ASTHMA Flashcards
WHAT IS ASTHMA and what happens to the lungs
Asthma is a chronic respiratory disease that involves the narrowing and swelling of the airways, leading to difficulty in breathing. The main feature of asthma is recurrent attacks of bronchospasm. The bronchi become inflamed, and the muscles around them tighten. At the same time, the lining of the airways produces excess mucus, further narrowing the airways and making it harder for air to pass through. This results in symptoms like wheezing, coughing, and shortness of breath
What is bronchospasm
a sudden constriction of the muscles in the walls of the bronchi, the air passages that lead from the trachea to the lungs.
what tiggers bronchospasms
These bronchospasms are often triggered by allergic reactions, such as exposure to pollen, pet dander, or dust mites. In other cases, asthma can be triggered by environmental factors, such as cold air, exercise, or irritants like smoke. Asthma can also have a hypersensitivity component, where the immune system overreacts to harmless substances.
what is the role of smooth muscles in the bronchioles and what happens to them during asthma?
Smooth muscles contract and relax, controlling the diameter of the airways. in conditions like asthma, these smooth muscles can become hyperreactive and constrict, leading to airway narrowing and difficulty in breathing
what are the two main causative factors to trigger asthma
Intrinsic and extrinsic
what is intrinsic asthma and what causes it?
Intrinsic asthma differs from allergic (extrinsic) asthma in that it is not triggered by allergens, and it is more likely to occur in individuals who have long-standing respiratory conditions such as chronic bronchitis or infections. In intrinsic asthma, various stimuli cause the airways to become hyper-responsive, leading to bronchoconstriction and inflammation.
-infection
exposure to cold
-drugs[such as aspirin]
-stress
-inhalation of irritants
what is bronchoconstriction
it is the tightening of the smooth muscles surrounding the airways, leading to narrowed air passages
what is inflammation
its when swelling and increased mucus production in the airways, which further obstructs airflow
what are symptoms of asthma?
-wheezing
-shortness of breath
-coughing
-chest tightness
what is the management of asthma?
-bronchodilators[salbutamol, ipratropium bromide, Hydrocortisone
-Inhaled corticosteroids
-Avoidance of triggers
what is Extrinsic Asthma?
(also known as allergic asthma) is the most common form of asthma, typically triggered by an allergic reaction to external allergens. . In extrinsic asthma, exposure to specific allergens triggers an exaggerated immune response, resulting in airway inflammation, bronchoconstriction, and increased mucus production.
What triggers extrinsic asthma
-pollen
-dust mites
-mold spores
-food allergies
-pet dander
-food allergies
what is IGE and how does it help against asthma?
IGE is an antibody that is produced by the immune system and it helps fight infection. IGE is triggered in people with asthma when they get exposed to pollen dust mites or pet dander. example]
First exposure (Sensitisation): when you get exposed to pollen your immune system mistakenly thinks it’s harmful.
Your body produces IgE antibodies, which then attach to special cells in your body called mast cells. These cells are now “armed” and ready for future exposure.
Re-exposure (Allergic Reaction):
The next time your exposed to pollen, the IgE antibodies on your mast cells recognise the pollen as an allergen.
This causes the mast cells to release chemicals like histamine, which leads to the following:
Tightening of airways (bronchoconstriction): The muscles around your airways squeeze, making it harder to breathe.
Mucus production: Your airways produce extra mucus, clogging the passages.
Swelling (inflammation): The walls of your airways become swollen, narrowing the space for air to pass through.
what is the immune response to asthma
-histamine is released which causes the blood vessels to become leaky leading to swelling[oedema]
-kinins are also released these are chemicals that cause blood vessels to vasodilate and muscles around the airway to bronchoconstrict
-prostaglandins also causes blood vessels to vasconstrict which can lower blood pressure and reduce blood flow to the lungs, mucus is produced by goblet cells in the airways.
-Leukotrienes-white blood cells
what happens to the vagus nerve during asthma attack?
It over stimulates through excessive coughing causing a reflex bronchoconstriction and bronchospasm.Because of this, air gets trapped in the lungs, making it hard to breathe out properly. When someone tries to forcefully exhale, it can lead to the collapse of the bronchi (the airways).
As a result, the amount of air left in the lungs (residual volume) increases, which makes coughing less effective and prevents mucus from being cleared. In severe cases, it can lead to irregular heartbeats (arrhythmias) and depression of the central nervous system (CNS).
