Central Nervous System - The part of the nervous system that includes the brain and the spinal cord.
Peripheral Nervous System - The section of the nervous system that includes the nerves that relay impulses to and from the brain.
Somatic Nervous System - the part of the peripheral nervous system that controls voluntary movements.
Autonomic Nervous System - the part of the peripheral nervous system that controls body functions that are not performed consciously.
- The parasympathetic nervous system conserves energy by relaxing the digestive tract and slowing the heart rate.
- The sympathetic nervous system stimulates the body's "fight or flight" response.
Sensory Neuron - Neurons that convert stimuli from the environment into impulses to deliver to the brain.
Interneuron - Neurons that transmit impulses from one neuron to another.
Motor Neuron - Neurons that control muscles, organs or glands.
Neuromuscular Junction - The connector between a neuron and a muscle fiber.
Acetylcholine - A chemical that is released by neurons to send signals to other cells.
Norepinephrine - A chemical that is used to transmit a message from a neuron. It is used to ready the body for action.
Epinephrine - A hormone which is produced by the adrenal gland. It is more commonly called adrenaline and it plays a key role in the "fight or flight" response.
Synapse - A junction which connects two nerve cells.
White Matter - The white parts inside the brain. It affects brain functions.
Gray Matter - The gray parts on the outside of the brain. It contains most of the neurons in the brain.
Cerebral Cortex - The outer part of the cerebrum that consists of folded gray matter.
- The lobes of the brain include the frontal lobe, which is related to dopamine and emotions, the parietal lobe, which deals with language and the sense of touch, the occipital lobe, which processes what our eyes see, and the temporal lobe, which retains memories.
Limbic System - A system in the brain that supports emotion and the formation of memories.