5Respiratory System Functions include: Supplying oxygen we inhale to the bloodRemoving carbon dioxide we exhale from the blood
6Respiratory SystemAir travels from the mouth or nose through your larynx (voice box), down your trachea (wind pipe), and then into the bronchial tubes that enter your lungs.
7Respiratory System Inside your lungs, at the ends of the bronchial tubebranches, there are millionsof alveoli. These little sacsare where gas exchangeoccurs. Small capillariesare picking up oxygen anddropping offcarbon dioxide.
8Respiratory SystemThe diaphragm is made of smooth muscle. It contracts & relaxes to help the lungs inhale & exhale. If you inhale deeply, you can feel the diaphragm contracting. When you exhale, you can feel it relaxing.
9How do you Breathe?When you inhale, the diaphragm contracts, causing the chest cavity to expand. This expansion lowers the pressure in the chest cavity below the outside air pressure. Air then flows in through the airways (from high pressure to low pressure) and inflates the lungs.When you exhale, the diaphragm muscle relaxes and the chest cavity gets smaller. The decrease in volume of the cavity increases the pressure in the chest cavity above the outside air pressure.Air from the lungs (high pressure) then flows out of the airways to the outside air (low pressure). The cycle then repeats with each breath.
11Lung Trivia Each lung is about the size of a football. The lungs fill the area from the collarbone to the bottom of the ribs.Lungs are the only organ in the body light enough to float.There are million alveoli having a total surface area of about a tennis court in an adult.If all the capillaries that surround the alveoli were unwound and laid end to end they would extend kilometers (620 miles).