Respiration in Health and Disease

Question 1

describe emphysema

Answer 1

it is a progressive condition which leads to destruction of elastic tissue in the lines. in addition, there is irreversible distension of the respiratory bronchioles, alveolar ducts, and alveoli, reducing surface area for the exchange of gases

Question 2

describe chronic bronchitis

Answer 2

it is a progressive inflammatory disease resulting from prolonged irritation of bronchial epithelium. bronchitis has many symptoms which can prevent tissues getting all the oxygen they require such as:

• increased size and number of mucus glands which can block small airways
• oedema and other inflammatory changes which narrows passageways and restricts airflow
• fibrosis of airway walls, stiffening the airways and reducing airflow
• breathlessness caused by ventilation of the lungs becoming severely impaired, leading to a reduction in the amount of O2 in the blood.

Question 3

describe asthma

Answer 3

asthma is a common inflammatory disease of the airways associated with episodes of reversible over-reactivity of the airway smooth muscle. the mucus membrane and muscle layers of the bronchi become thickened and the mucus glands enlarge, reducing airflow in the respiratory tract. during an asthmatic attack, spasmodic contraction of bronchial muscles constricts the airway and there is excessive secretion of a thick sticky mucus, further narrowing the airway. inspiration is normal but expiation is only partial resulting in the lungs becoming hyper inflated and there is severe dyspnoea and wheezing

Question 4

describe restrictive lung diseases

Answer 4

Restrictive lung diseases are characterized by reduced lung volumes, either because of an alteration in lung parenchyma or because of a disease of the pleura, chest wall, or neuromuscular apparatus. Unlike obstructive lung diseases, including asthma and COPD, which show a normal or increased total lung capacity (TLC), restrictive disease are associated with a decreased TLC. Measures of expiratory airflow are preserved and airway resistance is normal. If caused by parenchymal lung disease, restrictive lung disorders are accompanied by reduced gas transfer, which may be marked clinically by desaturation after exercise.

Question 5

describe pneumonia

Answer 5

it is an infection of the alveoli. this occurs when protective processes fail to prevent inhaled or blood born microbes reaching and colonising the lungs.
lobar pneumonia is infection of 1 or more lobes leading to production of watery inflammatory exudate in the alveoli. this accumulates and fills the lobule which then overflows into and infects the adjacent lobules.
bronchopneumonia is when there is infection from bronco to terminal bronchioles and alveoli. as these become inflamed, fibrous exudate accumulates and there is an influx of leukocytes

Question 6

describe sleep apnoea

Answer 6

it is a sleep disorder that involves cessation or significant decrease in airflow in the presence of breathing effort. It is the most common type of sleep-disordered breathing and is characterized by recurrent episodes of upper airway collapse during sleep. These episodes are associated with recurrent oxyhemoglobin desaturations and arousals from sleep.