4Components of the Airway Nares (nostrils)Nasal cavityclean, warm, moisten airPharynx (throat)Larynx: contains vocal cordsTrachea: ciliated lining, cleans airBronchi enter lungsBronchioles (branches)
5Components: Lungs: Alveoli: contain many alveoli (air sacs) very large surface areaAlveoli:site of gas exchange between air and bloodsurrounded by capillariesoxygen enters the blood and carbon dioxide enters the alveoli through diffusion.
7How do we Breathe In? Diaphram contracts and moves down Rib cage moves up and outSize of the thoracic cavity increasesPressure in the lungs decreasesAir rushes into the lungs from an area of high pressure to low pressure
8How do we Breath Out? Diaphram relaxes and moves up Rib cage moves down and inSize of the thoracic cavity decreasesPressure in the lungs increasesAir rushes out of the lungs from an area of high pressure to low pressure
9What Controls Breathing Rate? Brain senses carbon dioxide levels in the bloodIf carbon dioxide levels increase, the brain signals the diaphragm to increase the rate of breathing.