unit 7 PGU ppt Flashcards
What are the upper airways of the pulmonary system?
Nasopharynx, Oropharynx, Larynx
What are the lower airways of the pulmonary system?
Trachea, Bronchi, Terminal bronchioles
What are the gas-exchange airways in the pulmonary system?
Respiratory bronchioles, Alveolar ducts, Alveoli
What types of epithelial cells are found in the alveoli?
Type I alveolar cells (alveolar structure), Type II alveolar cells (surfactant production), Macrophages (immune protection)
What are the main functions of the pulmonary system?
- Gas exchange
- Nutrients to lung tissue
- Reservoir for left ventricle
- Filtering system (clots, air, and debris)
- Lower pressure than systemic circulation
What is the pulmonary circulation structure?
Pulmonary artery divides and enters the lung at the hila, each bronchus and bronchiole has an accompanying artery or arteriole
What comprises the alveolocapillary membrane?
Shared alveolar and capillary walls
What is the primary function of bronchial circulation?
Moistens inspired air, provides nutrients to airways, large pulmonary vessels, lymph nodes, and membranes around the lung
What are the major muscles involved in inspiration?
- Diaphragm
- External intercostals
- Accessory muscles (sternocleidomastoid, scalene muscles)
What are the mechanics of breathing?
- Ventilation of the lungs
- Diffusion of oxygen from the alveoli into the capillary blood
- Perfusion of systemic capillaries with oxygenated blood
- Diffusion of oxygen from systemic capillaries into the cells
What is the normal ventilation-perfusion ratio?
0.8
What are the determinants of arterial oxygenation?
- Hemoglobin binding
- Oxygen saturation
- Oxyhemoglobin association and dissociation
- Oxyhemoglobin dissociation curve
- Bohr effect
What is hypercapnia?
Increased carbon dioxide concentration in arterial blood
What is hypoxemia?
Reduced oxygenation of arterial blood
What is aspiration?
Passage of fluid and solid particles into the lungs
What are the types of atelectasis?
- Compression atelectasis
- Obstructive (absorption) atelectasis
- Surfactant impairment (adhesive) atelectasis
What is acute respiratory distress syndrome (ARDS)?
Acute lung inflammation and diffuse alveolocapillary injury resulting from injury or severe inflammation
What are the phases of ARDS?
- Exudative (within 72 hours)
- Proliferative (4 to 21 days)
- Fibrotic (14 to 21 days)
What are the manifestations of ARDS?
- Dyspnea and hypoxemia despite supplemental oxygen
- Hyperventilation and respiratory alkalosis
- Decreased tissue perfusion, metabolic acidosis, and organ dysfunction
What characterizes asthma?
Chronic inflammation of the airways causing bronchial hyperresponsiveness, constriction, and reversible airflow obstruction
What are the risk factors for chronic obstructive pulmonary disease (COPD)?
- Tobacco smoke
- Occupational dusts and chemicals
- Air pollution
- Factors affecting lung growth during gestation and childhood
What is chronic bronchitis?
Hypersecretion of mucus and chronic productive cough lasting at least 3 months of the year for at least 2 consecutive years
What is emphysema?
Abnormal permanent enlargement of the gas-exchange airways accompanied by destruction of alveolar walls without obvious fibrosis
What is viral croup?
Common in children from 6 months to 5 years, usually caused by parainfluenza, characterized by subglottic inflammation and edema
What is cystic fibrosis?
Autosomal recessive inherited disease affecting the lungs, digestive tract, and reproductive organs, leading to mucus plugging and chronic inflammation
