Bronchial Asthma and COPD Nursing Notes , pathology
Chronic obstructive pulmonary disease (COPD)
- There are four types chronic obstructive pulmonary disease.
- 1-Emphysema
- 2-Bronchiectasis
- 3-Chronic bronchitis
- 4-Bronchial asthma
What is Bronchial asthma❔
Bronchial asthma is a condition where due to allergy airway becomes narrow and making breathing difficulties.
CLINICAL FEATURES OF BRONCpHIAL ASTHMA
1-Cough –in bronchial asthma due to any condition like dust , pollen , first inhale by a person if same person any allergic condition for this then airway becomes irritated swollen and filled with mucus .This irritution stimulates cough receptor so the body produces cough as a protective reflex .
2-Shortness of breath -In asthma airway become narrow due to inflammation so breathing difficulties occur .
3-Chest wheeze– In Asthma airway becomes narrow ,so air has to pass through tight space so whistling sound come out during respiration .
ETIOLOGY
1-Pollen
2-Air pollutants
3-Noxious chemical
4-Viral infection of the upper respiratory tract
5-Stress
6-Exercise
PATHOGENESIS OF BRONCHIAL ASTHMA
During first contact the antigen enter inside the body through airway.
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Antigen is captured by antigen presenting cell ( APC eats and breaks the antigen into small fragments .APC keep that antigen on its outer surface.
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Th2 cell recognise the antigen and get activated.
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TH2 cell releases interleukin 3, interleukin 4, Interleukin 5( cytokines)
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Interleukins 4 causes activation of B cell ( Activate B lymphocytes)
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Activated B lymphocytes transform plasma cell that produce IgE antibody .
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IGE antibody production
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IgE antibody Bind to the FC receptor present on the mast cell
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Mast cell fully sensitized for next event ( After binding mast cell ready to react with same antigen in next event.)
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During the second contact with same antigen
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Antigen bind with IGE antibody on the surface of the mast cell activated.
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Mast cell Lysis
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Degranulation of mast cells ( mast cell contain leukotrienes which came out by mast cell break down)
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Leukotrienes ( Leukotrienes receptor are present in trachia and bronchial wall so these leuKotrienes attached with their receptor causes bronchospasm.
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Bronchospasm
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Asthma
TYPES OF ASTHMA ( Two broad types of asthma)
1-Extrinsic asthma or atopic Asthma
Extrinsic asthma or atopic asthma is a condition which occurs due to allergic reactions. Such as ,dust and pollens
Sensitization phase -Sensitization phase means body becomes ready or sensitized so that next time when Antigen enters the body strong asthma attack happens (Because our body here try to protect from allergens such as dust and dirt )
When allergen enters the body such as dust ,pollen and smoke .
Our immune system get activated
Th2 type of lymphocyte get activate and release chemicals interleukin-4 , Interleukin -5 .
These chemicals tells B cell to make antibodies.
B- cell produced IgE antibodies
IgE attach mast cell in the lungs
Re -exposure phase –
Allergen enters again
It binds IgE attach which is already present on mast cell
Then mast cell break open ( degranulation)
These mast cell releases its stored chemicals histamine into surrounding tissues.
When mast cell release histamine smooth muscle of airway contract and this is called
2-INTRINSIC OR NON ATOPIC ASTHMA
Intrinsic or non atopic asthma is a type of bronchial asthma is not caused by allergic reactions or not family history of allergic reactions.
In nonatopic asthma IgE is normal so it is not allergy.then why asthma happens
When a person inhale dust or pollen etc , then dust and pollens enter to airway then vagal receptor ( Nerve ending).
and vagus nerve get stimulated and airway muscle contract.Bronchospasm occur .
Drug induced asthma
Drug induced asthma is a condition which occurs due to certain medicine,
COMPLICATION OF ASTHMA
1-Emphysema ( is a lung disease in which alveoli becomes enlarged and damaged .
2-Recurrent infection -Frequent chest infection due to excess Accumulation of mucus and blocked airway.
GROSS APPEARANCE ( means you can see in naked eye)
1 -Narrowed lumen of the airway
2-Increased weight and size of the lungs
2-Atelectasis (/Lung collapse)
4-The walls of the bronchi are thickened and are filled with mucus plugs .
HISTOLOGICAL CHANGES
1-Smooth muscle cell hyperplasia
( due to bronchoconstriction and inflammation In the walls of airway smooth muscle cells number increase/)
2-Bronchial gland hyperplasia (Increase number of mucus secreting glands in walls of airway )
3-Submucosal edema (fluid accumulate in the submucosal
4-Inflammation including eosinophils ( A type of white blood cell Eosinophils you can see under microscope)
5-Mucous plugs and mucous gland hyperplasia ( Due to mucous gland hyperplasia, mucous secrete more than normal and form mucus plugs and obstruct airway.
6-Increased vascularity -Due to inflammatory reaction increased blood flow )
7- The presence of charcot -Leyden crystals– If asthma due to allergic condition then Immediately a type of white blood cell eosinophils run that site to fight.and after fighting some eosinophils died and breakdown down and release protein
one of these proteins form charcot -Leyden crystals- which we can see by microscope.
Charcot-Leyden_crystal_-_Asthma.jpg
8-Curschmann spirals – Due to inflammation in airway mucus secretion increases and collect in bronchi and bronchioles,when patient cough ,this sputum expelled out with form of spiral shape is called curschmann spirals.we can seen in sputum of the bronchial asthma patients in microscope.
9-Creola bodies – In bronchial asthma due to inflammation damage epithelial lining .and epithelial cells looses and detach from wall of airway and come out in sputum as a cluster called creola bodies.
