resp system/disorders Flashcards
function and structure of resp system
Function: • Enable gas exchanges between the blood and external environment • Purify, humidify, warm the incoming air Structures: • Nose • Pharynx • Larynx • Trachea • Bronchi & Bronchioles • Lungs • Alveoli
what is the Pleura
Two layered serous membranes cover the outer surface of the lungs
• Pulmonary (visceral) pleura covers the lung surface (inside layer)
• Parietal pleura lines the walls of the thoracic cavity (outside layer)
• Pleural fluid fills the area between layers of pleura
to allow gliding
• These two pleural layers resist being pulled apart
inspiration (breathing in)
Diaphragm and external intercostal muscles
contract → The size of the thoracic cavity increases →
External air is pulled into the lungs due to increase in
intrapulmonary volume and decrease in gas pressure
Pneumonia
• inflammation of the bronchioles and alveoli caused by an infection by bacteria or virus and sometimes fungi
• Alveoli become filled with fluid (serum and pus)
• often secondary to another condition eg COPD, influenza, post anaesthetic
• Occurs when normal defence systems are impaired
• Impaired coughing
• Damage to epithelial lining (smoking, noxious gases, infection)
• Depressed WBC activity (smoking, alcohol, anoxia)
• Young and old
• Chronic disease
• S & S:
Productive cough (painful), fever, increased HR and RR
- Aspiration pneumonia
Usually due to aspiration of vomitus
Asthma
periodic episodes of severe but reversible bronchial obstruction in persons with hypersensitive or hyper-responsive airways
• bronchospasm
• Increased capillary permeability causing odemea and increased mucus production
• Histamine release causing inflammation
- Repeated attacks of acute asthma may lead to irreversible damage to the lungs
- S&S: expiratory wheeze, cough, use of accessory muscles, anxiety, diaphoresis
- Stimuli for triggering attack include respiratory infections, exposure to cold, exercise, drugs such as aspirin, stress and inhalation of irritants like cigarette
smoke
Emphysema
• Disease of alveoli
• Caused by air becoming trapped in alveoli during expiration due to inflammation of bronchi and bronchioles
• leads to large, inflated alveolar air spaces which then
rupture and scar and lose their elasticity
• Alveoli fuse into large air spaces which reduces surface area
• 99% of cases due to smoking
• Symptoms include fatigue, dyspnoea on exertion, weight loss
Chronic Obstructive Pulmonary Disease (COPD)
COPD ( also known as COAD)is a group of common chronic respiratory disorders characterized by progressive tissue degeneration and obstruction in the airways of the lungs
- Examples include, emphysema, chronic bronchitis and chronic asthma
- Symptoms include, dyspnoea, coughing, increased pulmonary infections, hypoxia, causes irreversible and progressive damage to the lungs
Pulmonary oedema
- fluid collecting in the alveoli and interstitial which reduces the amount of oxygen diffusing into the blood because the alveoli become filled with fluid preventing gas exchange.
- Most commonly caused by left sided heart failure
- Hypoproteinemia due to kidney or liver disease where serum albumin levels are low
- Inflammation of the lungs with increased capillary permeability develops due to inhalation of toxic gases or in association with tumors
- Blocked lymphatic drainage in the lungs may cause edema with tumors or fibrosis
Pneumothorax
- Collection of air in the pleural cavity resulting in partial or complete collapse of the lung
• Can be spontanouus or caused by lung disease, tumor, tear or trauma eg stabbing, broken rib
• S &S:
Chest pain, dyspnoea, shallow respirations
• Treated with chest tube
• Haemothorax: collection of blood in pleural space
Pulmonary embolus
Sudden blockage of a pulmonary artery • Caused by blood clot, often from a DVT Risk factors : surgery, cancer, #leg, sedentary lifestyle, clotting disorders, hormone replacement, pregnancy • Shortness of breath • Chest pain • Anxiety • Tachypnoea, hypotension • Clammy skin, hypoxia
Treatment
• depends on size of clot and may include thrombolytics, warfarin,
heparin, vein filter and surgical embolectomy
Breath sounds (normal and abnormal)
Normal
• Vesicular: Lung field (Soft and low)
• Bronchial: Trachea & bronchi (hollow)
Abnormal
• Crackles (Rales):
bronchi with secretions; bubbling sound; Common with inspiration, fine or coarse
• Sonorous wheezes(Rhonchi):
Deep low pitched; Snorelike;
Caused by narrowed passages (pneumonia, bronchitis)
• Stridor: Crowing;
Partial obstruction of the larynx or trachea(croup)
• Sibilant wheezes:
High pitched, whistle-like, caused by narrowed passages (Asthma)
• Pleural friction rub;
Dry, creaking, grating
