestion, and recovery; it produces the rest-and-digest response.

Sensory Neurons

Neurons that carry information from sensory receptors toward the brain and spinal cord.

Motor Neurons

Neurons that carry commands from the brain and spinal cord to muscles and glands.

Endocrine System

A network of glands that releases hormones into the bloodstream to regulate growth, metabolism, reproduction, stress, and other functions.

Hormones

Chemical messengers released by endocrine glands into the bloodstream that influence target cells and body processes.

Adrenaline

A hormone, also called epinephrine, released by the adrenal glands that increases heart rate, alertness, and energy availability during stress.

Melatonin

A hormone produced mainly by the pineal gland that helps regulate circadian rhythms and signals that it is time for sleep.

Pituitary Gland

An endocrine gland controlled by the hypothalamus that releases hormones regulating growth and influencing other endocrine glands.

Thyroid Gland

A gland in the neck that produces hormones regulating metabolism, energy use, growth, and development.

Parathyroid Gland

Small glands behind the thyroid that regulate blood calcium levels through parathyroid hormone.

Adrenal Gland

Glands above the kidneys that release hormones, including adrenaline and cortisol, involved in stress responses and other body functions.

Gonads

The reproductive glands—ovaries and testes—that produce sex hormones and reproductive cells.

Lesion

Damage to a specific area of brain tissue, sometimes studied to understand the functions of that area.

EEG

An electroencephalogram; a test that records the brain's electrical activity through electrodes placed on the scalp.

Pet Scan

A positron emission tomography scan that uses a radioactive tracer to measure metabolic activity and other processes in the brain.

MRI

Magnetic resonance imaging; a technique that uses magnetic fields and radio waves to create detailed images of brain structures.

Brain Stem

The lower part of the brain connecting it to the spinal cord; it helps regulate essential functions such as breathing, heart rate, and arousal.

Hindbrain

The lower brain region containing structures such as the medulla, pons, and cerebellum that support vital functions, sleep, and coordination.

Midbrain

A brain region involved in movement, attention, alertness, and processing certain visual and auditory information.

Forebrain

The largest and most complex brain division, including structures involved in emotion, memory, sensory processing, and higher thinking.

Medulla

A brain-stem structure that controls vital automatic functions, including breathing, heart rate, and blood pressure.

Reticular Formation

A network of neurons in the brain stem involved in alertness, arousal, attention, and the sleep-wake cycle.

Thalamus

The brain's major sensory relay station, directing most sensory information to the appropriate areas of the cerebral cortex; smell is the major exception.

Cerebellum

A structure at the back of the brain that coordinates balance, posture, fine motor movements, and motor learning.

Plasticity

The brain's ability to change and reorganize its connections and functioning in response to experience, learning, or injury.

Pons

A brain-stem structure that helps regulate sleep, arousal, breathing, and communication between brain regions; it also contributes to REM sleep.

Limbic System

A group of interconnected brain structures involved in emotion, motivation, memory, and reward.

Amygdala

A structure involved in processing emotions, especially fear and threat, and in emotional learning.

Hippocampus

A structure essential for forming and consolidating new explicit memories and supporting spatial memory.

Hypothalamus

A brain region that maintains homeostasis by regulating hunger, thirst, body temperature, hormones, and other basic drives.

Cerebral Cortex

The outer layer of the cerebrum, responsible for higher-level processes such as perception, language, reasoning, planning, and voluntary movement.

Frontal Lobe

The brain lobe involved in planning, decision-making, personality, impulse control, problem-solving, and voluntary movement.

Parietal Lobe

The brain lobe that processes bodily sensations and contributes to spatial awareness and integrating sensory information.

Occipital Lobe

The brain lobe primarily responsible for processing visual information.

Temporal Lobe

The brain lobe involved in hearing, language comprehension, memory, and recognizing objects and faces.

Somatosensory Cortex

The strip of cortex in the parietal lobe that processes touch, pressure, pain, temperature, and body-position information.

Motor Cortex

The strip of cortex in the frontal lobe that controls voluntary skeletal muscle movements.

Broca’s Area

An area usually in the left frontal lobe that is important for producing speech; damage can cause slow, effortful speech.

Wernicke’s Area

An area usually in the left temporal region that is important for understanding language; damage can cause fluent but poorly understood speech and impaired comprehension.

Fusiform Gyrus

A region on the underside of the temporal and occipital lobes involved in recognizing complex visual patterns, especially faces and objects.

Aphasia

A language impairment caused by brain damage that can affect speaking, understanding, reading, or writing.

Left Hemisphere’s Specialties

In most people, the left hemisphere is dominant for language and is often more involved in sequential and analytical processing.

Right Hemisphere’s Specialties

The right hemisphere is often more involved in spatial processing, recognizing patterns and faces, and interpreting emotional tone.

Contralateral Hemisphere Organization

Each cerebral hemisphere primarily controls movement and receives sensory information from the opposite side of the body.

Corpus Callosum

A thick band of nerve fibers connecting the brain's two cerebral hemispheres and allowing them to share information.

Split Brain Patients

People whose corpus callosum has been surgically severed, usually to treat severe epilepsy, allowing researchers to study how the hemispheres process information separately.

Consciousness

Awareness of oneself and one's surroundings, including thoughts, sensations, and experiences.

Unconsciousness

A state in which a person lacks awareness of their surroundings; in psychoanalytic theory, unconscious processes are mental contents outside conscious awareness.

Subconsciousness

An informal term for mental processes occurring outside conscious awareness that can still influence thoughts and behavior.

Circadian Rhythm (Daily Cycle)

The body's roughly 24-hour biological cycle that regulates sleep-wake patterns, alertness, temperature, and hormone release.

GABA

The brain's primary inhibitory neurotransmitter; it decreases neural activity and helps regulate relaxation and sleep.

Suprachiasmatic nucleus

A small group of neurons in the hypothalamus that acts as the body's master circadian clock, using light information to help synchronize daily rhythms.

90 to 110 minute sleep cycle

A typical sleep cycle lasting about 90–110 minutes, progressing through NREM stages and REM sleep; the pattern repeats several times per night.

Sleep stages in order

A typical cycle progresses through NREM 1, NREM 2, NREM 3, and then REM sleep; deeper NREM sleep and REM periods vary across the night.

Beta Waves

Fast, low-amplitude brain waves associated with alertness, active thinking, and focused mental activity.

Alpha Waves

Brain waves associated with relaxed wakefulness, especially when a person is calm with their eyes closed.

Theta Waves

Brain waves associated with light sleep, drowsiness, and NREM 1; they may also occur during some waking states.