Respiratory Pathology lecture 3

Question 1

Bronchioles do not contain ___ and ___ cells

Answer 1

Cartilage or goblet cells

Question 2

What cell is specific to bronchioles

Answer 2

Clara/ club cells

Question 3

What is the function of club/clara cells

Answer 3

1. Act as stem cells- divide to replace bronchiolar epithelium
2. Secrete protective factors- antimicrobial products, surfactant, oxidases (cytochrome P450)

Question 4

Why does innate susceptibility increase in the bronchioles

Answer 4

Fewer ciliated cells and no mucous layer so no mucociliary apparatus to help clear out inhaled particles

Question 5

Where is the site of gas exchange

Answer 5

Alveoli

Question 6

What type of cells are specific to alveoli

Answer 6

1. Type I pneumocytes
2. Type II pneumocytes

Question 7

What is the purpose of type I pneumocytes

Answer 7

Gas exchange- very thin

Question 8

what are the red and green arrows pointing at

Answer 8

Red: type II pneumocytes
Green: type I pneumocytes

Question 9

What are some functions of type II pneumocytes

Answer 9

Produce surfactant and act as stem cells to proliferate lost surface area when type I pneumocytes are damaged

Question 10

what does this image show? And why does this occur. How does it affect gas exchange

Answer 10

Type II pneumocyte hyperplasia due to non-specific response to alveolar injury

Decrease gas exchange because thicker

Question 11

What is the defense system of the alveoli

Answer 11

Alveolar and intravascular macrophages- phagocytosis

Question 12

What is the most vulnerable portion of the respiratory system

Answer 12

Alveoli

Question 13

What are the risk factors associated with RAO

Answer 13

Age, being stabled, possibly genetic

Question 14

What are the causes of RAO

Answer 14

Hypersensitivity response to inhaled particles- moldy hay, endotoxin

Question 15

What are some clinical signs of RAO

Answer 15

Exercise intolerance, flared nostrils, increased respiratory effort, heave line

Question 16

What is the heave line

Answer 16

Hypertrophy of abdominal muscles

Question 17

What are the gross changes associated with RAO

Answer 17

Hyperinflation- emphysema

Question 18

what are arrows pointing to and what is cause

Answer 18

Heave line- caused by RAO

Question 19

What occurs histologically with RAO

Answer 19

Goblet cell metaplasia—> mucus plug, smooth muscle hypertrophy, eosinophilia, peribronchiolar edema

Question 20

Why does a mucus plug form in RAO

Answer 20

Goblet cell metaplasia occurs and goblet cells not supposed to be in bronchioles which lack a mucociliary apparatus so can’t transport mucus out

Question 21

Horse in respiratory distress, flared nostrils, heave line. What is wrong

Answer 21

RAO- goblet cell metaplasia and mucus plug, smooth muscle hypertrophy

Question 22

What is cause of feline asthma

Answer 22

Hypersensitivity to inhaled allergens

Question 23

What is congestion and what does it typically indicated

Answer 23

Passive dilations of blood vessels

Typically indicates some degree of left sided heart failure

Question 24

What is hyperemia and what are some causes

Answer 24

Active dilation of blood vessels
Causes: acute inflammatory process, toxic, allergic, infection, aspiration pneumonia

Physiological- cold—> dilate BV

Question 25

What is hypostatic congestion

Answer 25

Blood congestion secondary to gravity, occurs postmortem

Question 26

What circulatory disturbance is present here

Answer 26

hyperemia or congestion

Question 27

what do these pictures indicate

Answer 27

Chronic left sided heart failure Hemosideran macrophages (HF cells) and hemosiderin gives lung brown appearance

Question 28

What are some causes of hemorrhage

Answer 28

1. Trauma 2. Coagulopathy 3. Ruptured vessels 4. EIPH

Question 29

what circulatory disturbance is present here

Answer 29

Hemorrhage

Question 30

What is the cause of EIPH

Answer 30

Massive rupture of small alveolar capillaries

Question 31

EIPH most commonly occurs in what horses

Answer 31

Race horses

Question 32

What is the major clinical sign of EIPH

Answer 32

Epistaxis

Question 33

What are some causes of pulmonary thromboembolism

Answer 33

1. Hepatic abscess 2. Endocarditis 3. Steroids 4. Loss of anti-thrombin III 5. IMHA 6. Heart worm 7. Neoplasia

Question 34

What is emphysema

Answer 34

Hyperinflation of alveoli potentially leading to septal rupture and fusion of airspace’s

Question 35

What is a bullae

Answer 35

Large air pockets caused by obstruction and increased alveolar pressures and/or alveolar septal weakness Secondary to emphysema

Question 36

What is wrong

Answer 36

emphysema Right: bullae

Question 37

What is atelectasis

Answer 37

Deflation/collapse of alveoli leading to partial or complete loss of air in alveolar spaces

Question 38

What is the gross appearance of atelectasis

Answer 38

Red, heavy firm, small, collapsed

Question 39

What pulmonary inflation disturbance would calf diphtheria cause

Answer 39

Atelectasis- mass occluding larynx

Question 40

What type of pulmonary inflammation disturbance would pleural effusion cause

Answer 40

Atelectasis

Question 41

what is wrong

Answer 41

Atelectasis