Overview
The respiratory system moves air into and out of the lungs and supports gas exchange, supplying oxygen to the blood and removing carbon dioxide.
It works closely with the cardiovascular system to deliver oxygen to tissues and remove waste gases.
The respiratory system also helps regulate blood pH, enables speech, and protects the body from inhaled particles and pathogens.
Major Structures
Upper Respiratory Tract
- Nose and Nasal Cavity: Filter, warm, and humidify inhaled air.
- Pharynx (Throat): Passageway shared by air and food.
- Larynx (Voice Box): Contains the vocal cords and helps protect the lower airway during swallowing.
- Epiglottis: Flap of cartilage that helps prevent food and liquids from entering the airway during swallowing.
Lower Respiratory Tract
- Trachea (Windpipe): Conducts air toward the lungs; supported by cartilage rings.
- Bronchi: Two main branches of the trachea that carry air into the lungs.
- Bronchioles: Smaller branching airways that distribute air to the alveoli.
- Alveoli: Tiny air sacs where oxygen enters the blood and carbon dioxide leaves it.
- Lungs: Organs containing branching airways and alveoli, where gas exchange occurs.
- Pulmonary Capillaries: Tiny blood vessels surrounding the alveoli, allowing oxygen and carbon dioxide exchange.
Supporting Structures
- Diaphragm: Primary muscle responsible for inhalation; contracts and moves downward, increasing chest cavity volume.
- Intercostal Muscles: Muscles between the ribs that assist with breathing.
- Pleura: Thin membranes covering the lungs and lining the chest cavity, allowing smooth movement during breathing.
- Cilia: Microscopic hairlike structures lining much of the respiratory tract that move mucus and trapped particles toward the throat.
Key Processes
- Ventilation: Movement of air into and out of the lungs.
- Inhalation (Inspiration): The diaphragm contracts and moves downward, expanding the chest cavity and drawing air into the lungs.
- Exhalation (Expiration): The diaphragm relaxes, and elastic recoil helps move air out. Forced exhalation also uses additional muscles.
- Gas Exchange: Oxygen diffuses from the alveoli into pulmonary capillaries, while carbon dioxide diffuses from the blood into the alveoli.
- Oxygen Transport: Hemoglobin in red blood cells carries most oxygen from the lungs to body tissues.
- Carbon Dioxide Removal: Carbon dioxide produced by cells is transported to the lungs and exhaled.
- Respiratory Regulation: The brainstem adjusts breathing based on chemical signals, especially carbon dioxide levels and blood pH.
- Airway Protection: Mucus, cilia, and coughing help remove inhaled particles and pathogens.
- Acid-Base Regulation: Breathing helps regulate blood pH by controlling carbon dioxide removal.
Effects of Aging
- Reduced Respiratory Muscle Strength: The diaphragm and other breathing muscles may become less effective.
- Reduced Chest Wall Flexibility: Changes in the ribs, spine, and connective tissues can restrict chest expansion.
- Reduced Lung Elasticity: Lung tissue loses some elastic recoil, potentially increasing air trapping.
- Reduced Respiratory Reserve: The lungs may be less able to compensate during physical exertion or illness.
- Less Effective Airway Clearance: Changes in cough reflexes and mucus clearance can make secretions harder to remove.
Clinical Implications
- Respiratory infections, such as pneumonia, may be harder to tolerate.
- Physical activity may cause fatigue or breathlessness more readily.
- Immobility can increase the risk of secretion buildup and respiratory complications.
- Observe respiratory rate, breathing effort, cough, and changes from baseline.
- Encourage permitted mobility and positioning according to the care plan.
Important: Significant shortness of breath, low oxygen levels, or new respiratory distress should not be dismissed as normal aging.
Common Diseases & Disorders
| Condition | Description | Common Causes / Risk Factors | CNA Considerations |
|---|---|---|---|
| Chronic Obstructive Pulmonary Disease (COPD) | Chronic airflow limitation, commonly involving emphysema and chronic bronchitis. Emphysema damages alveolar walls; chronic bronchitis causes airway inflammation and excess mucus. | Smoking, long-term exposure to air pollutants, occupational dust or fumes, rarely genetic conditions | Observe dyspnea, wheezing, chronic cough, sputum production, fatigue, and changes in respiratory effort. Follow prescribed positioning, activity, and oxygen-safety instructions. |
| Asthma | Chronic airway inflammation with episodes of airway narrowing, often causing wheezing, coughing, and shortness of breath | Allergens, smoke, respiratory infections, exercise, cold air, strong fragrances; genetic susceptibility | Recognize and report breathing difficulty, wheezing, coughing, or worsening symptoms. Assist with prescribed care within CNA scope. |
| Tuberculosis (TB) | Bacterial infection caused by Mycobacterium tuberculosis, usually affecting the lungs. Active pulmonary TB can cause prolonged cough, fever, night sweats, and weight loss. | Airborne exposure to a person with infectious TB; increased risk with weakened immunity and certain congregate settings | Report suspected symptoms or exposure promptly; follow airborne precautions and facility protocols, including a negative-pressure room. |
| Pneumonia | Infection of lung tissue that causes inflammation and may fill alveoli with fluid or inflammatory material, impairing gas exchange | Bacterial, viral, or fungal infection; aspiration, older age, impaired immunity, immobility | Observe cough, fever, increased respiratory effort, fatigue, and new confusion or functional decline. Report changes promptly. |
| Acute Bronchitis | Inflammation of the bronchi, commonly causing cough and sometimes mucus production | Usually respiratory viruses; smoke and other airway irritants | Observe cough, sputum, fever, and breathing changes. Report worsening symptoms. |
Important: CNAs observe and report respiratory abnormalities rather than independently diagnosing conditions, prescribing oxygen, or selecting treatments.
