Neurology unit psych

All 3 slideshows

Neuron 

A nerve cell that communicates using electrical and chemical signals.

Synapse

The gap between two neurons where neurotransmitters are released.

Dendrite

Branch-like extensions that receive signals from other neurons

Axon

Long fiber that transmits electrical impulses away from the soma

Myelin Sheath 

Fatty layer that insulates axons and speeds up neural transmission.

Glial Cells

Support cells that nourish, insulate, and protect neurons

Node of Ranvier

Gaps in the myelin sheath that allow for faster signal conduction.

Multiple Sclerosis (MS)

Disease where the immune system attacks myelin, disrupting communication.

Resting Potential

Neuron’s stable negative charge when inactive (-70 mV).

Action Potential

Rapid electrical impulse when a neuron fires (+35 mV).

Depolarization

Sodium ions rush into the neuron, reversing charge.

Repolarization

Restoration of negative internal charge after firing.

Refractory Period

Brief time after firing when a neuron cannot fire again.

All-or-Nothing Principle

A neuron fires completely or not at all; intensity depends on frequency of firing.

Presynaptic Neuron

The neuron sending neurotransmitters

Postsynaptic Neuron

The neuron receiving neurotransmitters.

Reuptake

Reabsorption of neurotransmitters back into the presynaptic neuron.

Excitatory Neurotransmitter

Increases likelihood of an action potential (e.g., glutamate).

Inhibitory Neurotransmitter

Decreases likelihood of an action potential (e.g., GABA).

Acetylcholine

Neurotransmitter involved in movement, attention, and memory.

Dopamine

Controls movement, mood, and reward sensations.

Serotonin

Regulates mood, appetite, and sleep.

Norepinephrine

Triggers alertness and stress responses.

Agonist

A drug that enhances or mimics neurotransmitter effects.

Antagonist

A drug that blocks or inhibits neurotransmitter activity.

Central Nervous System (CNS)

Consists of the brain and spinal cord; integrates and processes information.

Peripheral Nervous System (PNS)

Connects the CNS to the rest of the body via nerves

Sensory Neurons

Carry information from senses to the CNS.

Motor Neurons

Send commands from the CNS to muscles and glands.

Interneurons

Connect neurons within the CNS.

Autonomic Nervous System

Controls involuntary actions (heart rate, digestion).

Somatic Nervous System

Controls voluntary movements and reflexes.

Sympathetic Nervous System

Activates “fight or flight” response.

Parasympathetic Nervous System

Activates “rest and digest” functions.

Spinal Cord

Pathway that transmits signals between brain and body.

Cerebrum

Responsible for higher thinking, divided into two hemispheres.

Cerebellum

Controls coordination, balance, and fine motor movement.

Brain Stem

Connects brain to spinal cord; regulates essential body functions.

Midbrain

Processes auditory and visual reflexes.

Pons

Regulates breathing and communication between brain areas.

Medulla

Controls heart rate, breathing, and digestion.

Thalamus

Relays sensory and motor information to the cerebral cortex.

Hypothalamus

Maintains homeostasis, regulates hunger, sleep, and emotion.

Basal Ganglia

Coordinates movement and reward processing.

Amygdala

Controls emotions, fear, and survival instincts

Hippocampus

Important for learning and memory formation.

Cerebral Cortex

Outer wrinkled layer responsible for thought and personality.

Frontal Lobe

Controls planning, decision-making, and speech production.

Parietal Lobe

Processes touch and spatial awareness.

Temporal Lobe

Handles hearing, language, and memory.

Occipital Lobe

Responsible for visual processing.

Corpus Callosum

Connects left and right hemispheres for communication.

Broca’s Area

Involved in speech production.

Wernicke’s Area

Responsible for language comprehension.

Neuroplasticity

The brain’s ability to reorganize itself by forming new connections.

CT Scan

Uses X-rays to create brain structure images.

MRI

Uses magnetic fields to capture high-resolution brain structures.

fMRI

Detects brain activity via oxygen changes in blood flow.

PET Scan

Tracks glucose use to identify active brain regions.

EEG

Measures electrical activity in the brain through scalp electrodes.

Sensation

The detection of physical energy (stimuli) by sensory organs.

Perception

The process of organizing and interpreting sensory information.

Psychophysics

Study of how physical stimuli relate to psychological experience.

Absolute Threshold

Minimum stimulus intensity detectable 50% of the time.

Subliminal Stimuli

Below the conscious threshold of detection.

Difference Threshold (JND)

Smallest detectable difference between two stimuli.

Weber’s Law

JND is proportional to the intensity of the original stimulus.

Signal Detection Theory

Detection depends on both sensation and decision processes.

Transduction

Conversion of physical energy into neural signals.

Selective Attention

Focusing on one stimulus while ignoring others.

Inattentional Blindness

Failing to see visible objects when attention is elsewhere.

Divided Attention

Splitting focus between multiple tasks, lowering performance.

Sensory Adaptation

Reduced sensitivity after prolonged exposure.

Perceptual Constancy

Recognizing objects as stable despite sensory changes.

Priming

Prior exposure affects response to later stimuli.

Top-Down Processing

Perception shaped by experience and expectations.

Bottom-Up Processing

Building perception from raw sensory input.

Perceptual Set

Tendency to perceive based on expectations or context.

Multimodal Perception

Integration of multiple senses to create experiences.

Gestalt Principle

The idea that we perceive visual elements as organized wholes rather than separate parts; the whole is greater than the sum of its parts.