Pulmonary System Function PDF

N111 Pathopharmacology 1 Samuel Merritt University Airway Structures Larynx Carina Mucociliary Clearance Cilia Goblet Cells Ciliated columnar epithelium Mucociliary Clearance  Lining the trachea and bronchi  Pseudostratified ciliated...

N111 Pathopharmacology 1 Samuel Merritt University Airway Structures Larynx Carina Mucociliary Clearance Cilia Goblet Cells Ciliated columnar epithelium Mucociliary Clearance  Lining the trachea and bronchi  Pseudostratified ciliated columnar epithelium  Contain cilia  Goblet cells  Mucus production  Goblet cells  Mucus producing glands  Cilia  Sweep foreign particles + mucus upward  swallowed or expectorated Cough reflex  Initiates a force/pressure to clear airway of foreign matter  Cough receptors in the carina  At the primary bronchi bifurcation Alveolar cells  Type I: epithelial structure cells  Type II: produce surfactant  Lowers surface tension  Facilitates gas exchange  Immune function  Alveolar macrophages- phagocytize foreign particles  Damaged by smoking and silica Mechanisms affecting Pulmonary Circulation  Capillary hydrostatic pressure > colloid osmotic pressure  fluid moves from capillaries to the interstitial space  If this continues fluid will move into the alveoli  alveolar edema  poor gas exchange Two alveolar processes that influence alveolar respiration Ventilation Perfusion Airway Resistance  Influenced by airway diameter & the pattern of gas flow  ↓ airway diameter  ↑ airway resistance  Affected by  Mucus  Bronchospasm  Stress  Pulmonary conditioning  Age  Effects work of breathing Expiration mechanism  Lungs deflate passively  Functional residual capacity Inspiration mechanism chest wall muscles contract  elevating the ribs as the diaphragm moves downward  creating a negative intrapleural pressure Autonomic nervous system control Parasympathetic Sympathetic stimulation stimulation Vagus releases Activated β2- acetylcholine  adrenergic receptors muscles constrict   muscles relax  bronchoconstriction bronchodilation &  &  RR RR Neurologic Control of Ventilation Respiratory center in the brainstem  Pneumotaxic center  Central chemoreceptors Peripheral chemoreceptors Baroreceptors Proprioceptors  Baroreceptors & Peripheral Chemoreceptors  Located in aortic arch & carotid bodies Baroreceptors Peripheral Chemoreceptors  Respond to changes in  Respond to BP  decrease in arterial O2  Increase in hydrogen ion ↑ BP  inhibition of concentration ( pH) inspiration  Arterial carbon dioxide level (PaCO2) ↓ systolic BP (