Unit 1 The Lungs and disease Flashcards
What are the symptoms of pulmonary tuberculosis?
Persistent cough, coughing up blood and mucus, chest pains, shortness of breath and fatigue.
(Sufferers can be asymptomatic - infected but don’t show any symptoms as infection in inactive form)
What are fibrosis, asthma and emphysema and how do they affect lung function?
Fibrosis - the formation of scar tissue, due to exposure of substances like asbestos or dust. Scar tissue is thicker and less elastic than normal lung tissue so can’t hold as much air - tidal volume is reduced. Also reduces rate of gas exchange as diffusion is slower due to a thicker scarred membrane, so body cells receive less oxygen.
Asthma - airways become inflamed and irritated, usually due to allergic reaction. During an asthma attack, the smooth muscle lining and bronchioles contract and lots of mucus is produced. Causes constriction of the airways so it’s hard for sufferers to breathe properly, air flow is reduced so less oxygen enters the alveoli and moves into the blood, so body cells receive less oxygen and the rate of aerobic respiration in cells is reduced.
Emphysema - this is a lung disease caused by smoking or long-term exposure to air pollution, foreign particles in the smoke become trapped in the alveoli, attracting phagocytes to the area. This causes inflammation attracting phagocytes to the area, they break down the protein elastin. This loss of elastin means the alveoli can’t recoil to expel air as well leading to destruction of the alveoli walls reducing the surface area of the alveoli. This reduces the rate of gaseous exchange in the alveoli, this lack of oxygen leaves sufferers feeling tired and weak.
What is the cause of tuberculosis?
When someone becomes infected with tuberculosis (transmitted by droplet infection), immune system cells build a wall around the bacteria in the lungs. This forms hard lumps known as tubercles. Infected tissue within the tubercles dies so the gaseous exchange surface is damaged - tidal volume decreases.
