1. Respiratory System

2. 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

3. Respiratory System

5. 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)

6. 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

12. 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

13. Pulmonary Ventilation

14. Gas Transport Oxygen in blood Carbon dioxide mostly as carbonic acid
Attached to hemoglobin in red blood cells
Released to cells as needed
Carbon dioxide mostly as carbonic acid
Amount formed regulates blood pH

15. 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

16. 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)

17. Infections Pneumonia Tuberculosis Influenza
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

18. Emphysema Overexpansion and destruction of alveoli Causes:
Exposure to cigarette smoke or pollution
Chronic infection
Classified under chronic obstructive pulmonary disease (COPD) heading

19. 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

20. 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

21. Lung Cancer Leading cause of cancer-related deaths Major risk factors:
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

22. 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

23. Diagnosis Methods for diagnosing respiratory disorders: Radiographs
CT scans
MRI scans
Lung scans
Bronchoscopy
Tests of pleural fluid removed with thoracentesis

24. Methods for diagnosing respiratory disorders
Examination of arterial blood gases
Evaluating 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