Respiratory - Class 3 Flashcards
An acute infection of the bronchial tree, causing inflammation of medium and large sized bronchi and trachea.
Acute Bronchitis
Bronchial mucosal irritation, hyperemia and edema leads to diminished bronchial mucociliary function.
Acute Bronchitis
Airways can become blocked, clogged by debris and irritation increases secretion of mucus, leading to coughing.
Acute Bronchitis
Commonly related to bacterial infection but may be viral, allergic or caused by exposure to toxins/pollutants.
Acute Bronchitis
Often associated with smoking, or being immune-suppressed (specifically seen in young children and with advanced age).
Acute Bronchitis
Usually self-limiting (lasting approximately 10 days) and if bacterial, can be effectively treated with antibiotics. If the inflammation extends into the bronchioles and alveoli, bronchopneumonia results.
Acute Bronchitis
Recurrence can damage mucosa, mucociliary elevator, leading to impairment of the removal of mucous and particles, and can contribute to bronchial epithelial metaplasia (cancer).
Acute Bronchitis
Productive intense cough: sputum is clear, yellow, green (occasionally blood-tinged)
Acute Bronchitis Signs & Symptoms
this is associated with an abnormal reaction of the lungs to inhaled noxious particles/gases, and there are 3 main different types (emphesyma, bronchiectasis & chronic bronchitis).
COPD
COPD
Chronic Obstructive Pulmonary Disease
there is a progressive, chronic or recurrent airflow limitation, often leading to prolonged forced exhalations and predominately irreversible damage to lungs.
COPD
Pathological changes in COPD occur mainly in the ______ ______ and the small bronchioles. Lung parenchyma can also be affected.
large airways
- inflammation and edema of lung mucosa
- thickened basement membrane
- mucus gland hypertrophy
- goblet cell hyperplasia
- bronchial smooth muscle hypertrophy/ constriction
- airway wall remodelling (chronic inflammation will result in thickening of the mucosa)
Pathological features of COPD
Destruction of alveolar walls and capillary beds supplying the alveoli - leading to abnormal, permanent enlargements of the air spacesdistal to the terminal bronchioles, distention and expansion of the airspaces/ alveoli into larger air sacs – inefficient for gas exchange
Emphysema
Damage to elastic fibres that function to hold airways open - leads to loss of lung elastic recoil and impaired gas exchange. During expiration (especially forced expiration), small airways collapse and air is trapped in the lungs distal to the collapsed airways.
Emphysema
Lung compliance increases (the lung becomes easy to distend), but recoil is decreased so the airway empties slowly. As the patient exhales, the airways begin to collapse before the air has been expelled, resulting in a chronically over-inflated lung. This can affect the diaphragm function and the patient is faced with the increasingly difficult task of constantly trying to expand an already over-expanded thorax…
Emphysema
Abnormal enlargements of air spaces distal to the terminal bronchioles are known as BULLA. Once they have enlarged to greater than 1 cm (they may reach sizes of greater than 7 cm in some cases), bulla may compress adjacent healthy lung tissue, further impairing ventilation and perfusion.
How does emphysema develop
In cases of advanced emphysema, bulla may be surgically removed, both to reduce compression and avoid their “bursting”, which could lead to a ___________.
Pneumothorax
- smoking (primary and secondary smoke)
- small percentage related to genetic defects in the structure of the respiratory unit
- repeated respiratory infections (especially chronic bronchitis)
- atmospheric pollution
Causes of Emphysema
Centriacinar (Centrilobular) & Panacinar (Panlobular)
Types of Emphysema
- focal destruction of respiratory bronchiole and the central portions of acinus with edema, inflammation and thickening of the bronchiolar wall
- most common in upper lobes
- rare in non-smokers, almost exclusively disease of smokers
- begins at alveolar duct
Centriacinar (Centrilobular)