Pathology of Respiratory System

Question 1

What is the epithelia of the respiratory system?

Answer 1

ciliated epithelium; more prone to being damage than other epithelium due to its specific structs

Question 2

What shape are Type I pneumocytes?

Answer 2

Flat & thin for gas exchange

Question 3

What shape are Type II pneumocytes?

Answer 3

cuboidal -> source of new Type I pneumocytes; lost Type I pneumocytes will be replaced by Type II

Question 4

What is a pluck?

Answer 4

Tongue, larynx, esophagus, trachea, heart, & lungs

Question 5

What kind of artifacts are seen in the lungs?

Answer 5

• many & common
• colour change is often misleading
• palpation is crucial (lungs more firm that usual)

Question 6

Why does respiratory disease increase in food animals around Nov?

Answer 6

colder, animals brought inside, transported, mixed w/ other animals

Question 7

Why may a lung be dark in colour?

Answer 7

Potentially due to congestion; potentially animal was laying on its side & blood pooled post death

Question 8

Why might there be white lines on the stomach?

Answer 8

could be rib impressions or expansion of stomach from gas

Question 9

What happens when you euthanize with intracardiac euthanol?

Answer 9

It will precipitate out & sit on the lungs; this is artifact of euth w/ no sig outside of this; this dissolves away if put in solution

Question 10

Thickened dorso-caudal pleura on lungs means?

Answer 10

this is probably normal genetic variation (seen in cattle)

Question 11

Two lungs of diff size, one dark in colour, one pale pinkish

Answer 11

Probably just congestion in darker one; pale pink one should be light while dark, fluid filled one should be heavy (“wet”)

Question 12

What is hyperemia in the cranio-ventral portion of the lung?

Answer 12

SIGNIFICANT

Question 13

What are the 4 causes of edema?

Answer 13

1. Increased hydrostatic pressure
2. Reduced oncotic pressure
3. Endothelial damage
4. Lymphatic obstruction

Question 14

Signs of pulmonary edema?

Answer 14

Foam filled trachea (a little bit near where the bronchi come off is normal) or widened interlobular septa

Question 15

Signs of hemorrhage in lung?

Answer 15

Hard to see because they are just areas of redness; need to feel them (areas of hemorrhage will feel firmer)

Question 16

How common are pulmonary embolisms?

Answer 16

Lungs are a common place to see embolisms b/c a clot travelling down venous side will go through progressively larger areas until it hits the lungs where it gets small; not seen that frequently in veterinary spp

Question 17

Significance of pulmonary/pleural ossification

Answer 17

seen particularly in older animals and particularly in dogs. No clinical significance. Just bone fragments on surface of lung.

Question 18

What is anthracosis?

Answer 18

Black discoloration of bronchial mucosa that can occlude the bronchial lumen (it is just dust contained w/in macrophages

Question 19

Big black spots on lungs?

Answer 19

big black spots could be melanosis, melanoma, or v dark hemorrhage. should palpate them to make sure it’s not just a colour change. Melanoma would feel like a mass; unlikely to be inhaled pollution or carbon (pattern would be more diffuse)

Question 20

What is atelectasis?

Answer 20

When air exits alveoli & they collapse, lung goes from pale pink poofy to darker deeper red (colour is more concentrated from collapse (darker); probably a little firmer)
- ex: when lung is blocked w/ mucus
- atelectasis can be pathological (relating to disease) or not

Question 21

What do goblet cells do in the lungs & what problems can it lead to?

Answer 21

Goblet cells make mucus and a large amount of mucus can build up and block airways

Question 22

What is emphysema?

Answer 22

alveolar septa no longer exist so have larger bubbles w/in lung , so less SA for gas exchange

Question 23

What are the two types of emphysema?

Answer 23

1. Alveolar -> areas of the alveoli are expanded w/ air
2. Bullous -> larger areas of lung are expanded w/ air

Question 24

How does smoke lead to emphysema?

Answer 24

Smoke induced frustrated phagocytosis -> release of elastase -> elastase destroys elastin -> leading to smoke induced pulmonary emphysema

Question 25

Significance of combination of atelectasis & alveolar emphysema?

Answer 25

Atelectasis will be that darker part of the lung & the bright red stuff is emphysema; seen commonly in euth’d animals (not significant, feels like snap, crackle, pop)
- he thinks animals hyperinflate their lungs when they take a big agonal gasp upon euth