XABY02 RESP, CARDIO,CANCER, GENETICS Flashcards
What kind of disease is Pulmonary Tuberculosis?
Respiratory disease
How is Pulmonary tuberculosis spread?
Spread through air by droplets released when infected person coughs/sneezes
Is pulmonary tuberculosis very contagious?
no, normally takes close contact with infected person over period of time to transmit bacteria
What happens after inhalation of Pulmonary Tuberculosis bacteria? (3)
- bacteria grow and replicate within upper regions of lungs where there is a rich oxygen supply
- Phagocytic white blood cells ingest bacteria
- Bacteria encased in structures known as tubercles (nodules)
What happens in healthy people when Pulmonary Tuberculosis bacteria is inhaled?
- in healthy people, immune system prevents TB in tubercles from developing further so bacteria are inactive and do not replicate
What happens in people with immunosuppression when Pulmonary Tuberculosis bacteria is inhaled?
- Bacteria may become activated and begin to replicate
- they may damage/destroy alveolar wall and blood capillaries
- results in fibrosis and reduction in gas exchange
- Bateria may also spread to other organs and cause damage
What are the 5 symptoms of TB?
- persistent cough (coughing up blood)
- breathing difficulties
- fatigue and loss of appetite that (leads to weight loss)
- fever and night sweats
- chest pain
Why have TB cases increased increased throughout the world?
TB bacteria have mutated to produce new antibiotic resistant strains
What is the main preventative measure for TB?
BCG vaccination made from weakened strain of TB
How effective is the BCG vaccine?
- 70-80% effective against most severe forms of TB such as TB meningitis in children
- but is less effective in preventing respiratory diseases (the more common form of TB in adults)
What are other preventative measures of TB spread?
- better education about TB, particularly the need to complete all medication courses
- isolate TB sufferers
- improved health facilities and treatments
- better nutrition to ensure immune systems not weakened
How is TB treated?
- uses antibiotics to kill bacteria
- RIFAMPICIN
- ISONIAZID
How long are the courses of antibiotics needed to completely eliminate TB from the body?
6-12 months
What is ‘Directly Observed Treatment, Short-Courses’ (DOTS)?
involves patient being monitored to ensure they complete the course of antibiotics to reduce possibility of emergence of antibiotic-resistant strains
When may surgical treatment of TB be used?
if medications are ineffective
What does surgical treatment of TB involve?
one or more ribs are removed and a diseased lung (in whole or in part) is removed)
What is asthma?
A disease affecting the bronchioles
What happens when a person with asthma comes into contact with something that irritates the bronchioles? (5)
- muscle around walls of bronchioles contract
- lining of bronchioles become inflamed and swell
- over-production of sticky mucus (by bronchiole lining)
- reduces flow of air down bronchioles therefore lower volume of oxygen reaches alveoli
- reduces concentration gradient and therefore rate of gas exchange
What is an inhaler?
contains drugs that cause walls of bronchioles to relax and widen so greater volume of air (oxygen) reaches the lungs
Why does asthma differ from other lung diseases? (2)
- surface area of alveoli and elasticity of lungs not affected
- fibrosis due to scarring does not occur
What are 4 symptoms of asthma?
- shortness of breath (constriction of bronchioles)
- wheezing noise (air passing through very constricted bronchioles)
- tightening of chest (due to improper ventilation of lungs)
- coughing (reflex to clear narrow bronchioles of any obstruction)
What is Pulmonary fibrosis?
arises from scarring of lung tissue as fibrous connective tissue forms due to disease (e.g. TB) or damage
What two things does scarring of the lungs cause?
- lining of alveoli to thicken reducing efficiency of gaseous exchange due to longer diffusion distance
- lungs to become less elastic - greatly affects ability to breathe out as relies on elastic recoil of lung tissue
Why does shortness of breath occur in sufferers of PF?
- thickened epithelial lining of alveoli increases diffusion distance, diffusion of oxygen very slow
- loss of elasticity makes ventilation (particularly expiration) difficult, hard to maintain diffusion gradient
- reduced oxygen in blood results in reduced rate of respiration, reduced production of ATP therefore less ATP for muscle contraction
Why do sufferers of PF have chronic, dry coughs?
- because fibrous tissue creates obstruction in airways of lungs
- body’s reflex is to remove obstruction by coughing
- since fibrous tissue immovable, nothing expelled so cough is dry
Why do sufferers of PF have pain and discomfort in the chest?
consequence of pressure and damage from mass of fibrous tissue in lungs and further damage due to coughing
Why do sufferers of PF have weakness and fatigue?
result from reduced intake of oxygen into blood - rate of respiration decreases so less energy released - leads to fatigue
What is emphysema?
disease caused by progressive destruction of walls of alveoli leading to development of larger air spaces
What is emphysema caused by?
mainly by smoking, although air pollution may also be a factor
How does emphysema lead patient to become breathless even with minimum exercise?
- development of larger air spaces reduces surface area of alveoli
- alveolar walls become damaged and thicken
- gas exchange far less efficient due to reduced surface area and increased diffusion pathway
- loss in elasticity of lung tissue (due to loss of elastin) so lungs are unable to force out all air during expiration - reduces concentration gradient and therefore rate of diffusion
- as a result lungs ability to supply blood with oxygen progressively decreased
- lack of oxygen to muscles of body reduces respiration and energy available
Why do emphysema patients experience shortness of breath?
- difficulty in exhaling air due to loss of elasticity in lungs - if lungs cannot be fully emptied it is difficult to inhale fresh air so patient feels breathless
- smaller alveolar surface area leads to reduced levels of oxygen in blood so patient tries to increase oxygen supply by breathing more rapidly
- barrel-shaped chest - because of breaking down of the alveoli, air becomes trapped in the enlarged alveolar spaces and lungs become over-inflated
Why do emphysema patients experience a chronic cough?
consequence of lung damage and body’s effort to remove damaged tissue and mucus that cannot be removed because cilia on bronchioles has been destroyed
Why do emphysema patients experience a bluish skin colouration?
due to low levels of oxygen in blood as a result of poor gas diffusion in the lungs
How is a diagnosis of emphysema made?
- lung function tests
- chest X ray
- measurements of blood oxygen and CO2
- sputum examination
What will a lung X-ray show for someone with emphysema?
abnormally translucent lungs with few normal blood vessel markings
Can emphysema be cured?
no, because damaged lung tissue cannot be replaced
What are the forms of treatment for emphysema?
- stop smoking to prevent further damage
- antibiotic drugs to help control infection
- non-invasive positive-pressure ventilation = wearing nasal mask at night, supplied with air slightly higher than atmospheric pressure
- bronchodilators taken by inhaler
- steroids to reduce inflammatory swelling
- oxygen therapy
- alpha-1-antitrypsin enzyme replacement in those deficient of it
- exercise to increase physical ability
- surgery to remove worst affected part of lungs
What does cardiovascular disease refer to?
disease of heart and circulatory system
What does coronary heart disease affect?
coronary arteries (which supply heart muscle with glucose and oxygen)
What are atheromas?
fatty deposits, particularly cholesterol and LDL’s under wall of an artery under endothelial lining
