Unit 1

Central Nervous System

Comprises the brain and spinal cord.

Peripheral Nervous System

Includes voluntary (Somatic) and involuntary (Autonomic) functions.

Parasympathetic

The division of the autonomic nervous system responsible for 'rest and digest' activities.

Sympathetic

The division of the autonomic nervous system responsible for 'fight or flight' responses.

Soma

The cell body of a neuron.

Dendrites

Parts of a neuron that receive signals.

Receptor sites

Locations that bind neurotransmitters on a neuron's surface.

Axon

The part of a neuron that transmits signals away from the soma.

Myelin sheath

Insulating layer around an axon that increases signal transmission speed.

Axon terminal branches/buttons

The structures at the end of axons that release neurotransmitters.

Synaptic vesicles

Small sacs that store neurotransmitters before release.

Synapse

The gap between neurons where communication occurs.

Glial cells

Support cells that assist neurons in various functions.

Sensory neuron

A neuron that receives stimuli from the environment.

Motor neuron

A neuron that initiates and transmits movement signals.

Brain plasticity

The brain's ability to adapt and reorganize itself.

Dopamine

A neurotransmitter associated with reward and movement.

Serotonin

A neurotransmitter involved in mood regulation and sleep.

Norepinephrine

A neurotransmitter that influences alertness.

Glutamate

The primary excitatory neurotransmitter in the brain.

GABA

The main inhibitory neurotransmitter in the brain.

Endorphins

Neurotransmitters that provide pain relief.

Substance P

A neurotransmitter involved in pain signaling.

Acetylcholine

A neurotransmitter important for muscle action and memory.

Ghrelin

A hormone that stimulates hunger.

Leptin

A hormone that signals satiety or fullness.

Melatonin

A hormone that regulates sleep-wake cycles.

Oxytocin

A hormone associated with bonding and social connections.

Adrenaline

A hormone involved in stress response.

Brain stem

Area of the brain responsible for survival functions.

Medulla

Part of the brain stem that controls breathing and heart rate.

Reticular Activating System

A network involved in arousal and consciousness.

Cerebellum

Brain region that coordinates movement and balance.

Cerebral Cortex

The outer layer of the brain involved in higher cognitive functions.

Corpus callosum

The structure that connects the left and right hemispheres of the brain.

Occipital lobe

Brain area responsible for processing vision.

Temporal lobe

Brain area involved in hearing and memory.

Parietal lobe

Brain region associated with sensory processing.

Frontal lobe

Brain area involved in decision-making and executive functions.

Wernicke’s area

Brain region important for language comprehension.

Broca’s area

Brain region responsible for speech production.

Somatosensory cortex

Area of the brain that processes touch sensations.

Prefrontal cortex

Part of the frontal lobe involved in planning and complex behavior.

Motor cortex

Region of the brain that initiates voluntary movements.

Thalamus

Brain structure that relays sensory information.

Hypothalamus

Brain region that maintains homeostasis.

Hippocampus

Brain structure associated with memory formation.

Amygdala

Brain region involved in emotion processing.

Pituitary gland

Gland that produces hormones regulating various bodily functions.

Circadian rhythms

Biological processes that follow a 24-hour cycle.

Beta waves

Brain activity associated with being awake.

Alpha waves

Brain activity associated with relaxed awareness.

Theta waves

Brain activity associated with light sleep.

Delta waves

Brain activity associated with deep sleep.

NREM 1

Stage of light sleep.

NREM 2

Stage of sleep characterized by sleep spindles and K-complexes.

NREM 3-4

Stages of deep sleep.

REM sleep

Stage of sleep where dreaming occurs.

Activation-synthesis theory

Theory suggesting dreams result from random brain activity.

Information-processing theory

Theory suggesting dreams aid in memory consolidation.

Sleep theories

Concepts explaining the purpose of sleep, including restorative and evolutionary theories.

Insomnia

A sleep disorder characterized by difficulty falling or staying asleep.

Narcolepsy

A sleep disorder that causes excessive sleepiness.

Apnea

A sleep disorder characterized by temporary pauses in breathing.

Sensation

The process of receiving stimulus information from the environment.

Absolute threshold

The minimum level of stimulus required to detect a sensation.

Just-noticeable difference

The minimum change in a stimulus that can be detected.

Weber’s law

Principle that the just-noticeable difference is a constant proportion of the original stimulus.

Retina

Layer in the eye that processes images.

Rods

Photoreceptors in the eye that detect low light.

Cones

Photoreceptors in the eye that detect color.

Fovea

The area of the retina responsible for sharp vision.

Lens

The eye structure that focuses light on the retina.

Optic nerve

Nerve that transmits visual information from the retina to the brain.

Blindspot

Area of the retina with no light receptors.

Bipolar cells

Neurons that transmit signals from the photoreceptors to ganglion cells in the retina.

Ganglion cells

Neurons that transmit visual information from the retina to the brain.

Trichromatic theory

Theory stating that color perception is based on three types of cones (red, green, blue).

Opponent-process theory

Theory explaining color perception through opposing color pairs.

Wavelength

The distance between peaks in a wave, associated with pitch in sound.

Amplitude

The height of a wave, associated with volume in sound.

Eardrum

Membrane that vibrates with sound waves and transmits them to the ossicles.

Ossicles

Three tiny bones in the middle ear that amplify sound.

Oval window

Membrane that transfers vibrations from the ossicles to the cochlea.

Cochlea

Fluid-filled structure in the inner ear responsible for sound processing.

Basilar membrane

Membrane in the cochlea that varies in thickness and frequency response.

Auditory cilia

Hair cells in the cochlea that detect sound waves.

Conduction deafness

Hearing loss due to problems in the outer or middle ear.

Sensorineural deafness

Hearing loss caused by damage to the inner ear or auditory nerve.

Olfactory bulb

Brain structure that relays information about smell.

Gustatory system

System responsible for processing taste information.

5 tastes

Sweet, salty, sour, bitter, umami.

Gate control theory

Theory that explains how the nervous system blocks or allows pain signals.