Unit 1.2 - Overview of the Nervous System

AP Psychology vocabulary from collegeboard.

Nervous System

The ultimate communication network in your body — managing everything from your reaction time to your heartbeat.

Levels of the Nervous System

Nervous system → Central Nervous System and Peripheral Nervous System

Peripheral nervous system → Autonomic and Somatic

Autonomic → Sympathetic and Parasympathetic

The Central Nervous System components

The brain and spinal cord

The Central Nervous System function

Acts as the command center — processing information and sending instructions throughout the body

Reflexes definition

Reflexes are automatic responses to stimuli, like pulling your hand away from a hot stove

Reflexes role

Reflex actions are quick because the signals travel only to the spinal cord and back, skipping the brain for speed

The Peripheral Nervous System components

All the nerves outside the brain and spinal cord

The Peripheral Nervous System function

Connects the CNS to the rest of the body — like the highways and back roads that connect cities

The Somatic Nervous System function

Controls voluntary movements of skeletal muscles. Think of it as your personal driver’s seat — when you decide to move, it’s the somatic nervous system at work.

The Autonomic Nervous System function

Controls involuntary actions like heartbeat, digestion, and breathing — basically all the stuff you don’t think about but can’t like without

The Sympathetic Nervous System function

Prepares your body for action in stressful situations — like when you’re startled, your heart races, and your palms sweat

The Sympathetic Nervous System key responses

Fight or Flight

Increases heart rate, dilates pupils, and releases adrenaline.

The Parasympathetic Nervous System function

Calms the body down after a stressful event. It’s like hitting the “chill button” to slow your heart rate and conserve energy

The Parasympathetic Nervous System key responses

Rest and Digest

Slows the heart rate, increases digestion, and relaxes muscles