Science+0

10/1/2009 Excretory System

Excretion: The removal of wastes from a living thing.

Wastes produced in our body: carbon dioxide, inorganic salts, heat, water, nitrogen

Organs of the Excretory System: Lungs, Kidneys, Liver, Skin

9/24/2009 --- Nervous System

Central Nervous System
 * Brain - gets and sends signals around the body; Major Control Center of Body
 * Spinal Cord - is protected by spine; connects the brain to the rest of the nervous system

Peripheral Nervous System Voluntary Actions
 * Nerves - Travel through body; connect the spinal cord to sensors throughout the body
 * Things you think about doing --- juggling, walking, reading, bike riding

Autonomic (Involuntary Actions)
 * Things that you don't think about doing breathing, response to danger, blinking

Brain Cerebrum Cerebellum
 * Most important part of our body
 * Protected by skull and three layers of tissue
 * two halves -- Right side is creativity, music, art; Left side is math, logic, speech, writing
 * Right side of brain controls left side of body; Left side of brain controls right side of body


 * Balance
 * Muscle Coordination

Medulla
 * Controlls heartbeat, breathing