Overview of Brain Functions and Neurotransmitters

Amygdala

Controls emotions like fear and anger; helps you respond to threats.

Brainstem

The brain's 'life support' system; controls automatic functions like breathing and heartbeat.

Broca's Area

A brain area in charge of speech production. Damage here makes talking hard.

Cerebellum

Helps with balance, coordination, and smooth movements.

Cerebral Cortex

The brain's outer layer where thinking, decision-making, and perception happen.

Frontal Lobe

Responsible for planning, problem-solving, self-control, and decision-making.

Hippocampus

Helps you create and store long-term memories.

Hypothalamus

Controls basic needs like hunger, thirst, body temperature, and sleep. Also links to hormones.

Limbic System

A group of brain areas (including the amygdala and hippocampus) that handle emotions and memories.

Medulla

Manages critical functions like breathing, heartbeat, and blood pressure.

Motor Cortex

Controls voluntary movements, like raising your hand or kicking a ball.

Occipital Lobe

Processes visual information; helps you understand what you see.

Parietal Lobe

Handles touch, pain, temperature, and spatial awareness.

Pituitary Gland

The 'master gland' that controls hormones and regulates growth, stress, and reproduction.

Reticular Activating System (RAS)

Regulates wakefulness and attention, keeping you alert.

Somatosensory Cortex

Processes sensory input like touch, pressure, and pain.

Temporal Lobe

Processes sounds and helps with memory and understanding language.

Thalamus

The brain's 'relay station' that sends sensory signals (like vision or touch) to the right areas.

Wernicke's Area

Helps you understand spoken and written language.

All-or-Nothing Principle

A neuron either fires completely or doesn't fire at all, like flipping a light switch.

Depolarization

When a neuron becomes less negative and gets ready to send a signal.

Excitatory Neurotransmitter

Chemicals that increase the chance a neuron will fire.

Hyperpolarization

When a neuron becomes more negative, making it less likely to fire.

Inhibitory Neurotransmitter

Chemicals that reduce the chance a neuron will fire.

Multiple Sclerosis

A disease where the protective covering of neurons (myelin) is damaged, causing movement and communication problems.

Neuron

The basic building block of the nervous system; a cell that sends and receives signals.

Polarization

When a neuron is at rest, with a negative charge inside and positive outside.

Repolarization

Returning a neuron to its resting state after it fires.

Resting Potential

The state of a neuron when it's not firing; it's charged and ready to go.

Reuptake

When leftover neurotransmitters are reabsorbed by the neuron that released them.

Threshold

The level of stimulation a neuron needs to fire.

Acetylcholine

involved in voluntary movement, learning, memory, and sleep
too little causes alzheimers disease

Dopamine

involved with movement, attention, emotion, pleasure, and reward.
Too much can cause schizophrenia, too little Parkinson's disease.

Endorphins

Involved in pain relief and feelings of pleasure and contentedness

GABA

Inhibitory, calms anxiety
too much leads to seizures, tremors, insomnia, too little leads to anxiety

Glutamate

excitatory, involved in memory
too much leads to migraines and seizures

Norepinephrine

involved with alertness and sympathetic arousal (fight or flight)

Serotonin

Affects mood, hunger, sleep, and arousal
low levels lead to depression, anxiety, ocd

Substance P

transmits pain signals to the brain

Brain Scans

Tools to study the brain, like EEG and fMRI.

EEG (Electroencephalogram)

Measures electrical activity in the brain.

fMRI (Functional Magnetic Resonance Imaging)

Shows brain activity by tracking blood flow.

Corpus Callosum

Connects the left and right brain hemispheres, letting them communicate.

Left Hemisphere

Handles language, logic, and analytical thinking.

Right Hemisphere

Deals with creativity, emotions, and spatial abilities.

Split Brain Patient

Someone whose corpus callosum is cut to treat seizures; halves of the brain can't fully communicate.

Split Brain Research

Studies how each side of the brain works separately after the corpus callosum is cut.

Autonomic Nervous System

Controls involuntary functions like heartbeat and digestion.

Central Nervous System (CNS)

Made up of the brain and spinal cord; processes information.

Endocrine System

A system of glands that releases hormones into the bloodstream.

Interneuron

Neurons in the CNS that process information between sensory and motor neurons.

Motor Neuron

Sends signals from the brain to muscles, causing movement.

Parasympathetic Nervous System

Calms the body after stress; part of the autonomic system.

Peripheral Nervous System (PNS)

Connects the CNS to the rest of the body.

Sensory Neuron

Carries information from the senses to the brain.

Sympathetic Nervous System

Prepares the body for 'fight or flight' during stress.

Hormones

Chemicals released by glands that regulate body functions.

Agonist

A drug that mimics a neurotransmitter, activating its effects.

Alcohol

A depressant that slows down brain activity and body functions.

Antagonist

A drug that blocks a neurotransmitter's effects.

Caffeine

A stimulant that increases alertness by blocking calming chemicals.

Cocaine

A stimulant that increases dopamine and energy but is highly addictive.

Depressant

A drug that slows down the brain and body (e.g., alcohol).

Hallucinogen

A drug that causes sensory distortions (e.g., LSD, marijuana).

Heroin

A highly addictive depressant that slows the body and reduces pain.

Marijuana

Can act as a depressant, stimulant, or hallucinogen; affects mood and perception.

Stimulant

A drug that speeds up brain and body functions (e.g., caffeine, cocaine).