Group+4-+execratory+system

sweat
 * the body sweats in order to cool itself off
 * nerves in the skin send a signal to the brain when they feel a temperature that is too high. the brain then sends a response back activating the sweat glands. Sweat is secreted from the sweat glands, absorbing body heat as it evaporates, therefore cooling the body down
 * parts of the skin
 * epidermis- outer protective layer without blood vessels
 * dermis- inner layer with blood vessels, sensory nerve endings, sweat and oil glands, hairs, and fat cells
 * water
 * the body needs water in order to function. we are over 95% water. Water is the main component of blood and without it, the blood gets thicker and harder to pump, therefore blood pressure drops significantly. When we sweat, we lose substantial amounts of water that must be replenished in order for the body to function.
 * salt
 * we also lose a lot of salt when we sweat. It is one of the main extracellular electrolyte is responsible for regulating water balance, pH, and osmotic pressure. This is why sports drinks (i.e. Gatorade) have salt in them. It helps improve performance.