Biology 6: Respiratory System Pleurae Membranes Air Pathway Nares of nose: Nostrils Trachea: Food / air travels through. Air is warmed / humidified. Vibrissae filter Air ONLY. Epiglottis covering. Contains vocal cords Ciliated epithelium collect debris Bronchi: Ciliated epithelium collect debris Pharynx: Larynx: Bronchioles: Alveoli: The smallest of the branches of the bronchi Sacs where diffusion occurs. Surfactant REDUCES surface tension. Prevents collapse Pulmonary Veins, + O2 LUNGS Pulmonary Artery, - O2 Inhalation Negative pressure breathing Active process Diaphragm & External Intercostal muscles contract Spirometer Measures lung capacity CAN NOT measure TOTAL volume Total Lung Maximum volume of air in the lungs. Capacity: Residual Residual after exhalation (air stays in lungs to Volume: keep alveoli from collapsing). Vital Capacity: Difference between minimum and maximum volume of air in the lungs. Tidal Volume: Volume inhaled and exhaled in a normal breath. Expiratory Volume of additional air that can be forcibly Reserve Volume: exhaled following normal exhalation. Inspiratory Volume of additional air that can be forcibly Reserve Volume: inhaled following normal inhalation. !intrapleural space, !thoracic cavity, ¯pressure !lung volume, ¯lung pressure Air rushes in Exhalation Passive process Muscles relax ¯lung volume, !lung pressure Air leaves lungs Active Exhalation: Internal intercostal & abdominal muscles help force air out Protection from Pathogens Vibrissae: In pharynx Mucous Membranes Mucociliary Escalator Lysozymes: In nasal cavity/saliva. Attack Gram + peptidoglycan Mast Cells: Antibiotics on surface. Inflammation. Allergic reactions Bicarbonate Buffer Medulla Oblongata CO2 (g) + H2O (l)⇌ H2CO3 (aq)⇌ H+ (aq) + HCO3- (aq) ! [CO2]Þ Hypercarbia / hypercapria !respiration (exchanging gases) ¯ [O2] Þ Hypoxemia !ventilation (air in/out) ¯pH Þ !respiration to blow off CO2 !pH Þ ¯respiration, trapping CO2