Chapter 22: Respiration

Homeostatic Imbalances and Clinical Conditions

The respiratory system is essential for gas exchange and maintaining homeostasis in the body. Various conditions can disrupt normal respiratory function, leading to clinical symptoms and disease. This section reviews key homeostatic imbalances and clinical terms relevant to the respiratory system.

Common Respiratory Conditions

• Rhinitis/Sinusitis: Inflammation of the nasal mucosa (rhinitis) or sinuses (sinusitis), often due to infection or allergies. Symptoms include congestion, runny nose, and facial pain.

• Deviated Septum: Displacement of the nasal septum, which can obstruct airflow and cause breathing difficulties.

• Infected Adenoids: Enlargement and infection of adenoid tissue in the nasopharynx, leading to airway obstruction and recurrent infections.

• Laryngitis: Inflammation of the larynx, typically causing hoarseness or loss of voice.

• Smoker's Cough: Chronic cough due to irritation of the respiratory tract from tobacco smoke.

• Heimlich Maneuver: Emergency procedure to dislodge objects blocking the airway by applying abdominal thrusts.

• Pleurisy: Inflammation of the pleura (membranes surrounding the lungs), causing sharp chest pain during breathing.

• Atelectasis/Pneumothorax: Atelectasis is the collapse of lung tissue, while pneumothorax is the presence of air in the pleural cavity, both leading to impaired gas exchange.

• Asthma: Chronic inflammatory disease causing airway constriction, wheezing, and difficulty breathing.

• IRDS (Infant Respiratory Distress Syndrome): Condition in premature infants due to insufficient surfactant, leading to alveolar collapse.

• Lung Compliance: Measure of the lung's ability to stretch and expand. Low compliance indicates stiff lungs, as seen in fibrosis.

• Thoracic Cage Deformities: Abnormalities in the structure of the chest wall that can restrict lung expansion.

• Hypoxia: Deficiency of oxygen reaching tissues, leading to cyanosis and organ dysfunction.

• Hyperventilation (Hypocapnia): Rapid breathing causing decreased carbon dioxide levels in the blood (hypocapnia), which can result in dizziness and alkalosis.

Major Respiratory Diseases

Several chronic and acute diseases affect the respiratory system, often leading to significant morbidity.

• COPD (Chronic Obstructive Pulmonary Disease): Group of progressive lung diseases characterized by airflow limitation. Includes:

  • Emphysema: Destruction of alveolar walls, reducing surface area for gas exchange.

  • Bronchitis: Chronic inflammation of the bronchi, leading to mucus production and cough.

• Asthma: (See above)

• Tuberculosis: Infectious disease caused by Mycobacterium tuberculosis, leading to granuloma formation in the lungs.

• Lung Cancer: Malignant growth in lung tissue, often associated with smoking.

• Sleep Apnea: Repeated episodes of airway obstruction during sleep, causing intermittent hypoxia and sleep disruption.

Clinical Related Terms

• Aspiration: Inhalation of foreign material (food, liquid) into the airway, which can lead to pneumonia.

• Pneumonia: Infection of the lung parenchyma, causing inflammation, fever, and difficulty breathing.

• Pulmonary Embolism: Blockage of a pulmonary artery by a blood clot, leading to sudden shortness of breath and chest pain.

• Tracheotomy: Surgical procedure to create an opening in the trachea to bypass airway obstruction.

• Cystic Fibrosis: Genetic disorder affecting chloride channels, leading to thick mucus production and chronic respiratory infections.

Table: Comparison of Major Respiratory Diseases

Key Terms and Definitions

• Hypoxia: Low oxygen levels in tissues.

• Hyperventilation: Increased rate and depth of breathing.

• Pneumothorax: Air in the pleural cavity causing lung collapse.

• Atelectasis: Collapse of part or all of a lung.

• Compliance: Ability of the lung to expand; mathematically, where is change in volume and is change in pressure.

Example: Heimlich Maneuver

The Heimlich maneuver is performed by standing behind a choking person, placing hands above the navel, and delivering quick upward abdominal thrusts to expel the obstructing object from the airway.

Additional info: Some terms and explanations have been expanded for academic completeness and clarity.