Pulmonary defense mechanisms + non-resp. functions of lungs Flashcards
What are the 6 primary defense mechanisms of the upper airways and bronchi?
- –Anatomic barriers
- –Cough
- –Mucociliary apparatus
- –Airway epithelium
- –Secretory IgA
- –Dendritic cells, lymphocytes, neutrophils
What are the 4 primary host defense mechanisms of the alveolar spaces?
- –Alveolar macrophages
- –Immunoglobulins, opsonins, and surfactants
- –Lymphocyte-mediated immunity
- –Neutrophils and eosinophils
Why is it important that defenses of the lung limit inflammation?
Causes probrems with gas exchange
What immune cells are present in the lung airways?
Alveolar macros
resp. dendritic cells
virus specific B cells
Memory T cell
What immune cells are found in the lung parenchyma?
Memory T cell
Resp. Dedritic cells
Immune cells in lung draining lymph node?
Memory T cells
Lymph node dendritic cells
naive T cell
Virus specific B cell
•A cough can be triggered by chemicals, mechanical stimulation, inflammation, or be voluntary. Describe the sequence of events in the cough reflex
- Deep inspiration
- Trapping of air by shutting off its exit (glottis in the case of cough)
- Initiation of expiratory effort, raising the intrathoracic pressure
- Build up of pressure
- Sudden release of the trapped air at a high pressure
Airway epithelium has is own complement of defensive mechanisms. Describe them
•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
What do the bacteriostatic molecules released by airway epithelium do?
Prevent bacterial growth
BALT stands for?
Bronchial associated lymphoid tissue
What defense molecules are contained in mucus?
•IgA, lysozyme, lactoferrin and peroxidases
What particle size range does mucus deal with?
•Particles larger than 2-3 µm and smaller than 10 µm are deposited on the mucus of the upper airways
What are three examples of disease states that alter the mucociliary clearance response?
Asthma
Chronic bronchitis
cystic fibrosis
Mucins can be either…
secreted or attached
What does CF arise from?
•CF arises from a mutation in the gene cystic fibrosis transmembrane conductance regulator (CFTR)
What does loss of the transmembrane conductance regulator lead to?
•Loss of the protein prevents chloride transport out of the cell- results in Cl- and Na+ abnormalities
cystic fibrosis
What is the end effect of CF?
- End effect is accumulation of a thick and viscous mucus
- In the lungs increased risk of infection is the outcome
What type of disease state is cystic fibrosis?
obstructive
What are some common pathogens that take advantage of CF patients?
•Pseudomonas aeruginosa, Burkholderia cepacia, Staphylococcus aureus, and Haemophilus influenza
•How do mutations in the CFTR gene lead to susceptibility to respiratory infections with these pathogens?
These patients have diminished clearance of airways due to the thickened mucus.
What immunoglobulins are found in the alveolar space?
IgA and IgG
What non-immune opsins are found in the alveolar space?
–surfactant, fibronectin, and C-reactive protein
Will you find neutrophils and eosinophils in the alveolar space
sure.
What are the levels of immune defense in the respiratory system?
•Direct removal
•Chemical inactivation
•Protease/antiprotease
–Neutrophil elastase and metalloproteinases
–α1-antitrypsin
•Immune cell activation
