Respirotoxicity

Question 1

What is the primary site of gas exchange in the body?

Answer 1

The lungs are the primary site of gas exchange, O2, and CO2.

Question 2

What type of epithelium is found in the upper tract of the respiratory system?

Answer 2

The upper tract of the respiratory system is pseudo-stratified in the nasal cavity, trachea, and bronchi.

Question 3

What are ciliated cells responsible for?

Answer 3

Ciliated cells have fine hairs that beat to expel debris into the throat.

Question 4

What do goblet cells produce?

Answer 4

Goblet cells produce mucous.

Question 5

What are clara cells?

Answer 5

Clara cells are non-ciliated, major cells of terminal bronchioles with the highest levels of P450 enzymes that differentiate into other cell types and secrete surfactant/mucous.

Question 6

What is the function of type 1 alveolar pneumocytes?

Answer 6

Type 1 alveolar pneumocytes cover large surface areas for gas exchange.

Question 7

What do type 2 alveolar pneumocytes secrete?

Answer 7

Type 2 alveolar pneumocytes secrete surfactant proteins that maintain the openness of the lungs.

Question 8

What do smooth muscle cells control?

Answer 8

Smooth muscle cells control the diameter of the airways.

Question 9

What is the resting breathing rate?

Answer 9

The resting breathing rate is 12-20 bpm.

Question 10

What happens during inhalation?

Answer 10

The diaphragm and ribs contract, causing the lungs to passively expand and elastically contract; gas exchange follows gradients.

Question 11

What are the ventilatory subunits of the lungs?

Answer 11

The ventilatory subunits of the lungs are alveoli, tiny sacs of air with associated capillaries.

Question 12

What does the gas exchange region consist of?

Answer 12

The gas exchange region consists of terminal bronchioles, alveolar ducts, alveoli, blood vessels, and lung interstitium.

Question 13

What are the major cell types of the alveoli?

Answer 13

The major cell types of the alveoli include type I pneumocytes, type II pneumocytes, capillaries, and interstitium.

Question 14

What allows us to assess homogeneity in healthy lung tissue?

Answer 14

Functional imaging allows us to assess homogeneity in healthy lung tissue.

Question 15

What does Xe129 allow?

Answer 15

Xe129 allows visualization of the lung airways.

Question 16

What can the Ga68-CBP8 probe label?

Answer 16

The Ga68-CBP8 probe can label collagen, which shouldn’t be seen in healthy lungs.

Question 17

What accompanies the decline of lung function?

Answer 17

The decline of lung function is accompanied by histological changes in the lungs.

Question 18

What is pneumoconiosis?

Answer 18

Pneumoconiosis is a lung disease caused by inhalation of dust leading to interstitial fibrosis.

Question 19

What is silicosis?

Answer 19

Silicosis is caused by silica (SiO2) exposure from quartz mining, masonry, and sandblasting.

Question 20

What is asbestosis?

Answer 20

Asbestosis is caused by asbestos exposure in manufacturing and construction.

Question 21

What is byssinosis?

Answer 21

Byssinosis is caused by inhalation of plant particles such as cotton, hemp, and flax.

Question 22

What is the acute airway response?

Answer 22

The acute airway response is the reflexive contraction of smooth muscle cells after toxicant exposure, leading to decreased airflow and increased mucous secretion.

Question 23

What characterizes chronic airway response?

Answer 23

Chronic airway response is characterized by increased sensitivity to bronchoconstriction, leading to asthma and reduced lung elasticity.

Question 24

What is chronic obstructive pulmonary disease (COPD)?

Answer 24

COPD is a progressive irreversible obstruction of airflow.

Question 25

What is the effect of asbestos exposure?

Answer 25

Asbestos exposure can lead to lung cancer, asbestosis, and mesothelioma.

Question 26

What is mesothelioma?

Answer 26

Mesothelioma is cancer of the protective pleural mesothelium lining of the lungs, not related to smoking.

Question 27

What are the three main mechanisms of asbestos toxicity?

Answer 27

The three main mechanisms of asbestos toxicity are surface Fe reactivity inducing ROS, activation of alveolar macrophages, and overproduction of ROS in mitochondria.

Question 28

What does asbestos induce?

Answer 28

Asbestos induces free radical production.

Question 29

What does paramagnetic resonance spectrometry detect?

Answer 29

Paramagnetic resonance spectrometry detects unpaired electrons/free radical production.

Question 30

What happens to free radicals in the presence of EDTA or DES chelators?

Answer 30

No free radicals are detected in the presence of EDTA or DES chelators.

Question 31

What do both asbestos types create in the presence of H2O2?

Answer 31

Both asbestos types create hydroxyl radicals in the presence of H2O2 and a reducing agent.

Question 32

What does asbestos induce in alveolar macrophages?

Answer 32

Asbestos induces apoptosis via p53 activation.

Question 33

What prevents asbestos-induced p53 apoptosis?

Answer 33

Pre-treatment with phytic acid or iron chelator prevents asbestos-induced p53 apoptosis.

Question 34

What role do alveolar macrophages play?

Answer 34

Alveolar macrophages play a role in pro-inflammatory signaling.

Question 35

What happens during frustrated phagocytosis?

Answer 35

Frustrated phagocytosis traps macrophages in lung tissue, leading to pro-inflammatory trigger release.

Question 36

What are the end results of pro-inflammatory signaling from macrophages bursting?

Answer 36

The end results are fibrosis and cancer.

Question 37

What can induce mitochondrial ROS production?

Answer 37

Asbestos can induce mitochondrial ROS production in key cells, leading to fibrosis.

Question 38

What are major sources of asbestos-induced ROS production?

Answer 38

Major sources include macrophages, epithelial, and mesothelial cells.

Question 39

What reduces ROS production in the presence of asbestos?

Answer 39

Mitochondrial electron transport chain loss of function reduces ROS production.

Question 40

What happens when H2O2 production in mitochondria is blocked?

Answer 40

Blocking H2O2 production in mitochondria mitigates asbestosis.

Question 41

What happens to asbestos fibers that are internalized?

Answer 41

Internalized asbestos fibers may come into physical contact with mitochondria to cause effects.

Question 42

What is the role of TNF alpha in fibrosis?

Answer 42

TNF alpha is critical in facilitating the phase change from early to late phase in fibrosis.

Question 43

What causes environmental pollution?

Answer 43

Environmental pollution can supply ozone production.

Question 44

How is ozone generated?

Answer 44

Ozone is generated via photolysis of smog in the lower atmosphere.

Question 45

What are sources of NO2?

Answer 45

Sources of NO2 include burning fossil fuels, coal, and wood.

Question 46

What does ozone react with in the airways?

Answer 46

Ozone reacts with PUFAs in airways, propagating lipid radicals.

Question 47

What is the pro-inflammatory process stimulated by ozone?

Answer 47

The pro-inflammatory process stimulated by ozone involves TNF alpha, which can trigger death receptor signaling.

Question 48

What are the characteristics of sulfur dioxide (SO2)?

Answer 48

SO2 is colorless, pungent, very water-soluble, and carcinogenic.

Question 49

What happens when SO2 reacts with singlet oxygen?

Answer 49

SO2 + singlet oxygen produces SO3 free radicals, leading to lipid peroxidation.

Question 50

What is the effect of aerosolized silica on lung function?

Answer 50

Aerosolized silica is associated with decreased FEV1 and FVC and higher PEF but shorter duration.