Pulmonary defense mechanisms + non-resp. functions of lungs

Question 1

What are the 6 primary defense mechanisms of the upper airways and bronchi?

Answer 1

1. –Anatomic barriers
2. –Cough
3. –Mucociliary apparatus
4. –Airway epithelium
5. –Secretory IgA
6. –Dendritic cells, lymphocytes, neutrophils

Question 2

What are the 4 primary host defense mechanisms of the alveolar spaces?

Answer 2

1. –Alveolar macrophages
2. –Immunoglobulins, opsonins, and surfactants
3. –Lymphocyte-mediated immunity
4. –Neutrophils and eosinophils

Question 3

Why is it important that defenses of the lung limit inflammation?

Answer 3

Causes probrems with gas exchange

Question 4

What immune cells are present in the lung airways?

Answer 4

Alveolar macros

resp. dendritic cells

virus specific B cells

Memory T cell

Question 5

What immune cells are found in the lung parenchyma?

Answer 5

Memory T cell

Resp. Dedritic cells

Question 6

Immune cells in lung draining lymph node?

Answer 6

Memory T cells

Lymph node dendritic cells

naive T cell

Virus specific B cell

Question 7

•A cough can be triggered by chemicals, mechanical stimulation, inflammation, or be voluntary. Describe the sequence of events in the cough reflex

Answer 7

1. Deep inspiration
2. Trapping of air by shutting off its exit (glottis in the case of cough)
3. Initiation of expiratory effort, raising the intrathoracic pressure
4. Build up of pressure
5. Sudden release of the trapped air at a high pressure

Question 8

Airway epithelium has is own complement of defensive mechanisms. Describe them

Answer 8

•Barrier function
•Defense function
–Release of bacteriostatic molecules
–Regulation of the immune response- contain receptors and

produce cytokines
•transport the IgA secreted by plasma cells

Question 9

What do the bacteriostatic molecules released by airway epithelium do?

Answer 9

Prevent bacterial growth

Question 10

BALT stands for?

Answer 10

Bronchial associated lymphoid tissue

Question 11

What defense molecules are contained in mucus?

Answer 11

•IgA, lysozyme, lactoferrin and peroxidases

Question 12

What particle size range does mucus deal with?

Answer 12

•Particles larger than 2-3 µm and smaller than 10 µm are deposited on the mucus of the upper airways

Question 13

What are three examples of disease states that alter the mucociliary clearance response?

Answer 13

Asthma

Chronic bronchitis

cystic fibrosis

Question 14

Mucins can be either…

Answer 14

secreted or attached

Question 15

What does CF arise from?

Answer 15

•CF arises from a mutation in the gene cystic fibrosis transmembrane conductance regulator (CFTR)

Question 16

What does loss of the transmembrane conductance regulator lead to?

Answer 16

•Loss of the protein prevents chloride transport out of the cell- results in Cl- and Na+ abnormalities

cystic fibrosis

Question 17

What is the end effect of CF?

Answer 17

• End effect is accumulation of a thick and viscous mucus
• In the lungs increased risk of infection is the outcome

Question 18

What type of disease state is cystic fibrosis?

Answer 18

obstructive

Question 19

What are some common pathogens that take advantage of CF patients?

Answer 19

•Pseudomonas aeruginosa, Burkholderia cepacia, Staphylococcus aureus, and Haemophilus influenza

Question 20

•How do mutations in the CFTR gene lead to susceptibility to respiratory infections with these pathogens?

Answer 20

These patients have diminished clearance of airways due to the thickened mucus.

Question 21

What immunoglobulins are found in the alveolar space?

Answer 21

IgA and IgG

Question 22

What non-immune opsins are found in the alveolar space?

Answer 22

–surfactant, fibronectin, and C-reactive protein

Question 23

Will you find neutrophils and eosinophils in the alveolar space

Answer 23

sure.

Question 24

What are the levels of immune defense in the respiratory system?

Answer 24

•Direct removal
•Chemical inactivation
•Protease/antiprotease
–Neutrophil elastase and metalloproteinases
–α1-antitrypsin
•Immune cell activation

Question 25

How are pathogens recognized by epithelial cells?

Answer 25

Ligation of toll-like receptors

Question 26

What does pneumonia refer to?

Answer 26

•Pneumonia refers to the condition of lung inflammation associated with alveoli filling in response to a lung infection

Question 27

What are predisposing factors of pneumonia?

Answer 27

–Age
–Immune status
–Presence of lung diseases

Question 28

In a patient with pneumonia, what happens to pulmonary blood flow?

ABG will change how?

If chest movement is restricted, what happens?

Answer 28

Altered by hypoxic vasoconstriction

Decreases in O2, CO2 drops or remains same

Chest wall restriction = pain, PFT may be more restricted but are of no use in patients with pneumonia.