The Respiratory System Chapter 13 The Respiratory System

Respiration Function Processes conducting zone - air to lungs respiratory zone - alveoli and capillaries Processes pulmonary respiration external respiration respiratory gas transport internal respiration - alveoli

Upper Respiratory Structures The nose and nasal cavity functions humidifies “moistens” for 02 diffusion warms to speed up diffusion cleans with cilia Cleans & moistens with mucus structures nostrils - external nares nasal septum nasal cavity - houses sinuses

Paranasal Sinuses location functions problems Pharynx frontal sphenoid ethmoid maxillary functions warm moisten and clean lighten skull speech resonance problems rhinitis - inflammation of nasal mucosa sinusitis - inflammation of sinuses Pharynx 5 inch muscular pathway for food and air Uvula – flap which covers the nasal opening when swallowing tonsils

Lower Respiratory System Larynx “ voice box” epiglottis - flap closes when you swallow glottis - slit like passage between vocal cords vocal folds – vibrate for voice production Thyroid cartilage- “Adam’s apple” Trachea windpipe 4 inches lined w/ cilia , mucus, pseudostratified C shaped rings of cartilage Heimlich manuever tracheostomy - surgical opening

Bronchi bronchioles right & left branch into each lung bronchial tubes alveolar sacs – alveoli surrounded by capillaries

Breathing or Ventilation Factors Involved - 12-15breaths / min inspiration - air in expiration – air out MRV 6 L / min TV 500 ml / breath atmospheric pressure intrapleural pressure Boyle’s Law pressure of a gas varies inversely w/ volume

Inspiration Expiration air going in sequence ribs move up and out diaphragm moves down “Contracts” larger chest cavity volume up pressure drops air goes in Expiration passive process relaxation of inspiratory muscles ribs down and in diaphragm relaxes moves up smaller chest cavity volume down pressure up air goes out abdominal muscles help force out air

Nonrespiratory Air Movements cough forces glottis open Sneeze- air out thru nasal cavities crying & laughing short inspirations hiccups spasms of diaphragm - phrenic nerve yawn deep inspiration

Air Volumes and Capacities Spirometer * measures respiratory capacity tidal volume * TV 500 ml , normal breathing inspiratory reserve volume forced inhalation 2100 - 3100 ml expiratory reserve volume air forced out 1200 ml residual volume * 1200 ml , keep lungs & alveoli inflated inspiratory capacity TV & IRV = 3600 ml expiratory capacity TV & ERV = 1700 ml

functional residual capacity vital capacity * total lung capacity 2400 ml vital capacity * total amount of exchangeable air 4800 ml total lung capacity 6000 ml TV + IRV + ERV + RV anatomical dead space 150 ml air in conducting passways

Respiratory Sounds bronchial rales wheezing air rushing in rasping whistling

Respiratory Disorders COPD chronic obstructive pulmonary disorder features history of smoking dyspnea - labored breathing frequent coughing / infections hypoxic : retain CO2 emphysema pink puffers alveoli enlarges , air goes in hard to exhale and airways collapse chronic bronchitis blue bloaters a lot of mucus inflammation CO2 retained chronic infections

Lung Cancer 1/3 of all cancer deaths in U.S. & 90% are smokers Second leading cause of death in US squamous cell adenocarcinoma small cell carcinoma

Developmental Aspects Surfactant detergent like lipoprotein reduces water cohension & keeps alveoli sacs inflated IRDS infant respiratory distress syndrome premature babies Cystic Fibrosis oversecretion of mucus SIDS- sudden infant death syndrome Asthma chronic inflammation of bronchial passageways Others hypersensitive irritants, tuberculosis & pneumonia, sleep apnea

Gas Transport Transport of Oxygen attached to hemoglobin oxyhemoglobin temperature effect temp goes up more oxygen released into tissues pH effect pH drops more oxygen released - less hemoglobin affinity happens during exercise impairments of oxygen hypoxia not enough O2 to cells Anemia, blockage, lack of blood CO poisoning CO binds with hemoglobin

Control of Respiration Phrenic and Intercostal Nerves move diaphragm and ribs Respiratory Centers medulla - respiratory rhythm 12-18 breaths/min pons - transition from expiration to inspiration Factors influencing respiratory rate physical exercising, talking, coughing, body temp. Volition “conscious” hold breath, singing emotional excited scared, sympathetic chemical levels of CO2 and O2 and pH of blood