Important Distinctions
- Emphysema vs. Chronic Bronchitis: Emphysema involves destruction of alveolar walls and loss of elastic recoil. Chronic bronchitis involves chronic productive cough associated with airway inflammation and mucus production. Both may contribute to COPD.
- Asthma vs. COPD: Asthma commonly involves variable airway narrowing and inflammation, often with substantial reversibility. COPD causes persistent airflow limitation, although symptoms and treatment responses can vary. Some patients have features of both.
- Ventilation vs. Gas Exchange: Ventilation moves air into and out of the lungs. Gas exchange transfers oxygen and carbon dioxide between the alveoli and pulmonary capillaries.
- Hypoxemia vs. Hypoxia: Hypoxemia means reduced oxygen in arterial blood. Hypoxia means inadequate oxygen availability or use at the tissue level. They are related but not identical.
When to Report
- New or worsening shortness of breath.
- Increased respiratory rate, effort, or unusual breathing patterns.
- Persistent or worsening cough.
- New or increased sputum production or changes in its appearance.
- Fever or symptoms suggesting a respiratory infection.
- New confusion, unusual fatigue, or reduced activity tolerance.
- Oxygen saturation outside the resident’s prescribed parameters, when monitoring is part of the care plan.
Emergency signs: Severe difficulty breathing, inability to speak because of breathlessness, blue or gray lips or skin, sudden unresponsiveness, or signs of complete airway obstruction require immediate emergency response.
Study Notes
Clinical Connections
- Recognizing Patient Distress: Changes in breathing may indicate respiratory compromise or acute illness.
- Choking & Airway Obstruction: Obstruction prevents adequate airflow and requires prompt recognition.
- Cardiac Arrest & CPR Response: Inadequate breathing or circulation can require immediate emergency intervention.
- Patient Positions: Upright positioning, when appropriate, can improve comfort and ease breathing.
- Transmission-Based Precautions: Respiratory infections require appropriate transmission-based precautions.
Questions
- What distinguishes the upper and lower respiratory tracts?
- What is the role of the alveoli and pulmonary capillaries?
- What happens to the diaphragm during inhalation and exhalation?
- What is the difference between ventilation and gas exchange?
- How do mucus and cilia protect the respiratory tract?
- How does aging affect respiratory reserve and airway clearance?
- What distinguishes emphysema from chronic bronchitis?
- How do asthma and COPD differ?
- How is active pulmonary tuberculosis transmitted?
- Why can pneumonia impair oxygen exchange?
- What respiratory changes should a CNA report immediately?
Sources
- CNA Module 13 — Anatomy, Physiology & Aging
- MedlinePlus — Aging Changes in the Lungs
- NIH — Chronic Obstructive Pulmonary Disease
- CDC — Tuberculosis
Flashcards
What is the primary function of the respiratory system?01-foundations / anatomy-physiology / respiratory
Answer
Supply oxygen to the blood and remove carbon dioxide.
What is the function of the nasal cavity?01-foundations / anatomy-physiology / respiratory
Answer
Filter, warm, and humidify inhaled air.
Where does oxygen and carbon dioxide exchange occur in the lungs?01-foundations / anatomy-physiology / respiratory
Answer
Across the alveoli and surrounding pulmonary capillaries.
What happens to the diaphragm during inhalation?02-mechanisms / anatomy-physiology / respiratory
Answer
It contracts and moves downward, increasing chest cavity volume.
What happens to the diaphragm during normal exhalation?02-mechanisms / anatomy-physiology / respiratory
Answer
It relaxes and moves upward as air leaves the lungs.
What is the difference between ventilation and gas exchange?02-mechanisms / anatomy-physiology / respiratory
Answer
Ventilation moves air; gas exchange transfers oxygen and carbon dioxide between alveoli and blood.
What is the function of cilia in the respiratory tract?01-foundations / anatomy-physiology / respiratory
Answer
Move mucus and trapped particles toward the throat for removal.
What carries most oxygen through the bloodstream?01-foundations / anatomy-physiology / respiratory
Answer
Hemoglobin in red blood cells.
How does aging commonly affect the respiratory system?02-mechanisms / anatomy-physiology / respiratory
Answer
Reduced chest-wall flexibility, respiratory reserve, and airway clearance.
What is the difference between chronic bronchitis and emphysema?02-mechanisms / anatomy-physiology / respiratory
Answer
Chronic bronchitis involves airway inflammation and excess mucus; emphysema damages alveolar walls.
What happens to the airways during an asthma attack?02-mechanisms / anatomy-physiology / respiratory
Answer
Airways narrow due to inflammation and tightening of surrounding smooth muscle.
How does active pulmonary tuberculosis spread?02-mechanisms / anatomy-physiology / respiratory
Answer
Through airborne particles released by a person with infectious TB.
Why does pneumonia impair gas exchange?02-mechanisms / anatomy-physiology / respiratory
Answer
Inflammation and fluid or other material in the alveoli interfere with oxygen transfer.
What is a common cause of acute bronchitis?02-mechanisms / anatomy-physiology / respiratory
Answer
Respiratory viral infections.
What should a CNA do if a resident develops sudden severe breathing difficulty?03-application / anatomy-physiology / respiratory
Answer
Activate the facility's emergency response and summon immediate help.