respiratory system. main functions: provide oxygen to cells eliminate carbon dioxide works closely...
TRANSCRIPT
Respiratory System Main functions:
Provide oxygen to cells Eliminate carbon dioxide
Works closely with cardiovascular system to accomplish gas exchange
Gas exchange occurs in lungs
Upper Respiratory Passageways Air enters through nose, past sinus
cavities Air then passes through pharynx Pharynx divided into three regions:
Nasopharynx (upper) Oropharynx (middle) Laryngeal (lower)
Lower Respiratory Passageways and Lungs
Pharynx conducts air into trachea, through larynx and glottis
Epiglottis prevents food from entering respiratory tract
Larynx contains vocal cords (allows speech) Trachea divides into bronchus
Smallest tubes = bronchioles Alveoli = microscopic air sacs where gas exchange
occurs
Breathing Ventilation made up of:
Inspiration Phrenic nerve stimulates diaphragm to
contract and flatten Chest cavity enlarges Change in pressure causes air to be
pulled in Expiration
Breathing muscles relax Lungs return to original size Air forced out
Gas Transport Oxygen in blood
Attached to hemoglobin in red blood cells
Released to cells as needed
Carbon dioxide mostly as carbonic acid Amount formed regulates blood pH
Clinical Aspects of Respiration
Pulmonary function affected by conditions that: Cause resistance to air flow Limit proper expansion of chest
Conditions directly affecting respiratory system: Infection Injury Allergy Aspiration Cancer
Changes in Ventilation Changes in ventilation affect pH of blood
Alkalosis = too much carbon dioxide exhaled by hyperventilation (blood too alkaline)
Acidosis = too little carbon dioxide exhaled by hypoventilation (blood too acidic)
Infections Pneumonia
Caused by several different microorganisms Leading cause of death in debilitated
patients Tuberculosis
Caused by Mycobacterium tuberculosis Symptoms:
Fever Weight loss Weakness Cough Hemoptysis (sputum with blood)
Influenza Viral disease of respiratory tract
Emphysema Overexpansion and destruction of
alveoli Causes:
Exposure to cigarette smoke or pollution
Chronic infection Classified under chronic
obstructive pulmonary disease (COPD) heading
Asthma Narrowing of bronchial tubes Main factor may be irritation caused by
allergy Symptom of wheezing indicated by:
Constriction of bronchial tubes Edema of bronchial linings Accumulation of mucus
Extreme “attacks” may result in: Dyspnea Cyanosis
Disorders of Pleura
Pleurisy = inflammation of pleura, usually with infection Main symptom is pain which causes rapid, shallow
breathing Accumulation of substances between layers
of pleura lead to other conditions: Pneumothorax Empyema Hemothorax Hydrothorax
Fluids removed by thoracentesis
Lung Cancer
Leading cause of cancer-related deaths Usually cannot be detected early Metastasizes rapidly
Major risk factors: Cigarette smoking Other forms of cancer
Diagnosed by: Radiographic studies CT scans Sputum examination Bronchoscope
Respiratory Distress Syndrome
Occurs in premature infants Results from lack of surfactant in lungs Acute respiratory distress syndrome
May result from: Trauma Allergic reactions Infection Other causes
Involves edema that can cause respiratory failure
Diagnosis
Methods for diagnosing respiratory disorders: Radiographs CT scans MRI scans Lung scans Bronchoscopy Tests of pleural fluid removed with
thoracentesis
Methods for diagnosing respiratory disorders
Examination of arterial blood gasesEvaluating gas exchange, it measures: Carbon dioxide Oxygen Bicarbonate Blood pH
Pulse oximetry: Measure oxygen saturation of arterial blood
Pulmonary function tests: Spirometer measures volume of air moved with varying degrees of effort