Respiratory pathology Flashcards
(62 cards)
What does COPD stand for ?
Chronic obstructive pulmonary disease
What is the basic problem for people with COPD?
They struggle to get air out of there lungs.
What are the names of the two conditions which combine to produce COPD?
Chronic bronchitis and emphysema
What is the largest risk factor for COPD ?
Smoking
What are some other risk factors for COPD ?
Pollution Dust Older age Genetics Socioeconomics
What is Alpha-1 Antitrypsin deficiency?
An inherited condition which causes early onset COPD and COPD lower in the lung than normal
Why does maternal smoking effect the risk of COPD ?
If a mother or grandmother smoked in pregnancy then the babies lungs will be smaller which causes an increased risk of COPD
What is the prognosis of COPD?
it is incurable and irreversible
What is Alpha 1 Antiprotease deficiency ?
It is a genetic condition which causes emphysema without chronic bronchitis
What is chronic bronchitis ?
It is a cough which produces sputum most days for three consecutive months for two or more consecutive years.
What condition does chronic bronchitis sometimes look like ?
Chronic bronchial asthma
What does Chronic bronchitis do to the large airways ?
Causes hyperplasia in the mucous glands and goblet cells
Minor inflammation
Fibrosis
What does chronic bronchitis do to the small airways ?
It causes the appearance of goblet cells
Long standing inflammation.
Fibrosis
What happens to complicate chronic bronchitis ?
Infection occurs and the FEV1 falls
What is emphysema ?
An increase beyond the normal size in the size of the airspaces distal to the terminal bronchioles arising as a result of dilation or destruction of walls.
i.e. loss of alveolar surface area
What is an acinus ?
The region of the lung distal to the bronchioles
What are the names of the different types of emphysema
Centriacinar emphysema
Scar emphysema
Panacinar emphysema
Periacinar emphysema
What is centriacinar emphysema ?
Emphysema which starts with the bronchiolar dilation and then alveolar tissue is lost. it is found at the top of the lobes
What s scar emphysema ?
No clinical effect but is the formation of emphysema next to scars
What is panacinar emphysema ?
Infects all the alveoli in a whole area of lung
What is periacinar emphysema ?
Causes loss of tissue at the edge of the acini and if it leaks air into the pleura cavity then it causes an pneumothorax to develop
What % of smokers will develop emphysema ?
Less than 50%
How does emphysema develop ?
In our healthy lungs we have neutrophils and macrophages that help protect us. These cells however produce elastase (protease) enzymes which if lets to build up in cause tissue destruction and emphysema in the lung. Therefore we also have anti-elastase (anti-proteases) which prevent elastases from causing tissue destruction. Note that the lung is not very good at repairing itself.
If there is a alpha 1 antitrypsin deficiency then there is a lack of anti-elastases which cause a build up of elastases and therefore tissue destruction. Smocking causes an decrease in anti-elastases as well as knocking out any repair mechanisms that the lungs did have and increasing the immune cell action which in tern produces more elastase. All of which result in an increase in tissue destruction.
Describe what happens to blood vessels when emphysema develops.
In Emphysemic lungs there is a reduced ability to perform effective gas exchange. This causes vasoconstriction of the blood vessels diverting blood to a better functioning alveoli. If the damage in the lungs is great this extensive construction in the lungs increases the pressure at which the heart must pump the blood to get it through the lungs therefore resulting in high blood pressure. It also causes cor pulmonale which causes hypertrophy of the right ventricle and can cause oedema. Long term vasoconstriction causes fibrosis which constricts vessels even further, loss of capillary’s which adds to the hypoxic state of the body, and production of red blood cells which makes the blood more viscous and harder to pump (known as secondary polycythaemia).
