Exam 2: Respiratory Pathology

Question 1

Which nerve is there damage to in laryngeal hemiplegia?

Answer 1

Damage to the left recurrent laryngeal nerve supplying the dorsal cricoarytenoid muscle. usually idiopathic.

Question 2

What are malignant epithelial cells, glands, blood vessels, nerves, cartilage, bone, lymph nodes… called?

Answer 2

carcinoma
adenocarcinoma
hemangiosarcoma
esthesioneuroblastoma
chondrosarcoma
osteosarcoma
lymphoma

Question 3

What cells do terminal bronchioles have and what do they contain?

Answer 3

Terminal bronchioles have non-ciliated Clara cells which contain cytochrome P450 and other enzymes that can metabolize toxins.

Question 4

Which cells in the basement membrane make mucous?

Answer 4

goblet cells

Question 5

What is surfactant made of, its functions and the job of Type A+D?

Answer 5

Surfactant
Mostly phosphatidylcholine
Prevents alveolar collapse
Removes debris to the mucociliary system
Types A+D can opsonize pathogens and activate macrophages

Question 6

What are pores of Kohn and which species do not have them?

Answer 6

Dog cat horse people=pores of Kohn. Cow/pig: no pores

connect adjacent alveloli and adjacent lobules.
when you have infection in one litttle area, can readily spread to other areas.
cows and pigs do not have this connection, can have pink aerated healthy lobules next ot dark congested diseased lobules.
pneumonia in cattle and pigs more patchy.

Question 7

What are the six layers of the blood-air barrier?

Answer 7

Blood-air barrier is 6 layers thick:
Surfactant layer
Type 1 pneumocyte
Basement membrane
Loose connective tissue
Basement membrane
Endothelial cell

Question 8

Where is lung lobe torsion more frequent?

Answer 8

Most frequent in right middle lobe of deep chested dogs and cats, left cranial lobe in small dogs. Twisted at hilus, congested

Question 9

A farmer has a dead baby animal. He wants to know if there was fowl play or if they were stillborn. You necropsy the fetus. What would you find if the animal never took their first breath?

Answer 9

fetal atalectasis. You can check by seeing if the lung will float (evidence there is air in the lungs)
post-mortem bacteria can produce gas and cause false floating.

Question 10

What are some nonspecific respiratory defense mechanisms?

Answer 10

• Mucociliary apparatus
• Alveolar macrophages, intravascular macrophages
• Antimicrobial peptides
• Cough and sneeze reflexes
• Alveolar clearance by inactivation or mechanical clearance

Question 11

What are the three main types of emphysema and how do they present?

Answer 11

Alveolar
* Permanent enlargement of alveoli due to destruction of the alveolar septa
* pale, puffy lungs, may see small vesicles or bullae formed by coalescence of alveoli
* Histo: destruction of walls and enlarged spaces
Overinflation is caused by overexertion in inspiration.
* In animals it is usually agonal gasping
* Lysis of elastin is central. Possibly caused by elastases in PMN’s or macrophages, which respond in situations of chronic irritation

Interstitial
* Air is present in connective tissues, interlobular septa
* Due to a number of causes:
1. Positive pressure ventilation
2. Incidental finding in cows at slaughter
3. Recumbent cows (“downers”)
Cows forceably exhale against a closed glottis

• Cows with respiratory distress due to 3-methyindole toxicity, other toxins, or pneumonia due to bovine respiratory syncytial virus
• In forced expiration air passes through intact alveolar septa to the connective tissues

Question 12

A horse has clinical signs that include difficult respiration and is having difficulty coughin up mucous so has developed a “heave line” this is pathognomonic for what pulmoary disease?

Answer 12

Chronic bronchiolitis (oka, COPD or RAO)

Question 13

cattle are all on a feedlot, their defenses are impaired and there is a bunch of airborne virulents you can see with your magic eye. What are you weary of?

Answer 13

bronchopneumonia

Question 14

You are at a necropsy table and a terrible looking lung comes out of a carcass. You don’t know the history yet but you see he lungs are discolored and firm in a cranio-ventral distribution. What kind of pneumonia are you thinking? are you thinking inhaled or bloodborne?

Answer 14

bronchopneumonia, inhaled

Question 15

What is the difference between atalactesis and bronchiectasis and what is the mechanism for why they present the way they do?

Answer 15

Atelectasis, the collapse of part or all of a lung, is caused by a blockage of the air passages (bronchus or bronchioles) or by pressure on the lung.

Bronchiectasis is a chronic condition where the walls of the bronchi are thickened from inflammation and infection.

Question 16

What are the parts of the respiratory system and their function?

What is the function of the nasal passage, clara cells, and mucous and where are they located?

nasal to terminal bronchioles

Answer 16

The nasal passage will trap particles bigger than 10 microns in the pharynx.

Terminal bronchioles have non-ciliated clara cells that contain cytochrom P450 and other enzymes that can break down toxins.

Mucous is down in the bronchioles as well as the ciliary excalator that can help cough up pathogens, additionally, mucous dissolves inhaled gasses keeping them from the alveoli where they can damage type 1 pnuemocytes. IgA is also found here.

Question 17

What are the parts of the respiratory system and their function?

What is in the alveolus? What cells are in there and what do they do?

Answer 17

surfactant, it prevents alveolar collapse and removes debris to the mucilary system. types Aand D can opsonize pathogens and activate macrophages.

Type II pneumocytes create sufactant and have microvilli. Type I stems from Type II and opt to become 1 when they see Type II fail.

Question 18

wehich species do and dont have pores of kohn?

Answer 18

dog, cat, horse and people do.

cows and pigs dont.

Question 19

Some common viral and fungal nasal diseases that can digest tissues and be very destructive? What about the larynx?

viral, bacterial, fungal, parasitic, and atrophic rhinitis

Answer 19

viral rhinitis: infectious bovine rhinotracheitis in cattle (can also affect larynx), feline rhinotracheitis (herpes 1), feline calcivirus

bacterial rhinitis: rare, Glanders-Burkholderia mallei.

fungal rhinitis: Aspergillus fumigatus, Cryptococcus neoformans (dogs and cats) - german sheperds love to get this.

parasitic rhinitis: Oestrus ovis (sheep), Linguatula serrata in dogs

atrophic rhinitis: P. multocida

Laryngeal: F. necrophorum to damaged epithelial tissue, laryngeal hemiplegia damage of left recurrent laryngeal nerve which causes protrusion of laryngeal saccules and causes roaring sound in horses,

Question 20

There are two scenarios where you cna have incomplete expansion of the lung, what is the term for this and what are the two scenarios?

Answer 20

atalectasis, can be fetal when lungs neverexpans or compressive due to hydrothorax, a hernia… etc.

Question 21

What are the three types of emphysema? when can you confuse overinflation?

Answer 21

alveolar is permanent enlargement of the alveoli where there is destruction of the alveolar septa. overinflation can be due to overexertion in inspiration where there may have been lysis of elastin from alastases.

interstitial emphysema is when air is present in the connective tissues or interlobular septa. This can be an incidental finding in cows at slaughetr, due to a positive pressure ventilation, or downer cows. can also happen in cows due to respiratory distress like 3-methyindole toxicity.

chronic bronchiolitis emphysema in horses is due to recurrent airway obstructions (RAO) and is commonly referred to as the “heaves”. horses often develop a “heave” line and grossly in addtion to emphysema, you will see mucoid exudate in the bronchioles and bronchi.