Respiratory System
Main Gases of the Atmosphere Gas Symbol Approximate % Nitrogen N2 78.6 Oxygen O2 20.9 Carbon Dioxide CO2 0.04 Water Vapor H2O 0.46
Pressure and volume of a gas have an inverse relationship Boyle’s Law Pressure and volume of a gas have an inverse relationship P1V1=P2V2 As Volume increases pressure of the gas decreases As Volume decreases pressure increases
Practice Equations A gas occupies 12.3 liters at a pressure of 40.0 mm Hg. What is the volume when the pressure is increased to 60.0 mm Hg? A sample of gas has a volume of 12.0 L and a pressure of 1.00 atm. If the pressure of gas is increased to 2.00 atm, what is the new volume of the gas?
Boyle’s Law and Breathing Inspiration- Diaphragm contracts Lung volume increases what happens to the pressure inside the lungs? Expiration: Diaphragm relaxes- Lung volume decreases- what happens to pressure?
Boyle’s Equation PV = k (constant) Eupnea: normal, quiet breathing at a rate of 12 to 20 breaths per minute in adults. How do we breath?
Explain Inspiration (inhale) Expiration (exhale) Role of: Diaphragm, Intercostal Muscles, Ribs Volume of Lungs- Pressure inside/outside
Anatomy Nose Pharynx Larynx Trachea Primary bronchus (2) Lungs Respiratory membranes
Upper Respiratory Tract nose oral cavity throat pharynx larynx trachea
Lower Respiratory Tract Sometimes includes the larynx and trachea
Nose: warms and filters air Divided by nasal septum Separated from oral cavity by plate Lined with mucus Note location of olfactory bulb
Pharynx: Throat Muscular Tube- Contains: Tonsils Respiration only
Larynx: Voice Box Contains Thyroid cartlidge (Adams apple) Glottis and epiglottis Vocal Folds- vocal cords
Trachea: windpipe Contains Ciliated mucosa Cartilaginous rings- Tracheotomy:
Primary Bronchi (x2) Extension of the trachea Right: wider, shorter Rt- more common for obstruction
Lungs: Note differences between right and left. Why?
When You Breath enters the body through the nose or the mouth travels down the throat through the larynx (voice box) and trachea (windpipe) goes into the lungs through tubes called main-stem bronchi one main-stem bronchus leads to the right lung and one to the left lung in the lungs, the main-stem bronchi divide into smaller bronchi and then into even smaller tubes called bronchioles bronchioles end in tiny air sacs called alveoli
LUNGS- Note the Pressure Difference Pulmonary pleura Pleural cavity contains pleural fluid 3. Visceral pleura
Patient “A” presents in the ER with knife wound to the left of his thorax . Diagnosis: pneumothorax and a collapsed lung. a. Explain why the lung collapsed. b. Why only one collapsed lung? A. The lung penetrated by the knife collapsed because the intrapleural pressure became equal to the atmospheric pressure, allowing the pleural membranes to separate. b. Only the penetrated lung collapsed because it is isolated from the remaining mediastinal structures (and the other lung) by the pleural membranes. (p. 820)
Gas Exchange Driven by Diffusion Oxygen- high in lung- diffuses into blood CO2 high in blood- diffuses into lung
Respiratory System Disorders Asthma/Allergies COPD: Smoking: Smokers cough
Review Problems Page 849-50 #6, 12, 17, 18, 21