The Effects of Lung Disease Flashcards
Describe what pulmonary fibrosis is
The formation of lung tissue in the lungs
This can result in the infection or exposure to substances like asbestos or dust
Scar tissue is thicker snd less elastic than normal lung tissue
The lungs are less able to expand and so can’t hold as much air as normal so the tidal volume is reduced. Its also harder to force air out of the lungs due to the loss of elasticity.
Theres a reduction in the rate of gaseous exchange = diffusion is slower across a thicker scarred membrane.
What are the symptoms of pulmonary fibrosis?
shortness of breath,
a dry cough,
chest pain,
fatigue and weakness,
They have a faster breathing rate than normal
Describe what asthma is and what happens during an asthma attack
A respiratory condition where the airways become inflamed and irritated.
The causes vary but its usaully because of an allergic reaction
During an asthma attack, the smooth muscle lining the bronchioles contracts making it narrower and a large amount of mucus is produced.
This causes a constriction of the airways making it diffilcult for the sufferer to breathe properly. Air flow in and out of the lungs is severely reduced, so less oxygen enters alveoli and moves into the blood.
What are the symptoms of asthma?
wheezing, a tight chest and shortness of breath. Inhalers releasing drugs to relieve the symptoms cause the muscle in the bronchioles to relax opening up the airways.
Describe what emphysema is.
Emphysema is caused by smoking or long term exposure to air pollution.
This causes inflammation which attracts phagocytes to the area. The phagocytes produce an enzyme that breaks down elastin. Loss of elastin means the alveoli can’t recoil to expel air as well. It also leads to destruction of the alveoli walls, which reduces the surface area of the alveoli so the rate of gaseous exchange decreases.
loss in elasticity of lung tissues so lungs are unable to force out all the air from the lungs during expiration. reduces concentration gradient thus the rate of diffusion
What are the symptoms of emphysema?
shortness of breath, wheezing, and an increased breathing rate.
How is pulmonary ventilation calculated?
pulmonary ventilation = tidal volume x ventilation rate
What is the name of the bacterium which causes pulmonary tuberculosis?
mycobacterium tuberculosis
How does mycobacterium tuberculosis cause pulmonary tuberculosis?
immune system cells build a wall around the bacteria in the lungs. This forms small, hard lumps known as tubercles.
Infected tissue within the turbercles die, the gaseous exchange surface is damaged so tidal volume is decreased.
Tuberculosis also causes fibrosis which furthur reduces the tidal volume.
If the bacteria enters the blood stream they can spread to other the body.
bacteria replication may damage or destroy alveolar wall
What are the symptoms of pulmonary tuberculosis?
persistant cough,
coughing up blood and mucus,
chest pains,
shortness of breath,
fatigue,
some may have fever and some may lose weight
How is pulmonary tuberculosis transmitted?
Tb is transmitted by droplet infection
It tends to be more widespread in areas where hygiene levels are poor and where people live in crowded conditions.
It can be prevented with the BCG vaccine and can be treated with antibiotics
how does pulmonary fibrosis cause a dry, chronic cough
fibrous tissue creates an obstruction in the airway of the lungs. The body’s reflex is to remove the obstruction by coughing
how does the alveoli maintain a short diffusion pathway with the capillary beds?
two layers of cells thick.
a single layer of flattened epithelial cells (the alveolar wall)
a single layer of endothelial cells - the capillary wall
how is a high diffusion gradient maintained for gaseous exchange?
circulatory system - by transporting deoxygenated blood to the lungs and removing oxygenated blood from the lungs
ventilation - continually providing air with high oxygen concentration and removing air with a high carbon dioxide concentration
How is the alveoli adapted for gas exchange?
Fluid lining the alveolus allows gas to dissolve and diffuse across
Only two cell lays
Blood capillaries surrounds each alveolus providing large surface area
Circulatory system maintains high diffusion gradient
Ventilation mechanism maintains a high diffusion gradient
