The brain has billions of neurons and they have many specialized jobs.

_____ send information from the eyes, ears, nose, tongue, and skin to the brain.

_____ carry messages away from the brain to the rest of the body.

_____ neurons relay information to each other through a complex electrochemical process, making connections that affect the way you think, learn, move, and behave.

As you grow and learn, messages travel from one neuron to another over and over, creating connections, or pathways, in the brain.

Neural pathways make intelligence, learning and memory possible. An example of this is why driving takes so much concentration when someone first learns it, but later is second nature. The pathway became established.

The things you've done, learned, and seen are first processed in the cortex. Then, if you sense that this information is important enough to remember permanently, it's passed inward to other regions of the brain (such as the hippocampus and amygdala) for long-term storage and retrieval.

As messages from the cortex travel through the brain, they create pathways that serve as the basis of memory.

Different parts of the cerebrum move different body parts.

The left side of the brain controls the movements of the right side of the body

The right side of the brain controls the movements of the left side of the body.

A part of the peripheral nervous system called the autonomic nervous system controls many of the body processes you almost never need to think about, like breathing, digestion, sweating, and shivering.

The autonomic nervous system has two parts: the sympathetic nervous system and the parasympathetic nervous system.

The sympathetic nervous system prepares the body for sudden stress, like if you witness a robbery. When something frightening happens, the sympathetic nervous system makes the heart beat faster so that it sends blood quickly to the different body parts that might need it. It also causes the adrenal glands at the top of the kidneys to release adrenaline, a hormone that helps give extra power to the muscles for a quick getaway. This process is known as the body's "fight or flight" response.

The parasympathetic nervous system prepares the body for rest. It also helps the digestive tract move along so our bodies can efficiently take in nutrients from the food we eat.

This sense probably tells us more about the world than any other sense. Light entering the eye forms an upside-down image on the retina. The retina transforms the light into nerve signals for the brain. The brain then turns the image right-side up and tells you what you're seeing.

This sense is the result of sound waves entering your ears and making your eardrums vibrate. These vibrations then move along the tiny bones of the middle ear and turn into nerve signals. The cortex then processes these signals, telling you what you're hearing.

This sense contains small groups of sensory cells called taste buds that react to chemicals in foods. Taste buds react to sweet, sour, salty, bitter, and savory. The taste buds send messages to the areas in the cortex responsible for processing taste.

Olfactory cells in the mucous membranes lining each nostril react to chemicals you breathe in and send messages along specific nerves to the brain.

The skin contains millions of sensory receptors that gather information related to touch, pressure, temperature, and pain and send it to the brain for processing and reaction.