01 - Resp Antmy & Histo - dfns mchnsms

Question 1

(Define the Air Conduction system of the respiratory tract)

1. what comprises it?
2. What is the transitional system?
3. What is the gas exchange system?

Answer 1

1. nasal, paranasal, trachea, bronchi
2. the bronchioles
3. the alveoli (alveolar ducts, alveolar sacs, and alveoli)

(should read pp 6-7 of guide on this stuff)

Question 2

2.1 What portions of the respiratory tract are lined by ciliated respiratory epithelium?

Answer 2

the conducting system

the transitional system (ciliated respiratory epithelium decreases from proximal to terminal bronchioles - becomes attenuated in secondary and tertiary)

gas exchange NOT lined

Question 3

2.2 What role does ciliated respiratory epithelium play in mucosal defense?

Answer 3

2.2 mucociliary apparatus - the cilia function to move the mucus upwards which has all the shit in it

might want to get more info on this one

Question 4

2.3 Where are mucous cells (secretory goblet cells) located?

Answer 4

2.3

Conducting system - variable portion of mucous cells

transitional system - decrease from proximal to terminal (goblet cells absent in terminal bronchioles)

Question 5

3. List several ways in which the avian respiratory system differs from the mammalian respiratory system

5 ways

Answer 5

1. choanal slit in upper palate communicates directly with nasal cavity
2. soft-walled infraorbital sinus located ventromedial to eye and communicates directly with nasal cavity
3. dorsal and ventral bronchi –> parabronchi –> air capillaries. Air diffuses from air capillaries into adjacent blood capillaries
4. Avascular air sacs serve as bellows (nine in most birds)
5. Two cycle respiration with unidirectional air movement and greater oxygen exchange via counter current mechanism (compared to mammal)

(look on page 9-10 for example of this)

Question 6

4. What is the most predominant antibody produced in the air conduction system (airway)?
5. How does this antibody function?

Answer 6

4. IgA
5. Ligation of FcαRI by IgA containing immune complexes causes antibody-dependent cell-mediated cytotoxicity (ADCC), degranulation of eosinophils and basophils, phagocytosis by monocytes, macrophages, and neutrophils, and triggering of respiratory burst activity by polymorphonuclear leukocytes

Question 7

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

Answer 7

1. present in bronchioles (transitional system)

secrete proteinaceous fluid (not mucus)

Serve as stem cells if bronchioles are injured. Replace non-ciliated and ciliated cells

Rich in smooth endoplasmic reticulum (cytochormoe P-450 enzymes) to metabolize endogenous and exogenous substances

Can create reactive metabolites from inhaled substances

Question 8

3. What leukocyte is most important for protection of the alveolus?
4. at what anatomic sites in the alveolus is this leukocyte located?

Answer 8

1. the macrophage
2. pulmonary intravascular macrophages reside in lung capillaries

alveolar, interstial, and intravascular

Question 9

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

(Type 1 Pneumocytes)

1. membranous (flattened) epithelium is very thin - covers over how much surface area?
2. gas exchange… give order of travel through membrane
3. susceptible to injury?
4. Can they divide?
5. metabolically active?

(Type 2 Pneumocytes)

1. shape?
2. metabolically active?
3. secrete what?

that does what?

4. serve as what?
5. type II pneumocytes can become hyperplastic (“epithelialization”) if type 1 pneumocytes are depleted… leads to what?

Answer 9

1. 95% alveolar area
2. oxygen –> alveoalr epithelium (mostly type 1) –> basement membrane –> intersitium –> basement membrane –> endothelium –> bloodstream
3. very
4. no (terminally differentiated)
5. no
6. cuboidal with microvilli (not cilia!)
7. yesss
8. surfactant (complex of phospholipids and proteins (A-D))

reduce surface tension

enhance phagocytosis by activating macrophages

4. stem cells to replace type 1
5. creates barrier to gas diffusion

Question 10

(5. What is the location and fuction of M cells in the Lung? How do they contribute to the immune response and what antibody is most important?)
1. What is the location?
2. function?
3. stimulate what type of immunity?
4. which antibody is most important?

Answer 10

1. in the conducting system (in the bronchi)
2. deliver antigens to macrophages and other “antigen presenting cells” (Which then transfer to B and T lymphocytes of BALT)

overlie bronchus-associated lymphoid tissue (BALT) phagocytose particulatres and soluble antigens

3. both humoral and cell-mediated
4. IgA

Question 11

1. 1. List defense mechanisms of the respiratory tract (conduction and air exchange systems) and examples of how those mechanisms can be impaired

look on page 13 for list

page 17 for what can go wrong