Answer:

There are four types of hypoxia:

i.lood supply to the tissues is inadequate

ii.lood is unable to carry enough oxygen to the tissues

iii.nadequate amounts of oxygen entering the lungs

iv.are unable to use the oxygen reaching them

Answer:

The upper respiratory tract has:

·    Mucociliary escalator – the mucous membrane of the trachea is composed of pseudostratified ciliated columnar epithelium with numerous goblet cells (mucus producing cells) and function as a mucociliary escalator. The mucus traps inhaled debris or foreign particles, the cilia propel the mucus towards the pharynx, where it is swallowed.

·    Coughing

The lower respiratory tract has:

·    Alveolar macrophages – large particles (>10 µm in diameter) are usually trapped by the nasal hair or in the mucus of the upper respiratory tract. Smaller particles (2–10 µm in diameter) are usually trapped in the mucus of the bronchi and bronchioles and then removed by the mucociliary escalator. However, particles smaller than 2 µm can enter the alveoli, where they are phagocytosed by the macrophages.

Answer:

Pneumonia refers to infection of the pulmonary parenchyma, i.e. bronchioles and alveoli. It may develop as an acute primary infection or may occur as a secondary infection due to another respiratory or systemic condition. It occurs when the normal defence mechanisms are bypassed and a pathogen gains access to the lower respiratory tract causing an extensive inflammatory response.

Answer:

·    Young adults – male > female

·    People living in developing countries

·    Level of poverty

·    Healthcare workers who are exposed to disease on frequent basis

·    Those with compromised/weakened immune systems

·    Cancer

·    Human immunodeficiency virus (HIV) infection

·    Smoking

·    Host deficiency in IL-2 promoting T-helper 1 response (de Martino et al., 2014)

·    Foreign-born individuals living in impoverished areas

·    Undernutrition

Answer:

Signs and symptoms are not always initially apparent but may include: mild fever, cough with purulent sputum, fatigue and night sweats. As the disease progresses dyspnoea, wheezing haemoptysis, chest pain, weight loss and anorexia may become apparent.

Answer:

A pleural effusion is an abnormal collection of fluid in the pleural cavity. They can be categorised as: hydrothorax (serous fluid, transudative or exudative), empyema (pus), chylothorax (chyle) and haemothorax (blood).

Answer:

There are three different types of atelectasis: compression atelectasis, absorption atelectasis and surfactant impairment.

Answer:

The early phase response follows antigen exposure. The dendritic cells activate T-helper 2 cells to produce interleukins (ILs) IL-5, IL-4, IL-13. Eosinophils are recruited to the lung mucosa. IgE antibodies attach to mast cell surface causing them to degranulate their contents. The inflammatory mediators, such as histamine, cause vasodilation and altered capillary permeability resulting in mucosal oedema, smooth muscle contraction resulting in bronchospasm and mucous secretion. This narrows the airways and obstructs airflow. Eosinophil products cause damage to the lung epithelial tissue.

Answer:

Smooth muscle in the walls of the airways constrict and the lumen narrows increasing resistance to airflow, particularly on expiration. High airway resistance causes the airways to collapse just before expiration, trapping air in the alveoli and causing hyperinflation and non-uniform ventilation.

Answer:

The inflammatory mechanisms responsible for mucous overproduction is attributed to Th1cells and specifically the subset Th17 cells. Interleukin 6 (IL-6) and interleukin 17 (IL-17) induce the production of proteins called mucins by lung epithelial cells which contribute to thick mucus production and the formation of mucous plugs which block the airway lumen. This is consolidated by impaired mucociliary clearance due to dysfunction and loss of cilia.

Answer:

Centriacinar emphysema refers to the central or proximal parts of the acini and is associated with smokers and is often seen in COPD. Panacinar emphysema involves the acini at the terminal alveoli and is associated with α-antitrypsin deficiency, an autosomal recessive inherited disorder where there is a deficiency of the enzyme α₁-antitrypsin.

Answer:

The defective cystic fibrosis transmembrane conductance regulator (CFTCR) protein leads to impaired chloride transport which leads to increased absorption of sodium and water into the circulation. This results in the secretion of thick tenacious mucus and dehydration of the mucociliary layer which reduces ciliary mobility and leads to ineffective clearing of mucus. Airway obstruction from mucous plugs and chronic inflammation and infection result in respiratory signs and symptoms.

Answer:

PE can originate from numerous sources including deep vein thrombus (DVT) (commonly in lower extremities), tumours, fat, amniotic fluid, foreign bodies, air and sepsis.

Answer:

·    Type I (hypoxaemic): Low O₂ and normal or low PCO₂. Often from dysfunction of gaseous exchange.

·    Type II (hypercapnic): Low O₂ with high PCO₂. Often from dysfunction of alveolar ventilation.