Flashcards Psychology: Neurons, Neurotransmitters & Brain Structures

Neurons

Specialized cells in the nervous system that process and transmit information via electrical and chemical signals.

Cell Body (Soma)

The central part of a neuron that coordinates information-processing tasks and keeps the cell alive.

Dendrites

Branch-like structures that receive information from other neurons and convey it toward the cell body.

Axon

A long, single extension that transmits electrical impulses away from the cell body toward other neurons, muscles, or glands.

Myelin Sheath

An insulating layer of fatty material wrapped around axons, accelerating signal transmission.

Glial Cells

Support cells in the nervous system that nourish, protect, and physically support neurons.

Synapse

The microscopic junction or gap between the axon terminal of one neuron and the dendrite/cell body of another.

Resting Potential

The electrical charge difference (approx.

−70 mV) across a neuron's membrane when it is inactive.

Action Potential

An all-or-none electrical signal conducted along the length of a neuron's axon to the synapse.

Refractory Period

The brief recovery window following an action potential during which a new impulse cannot be initiated.

Terminal Buttons

Knob-like structures at the end of an axon that release neurotransmitters into the synapse.

Neurotransmitters

Chemicals that cross the synaptic gap to bind with receptors on receiving neurons, relaying signals.

Receptors

Specialized proteins on postsynaptic membranes that receive specific neurotransmitters.

Sensory Neurons

Carry incoming sensory information from external receptors to the brain via the spinal cord.

Motor Neurons

Carry outgoing instructions from the central nervous system to muscles and glands.

Interneurons

Neurons that connect sensory neurons, motor neurons, or other interneurons within the central nervous system.

Acetylcholine (ACh)

Neurotransmitter involved in voluntary motor control, memory, and learning.

Dopamine

Neurotransmitter regulating motor behavior, motivation, pleasure, and emotional arousal.

Glutamate

Major excitatory neurotransmitter involved in memory formation and neural plasticity.

GABA (Gamma-Aminobutyric Acid)

Major inhibitory neurotransmitter that dampens neural activity.

Norepinephrine

Neurotransmitter influencing mood, vigilance, and heightened awareness.

Serotonin

Neurotransmitter regulating sleep, wakefulness, eating, and mood stability.

Endorphins

Endogenous neuropeptides acting as natural painkillers and mood enhancers.

Agonists

Drugs that bind to receptors and mimic or enhance a neurotransmitter's action.

Antagonists

Drugs that block or inhibit the action of specific neurotransmitters.

Central Nervous System (CNS)

Composed of the brain and spinal cord; processes information and controls bodily functions.

Peripheral Nervous System (PNS)

All nerve tissue outside the CNS; connects the CNS to limbs and organs.

Somatic Nervous System

Subdivision of PNS that controls voluntary skeletal muscle movements and conveys sensory info.

Autonomic Nervous System (ANS)

Subdivision of PNS controlling involuntary bodily functions (heartbeat, digestion).

Sympathetic Nervous System

Division of ANS responsible for mobilizing body resources during threats ("fight-or-flight").

Parasympathetic Nervous System

Division of ANS that calms the body and conserves energy ("rest-and-digest").

Spinal Reflexes / Reflex Arc

Automatic, involuntary responses to sensory stimuli executed directly by the spinal cord.

Hindbrain

Structural region coordinating vital bodily functions; includes medulla, pons, and cerebellum.

Medulla

Hindbrain structure controlling vital involuntary functions like heart rate, breathing, and circulation.

Reticular Formation

Brainstem region regulating sleep, wakefulness, and arousal.

Cerebellum

Hindbrain structure controlling fine motor coordination, balance, and procedural motor skills.

Pons

Hindbrain structure serving as a relay station connecting the cerebellum to the rest of the brain.

Tectum & Tegmentum

Midbrain structures involved in orienting toward sensory stimuli and movement/arousal.

Cerebral Cortex

Outermost layer of the brain, divided into two hemispheres, responsible for complex cognitive functions.

Subcortical Structures

Deep brain areas (e.g., thalamus, limbic system) controlling emotion, memory, and basic drives.

Thalamus

Main sensory relay station that filters and directs sensory input (except smell) to the cortex.

Hypothalamus

Regulates bodily homeostasis, temperature, hunger, thirst, and autonomic functions.

Hippocampus

Limbic structure critical for creating new long-term explicit memories.

Amygdala

Limbic structure playing a central role in processing emotional memories and fear responses.

Basal Ganglia

Subcortical structures directing intentional movements and motor control.

Endocrine System

Glandular network producing hormones that travel through the bloodstream to alter body functions.

Pituitary Glands

"Master gland" releasing hormones that direct actions of other endocrine glands.

Corpus Callosum

Thick band of nerve fibers connecting the left and right cerebral hemispheres.

Lobes (Occipital, Parietal, Temporal, Frontal)

Cortex regions processing vision (occipital), touch/spatial processing (parietal), hearing/language (temporal), and decision-making/motor planning (frontal).

