Defense Mechanisms of the Respiratory Tract

Question 1

Defense mechanisms of the conduction system (4)

Answer 1

1. Mucociliary clearance
2. Antibodies
3. Lysozyme
4. Mucus

Question 2

Defense mechanism of the air exchange system (4)

Answer 2

1. Macrophages
2. Surfactant
3. Antioxidants
4. Antibodies

Question 3

How can the defense mechanisms be impaired? (5)

Answer 3

1. Viral infections
2. Bacterial infections
3. Toxic gases
4. Immunodeficiency
5. Other health ailments

Question 4

What is a Clara cell and what role does it play in the respiratory tract?

Answer 4

part of the epithelium of bronchioles
secrete surfactant
stem cells to replace non-ciliated/ciliated cells

Question 5

What leukocyte is most important for protection of the alveolus and at what anatomic site in the alveolus is this leukocyte located?

Answer 5

macrophages, located in alveolar wall near interstitium

Question 6

Compare and contrast type I and type II pneumocytes in terms of structure and function

Answer 6

Type 1 Pneumocyte

• membranous, thin
• O2 diffusion

Type 2 Pneumocyte

• cuboidal with microvilli
• secrete surfactant
• stem cells to replace Type 1 pneumocytes

Question 7

What is the location and function of M cells in the lung?

Answer 7

located in bronchi

• overlie BALT
• deliver antigen to macrophages
• stimulate humoral and cell-mediate immunity
• produce sIgA

Question 8

How do M cells contribute to the immune response?

Answer 8

• deliver antigen to macrophages

- stimulate humoral and cell-mediated immunity

Question 9

What antibody is most important in M cells?

Answer 9

sIgA