Pulmonary Pathology 1 Flashcards
(43 cards)
True or False: Any alveolar filling process (pneumonia, alveolar hemorrhage, etc) causes restrictive pattern because it dilutes surfactant and fill alveoli which reduce the compliance of the lung.
True.
What does mucus do in the airways?
Protects the lungs from the things that you’re inhaling. It makes the walls of the airways really sticky so particulates, bacteria, etc. get stuck in the mucus and can be moved up and out of the airway by the epithelium.
In the bronchi, the epithelium is ciliated ____
columnar
True or False: As you get into smaller airways, there are less ciliated epithelial cells.
True. As you get into smaller airways, the air is more or less already sterile.
What is acute bronchitis typically caused by and how is it characterized?
Acute bronchitis is typically caused by bacterial infections that come on quickly and is characterized by neutrophils in the airway lumen and infiltrating wall.
What’s going on here?
This is acute bronchitis. You can see that the airway is occluded by mucus and neutrophils (fragmented/multi-lobar nuclei). Neutrophils are typically responding to bacterial antigens.
When you see acute inflammation in the airways, think acute bronchitis.
What is chronic bronchitis and how is it characterized?
Chronic bronchitis is characterized by chronic inflammation. The inflammation can be caused by many different things (e.g. chronic infections, autoimmune diseases, etc). With chronic inflammation, you have lymphocytes instead of neutrophils.
When you see neutrophils in airways, think of acute bronchitis. When you see lymphocytes, think chronic bronchitis.
Over time, the airway epithelium undergoes squamous metaplasia (much tougher–to try to protect against chronic injury) and you have mucus gland hypertrophy (secreting more mucus to try to protect against chronic injury)
What’s going on here?
Chronic bronchitis.
You can tell that it’s chronic inflammation because the cells there are lymphocytes, not neutrophils. Neutrophils have multi-lobed nuclei and cytoplasm while the lymphocytes are blue without cytoplasm.
What happens to the epithelial layer in chronic bronchitis?
Squamous metaplasia (a reaction to protect against the chronic inflammation)
The cells start to turn into squamous cells that are tougher and more protective. It starts to look a lot like outside skin.
It is thought that squamous metaplasia is an early step leading to cancer.
What happens to mucus glands in chronic bronchitis?
Mucus gland hyperplasia.
There is proliferation of the mucus glands and you get increased secretion of mucus to try to defend the airways against chronic insults.
What is bronchiectasis and how is it characterized?
Bronchiectasis happens when you have things like chronic bronchitis and recurrent infections year after year and is characterized by airway dilation.
It’s often seen in cystic fibrosis as cystic fibrosis patients are more prone to infection.
You can also see this in patients that get infected with tuberculosis (because these infections can last a very long time). When airways are inflammed and injured for a long time, they can become dilated.
In bronchiectasis, as airways get ____, the body has a harder time controlling ______. This can lead to ____.
bigger (dilated), what’s inside of the airways, infection
As the airways get too big, things in the airway become far away from the blood supply so the immune response can’t reach them to control them.
What’s the easiest way to see if there is bronchiectasis?
Compare the airway to its corresponding artery (they almost always run together). They should have lumens about the same size. If the airway is bigger, there is bronchiectasis.
With acute bronchitis, you have neutrophils. With chronic bronchitis, you have lymphocytes. What about for asthma? What WBC do you have?
Eosinophils
What are 4 pathology characteristics of asthma?
- Thickened subbasal lamina
- Eosinophilic inflammation (the eosinophils all go away if treated with steroids, so eosinophils may not be present in a biopsy of a treated patient)
- Mucus hypersecretion
- Smooth muscle hyperplasia (gets bigger bc it’s getting exercised throughout episodes)
What’s going on here?
Asthma. Asthma histology has a pink band-like area under the epithelium that is thickened (subbasal lamina).
What’s going on here?
Allergic asthma (eosinophils present).
They have red cytoplasm and have bi-lobed nuclei
What’s going on here?
This is asthma. You can see the thickened subbasal lamina under the epithelium. There is mucus hypersecretion in asthma in response to the inflammation in the airway.
What’s going on here?
Asthma. You can see the thickened subbasal lamina under the epithelium. Also, you can see smooth muscle hyperplasia. Typically, the smooth mucle is supposed to be the same thickness as the epithelial layer but it is about 8 times thicker in this picture. This shows that the smooth muscles have been built up (exercised by the asthma episodes).
True or False: You can diagnose asthma with positive histology findings
False. You have to diagnose asthma clinically (reversible bronchoconstriction).
Asthma patients typically aren’t biopsied anyways. We just happen to have these biopsies incidentally.
What is chronic bronchiolitis?
Like chronic bronchitis, chronic bronchiolitis is chronic inflammation in the wall of bronchioles with the presence of lymphocytes in the bronchiole walls.
What’s going on here?
(Cellular) Chronic Bronchiolitis
There are lymphocytes infiltrating the wall of the bronchiole (causing squeezing of the airway) which is a sign of chronic bronchiolitis. This is potentially reversible if you can get rid of the inflammation.
What is follicular bronchiolitis?
Follicular bronchiolitis is a kind of chronic bronchiolitis that forms germinal centers of lymphoid aggregates next to the bronchioles. You have B-cells in the center surrounded by T-cells at the edge. It takes germinal centers a long time to form so this suggests bronchiolitis that has been present for a long time.
What is constrictive and obliterative bronchiolitis?
This is when inflammation of the bronchioles causes fibrosis and scarring which causes the bronchioles to close. Fibrisis/scarring is irreversible. Airways beyond scarring are essentially non-functional.
In the picture, you can see the inflammation present with the WBCs, and under the arrow, the pink stuff is fibroblasts starting to squeeze the airway shut. If you look at the smooth muscle above the arrow, you can see that it is far away from the airway epithelium. That’s because the fibrosis grew in between. Below the airway, you can see the typical distance expected between smooth muscle and airway epithelium.