Association Areas

Cortical zones that integrate diverse sensory input into coherent, complex understandings.

Mirror Neurons

Neurons activated both when performing an action and when observing someone else perform it.

Gene / Chromosomes

Basic units of hereditary information composed of DNA, organized into chromosome pairs.

Epigenetics / Marks

Environmental influences modifying gene expression without altering underlying DNA sequences.

DNA Methylation & Histone Modification

Epigenetic mechanisms silencing gene expression (methylation) or modifying DNA accessibility (histone changes).

Heritability

Measure indicating the proportion of population variation in a trait attributable to genetic differences.

Electroencephalograph (EEG)

Device recording electrical brain activity via scalp electrodes.

Sensation

The stimulation of sensory receptors by raw environmental energy.

Perception

The brain's organization, identification, and interpretation of sensory signals into meaningful mental representations.

Transduction

Process converting physical environmental stimuli into neural impulses for the CNS.

Sensory Adaptation

Decreased sensory responsiveness following prolonged exposure to an unchanging stimulus.

Psychophysics

Branch of psychology studying relationships between physical stimulus properties and psychological sensations.

Absolute Threshold

Minimum intensity of a stimulus needed for detection 50% of the time.

Sensitivity & Acuity

Ability to detect subtle stimuli (sensitivity) and sharpness/clarity of discrimination (acuity).

Just Noticeable Difference (JND)

Minimal change in a stimulus needed to detect a difference 50% of the time.

Weber's Law

Principle stating the JND is a constant proportion of the initial stimulus magnitude.

Signal Detection Theory

Framework analyzing decision processes under uncertainty, distinguishing sensory sensitivity from decision criteria.

Retina

Light-sensitive tissue lining the back of the eye containing photoreceptor cells.

Accommodation

Process by which the eye's lens changes shape to focus light on the retina.

Cones & Rods

Photoreceptors for detailed color vision in bright light (cones) vs. low-light black-and-white vision (rods).

Fovea

Central region of the retina containing high cone density for maximum visual acuity.

Blind Spot

Location on the retina lacking photoreceptors where the optic nerve exits the eye.

Area V1

Primary visual cortex in the occipital lobe processing basic orientation and edge features.

Color-Opponent System

Theory proposing pairs of visual mechanisms (red-green, blue-yellow, black-white) working in opposition.

Visual Receptive Field

Specific regional space where a stimulus triggers a given visual neuron to fire.

Binding Problem & Feature-Integration Theory

Question of how features are unified, answered by proposing attention binds separate features together.

Parallel Processing

Brain's capability to process multiple features (color, motion, shape) simultaneously.

Illusory Conjunction

Perceptual error combining features from different objects incorrectly due to lack of focused attention.

Attention

Selective focusing of conscious awareness on specific stimuli or aspects of an environment.

Perceptual Constancy / Contrast

Perceiving objects as unchanged despite altering retinal images (constancy), or accentuating differences between adjacent stimuli (contrast).

Perceptual Organization

Gestalt principles governing how visual elements are grouped into unified shapes or patterns.

Monocular & Binocular Cues

Depth cues requiring one eye (monocular, e.g., linear perspective) or both eyes (binocular disparity).

Apparent Motion

Perception of movement created by rapidly alternating stationary images.

Spatial & Temporal Acuity

Spatial sharpness (visual detail) vs. temporal precision (detecting changes over time).

Multisensory & Ventriloquist Illusion

Integration of multiple senses; illusion where sounds are misattributed to a visible source.

Change & Inattentional Blindness

Failing to notice environmental changes (change) or visible objects (inattentional) due to diverted attention.

Pitch

Auditory dimension corresponding to wave frequency

Loudness Auditory dimension corresponding to amplitude

Timbre

Auditory dimension corresponding to complexity/quality.

Cochlea

Fluid-filled spiral structure in the inner ear containing auditory receptor cells.

Basilar Membrane

Membrane inside the cochlea that vibrates in traveling waves when stimulated by sound.

Inner Hair Cells

Sensorimotor auditory receptor cells transducing fluid motion into neural impulses.

Area A1

Primary auditory cortex located in the temporal lobe.

Place Code & Temporal Code

Pitch mechanisms encoding high frequencies via location on basilar membrane (place) vs. low frequencies via firing rates (temporal).

Haptic Perception

Active exploration of environment through combined touch and kinesthetic feedback.

Referred Pain

Pain felt in a body location distinct from the internal organ causing the painful stimulus.

Gate-Control Theory

Theory proposing neural gates in the spinal cord can open or close to block or transmit pain signals.

Proprioception & Vestibular System

Sense of body position/limb movement (proprioception) and balance/head spatial orientation (vestibular).

Olfactory Receptor Neurons (ORNs) & Bulb

Receptor cells detecting odorants (ORNs) sending signals to the brain's olfactory bulb.

Pheromones

Biochemical odorants released by organisms affecting behavior or physiology of same-species members.