Pulmonary

Question 1

Pathology of cystic fibrosis

Answer 1

CF is an autosomal recessive disorder caused by mutations (e.g., ΔF508) in the CFTR gene. CFTR (cystic fibrosis transmembrane conductance regulator) is a protein that forms a chloride channel
* Normal function: Channel opens after binding 2 ATP molecules, allowing chloride ion transport down electrochemical gradient
* This movement creates a membrane potential that draws sodium and water across the membrane
CFTR normally hydrates mucosal surfaces in airways and bowel

Question 2

Logic behind the sweat chloride test

Answer 2

Question 3

X-Ray signs of congenital diaphragmatic hernia

Answer 3

With presence of bowel loops in the thorax

Question 4

Presentation of a neonate with CDH

Answer 4

Within minutes-hours of birth
Cyanosis
Dyspnea
Decreased breath sounds over affected area
Scaphoid abdomen

Question 5

What is cor pulmonale?

Answer 5

Cor pulmonale is a condition characterized by enlargement and failure of the right ventricle of the heart due to pulmonary hypertension (increased pressure in the pulmonary circulation). It occurs as a result of diseases affecting the lungs, pulmonary vessels, chest wall, or respiratory control.

Question 6

What is the genetic defect in cystic fibrosis?

Answer 6

Post-translational

Question 7

What kind of small bowel obstruction finding is very specific for CF?

Answer 7

Meconium ileus

Question 8

How does meconium ileus form?

Answer 8

Inspissated stool that has become extremely thick, dried out, and compacted due to excessive water absorption or dehydration.

Question 9

Distinguish between meconium ileus and Hirschsprung disease

Answer 9

Question 10

Electrolyte imbalance responsible for symptoms on a sleepy newborn with CFTR mutation

Answer 10

Hyponatremia

Question 11

Explain how the mucous becomes thickened in the airways in CF

Answer 11

Question 12

In cystic fibrosis, which vitamin deficiency mostly contributes to a potential squamous metaplasia of the pancreatic ducts?

Answer 12

Vitamin A

Question 13

Microbiology associated with cystic fibrosis

Answer 13

Question 14

Useful test in patients with suspected CF but negative sweat testing and how to interpret results

Answer 14

Nasal transepithelial potential difference.

Question 15

Is Cl- content in sweat test increased or decreased in cystic fibrosis?

Answer 15

Decreased

Question 16

Dinstinguish between two types of pneumocytes

Answer 16

Question 17

Where is airway resistance highest in the respiratory tree?

Answer 17

Larger airways
The smaller the airways, the more there are in parallel = less resistance

Question 18

Which zone is considered anatomic dead space?

Answer 18

The conducting zone.

Question 19

3 diaphragmatic structures and their levels

Answer 19

I ate 10 eggs at 12:

T8: IVC
T10: Esophagus
T12: Aortic hiatus

Question 20

Label the volumes on this graph

Answer 20

Question 21

Physiologic vs anatomical dead space

Answer 21

Approximately the same, except in diseases with ventilation/perfusion mismatch

Question 22

V/Q at apex vs at base of lung

Answer 22

Apex = 3 (wasted ventilation) - with exercise, there is vasodilation of apical capillaries such that V/Q approaches 1
Base = 0.6 (wasted perfusion)

Question 23

Hypoxia vs hypoxemia

Answer 23

Hypoxia = decreased O2 delivery to tissues. Due to decreased CO, hypoxemia, ischemia, anemia, CO poisoning.

Hypoxemia = insufficient oxygenation of blood (decreased PaO2)

Question 24

Affinity of Hb for O2 when oxygenated vs deoxygenated

Answer 24

Oxygenated = 300x binding affinity for O2.
Deoxygenated = low affinity, to promote release / unbinding of O2.

Question 25

Describe changes in O2 content of arterial blood, plasma O2 content, and Hb saturation of O2 in Anemia, Polycythemia, CO poisoning, methemoglobinemia

Answer 25

Question 26

Right shit vs left shift in Hb dissociation curve- what do they mean?

Answer 26

right shift = decreased Hb affinity for O2 = increased O2 unloading in tissues left shift = increased Hb affinity for O2 = decreased O2 unloading in tissues

Question 27

What causes right shift in HbO2 dissociation curve?

Answer 27

increased tissue needs for O2 1) decreased pH 2) increased temperature/fever 3) hypoxia (increased 2-3BPG)

Question 28

What causes left shift in HbO2 dissociation curve?

Answer 28

Decreased tissue needs for O2 1) decreased temperature 2) decreased 2-3BPG

Question 29

What happens to the HbO2 curve in pregnancy?

Answer 29

Left shift because fetal Hb has higher O2 affinity than adults due to fetal Hb having decreased affinity for 2-3BPG.

Question 30

Body's response to high altitute

Answer 30

Question 31

Histopathological findings of bronchopulmonary dysplasia (2)

Answer 31

Question 32

What is the Haldane effect (2 effects of O2 binding onto hemoglobin)

Answer 32

Question 33

Explain the concept of diffusion limited and in which type of lung disease it happens

Answer 33

In interstitial lung disease = fibrosis = increased transit time between O2 and capillary

Question 34

In which lobe is this pneumonia?

Answer 34

RUL

Question 35

In which lobe is this pneumonia?

Answer 35

RML

Question 36

Explain the relationship between hypercapnia, hypoxemia and cerebral blood flow

Answer 36

Question 37

Draw out the graph (in your head) of total airway resistance from the largest airways to the smallest

Answer 37

Question 38

Describe the changes in pulmonary function tests in normal aging in terms of residual volume, functional residual capacity and total lung capacity.

Answer 38

The lungs have **less elastic recoil** = increased alveolar compliance. This means that the alveoli have less of a tendency to empty themselves. As a result, RV increases and forced vital capacity decreases. **Total lung capacity remains the same**.

Question 39

What are the risk factors for acute respiratory distress syndrome?

Answer 39

Sepsis, severe trauma (fat emboli), transfusion of blood products

Question 40

What is ARDS?

Answer 40

Inflammatory reaction in the lungs leading to severe respiratory compromise and hypoxemia from **non-cardiogenic pulmonary edema**.

Question 41

Pathophysiology of ARDS

Answer 41

Question 42

Which type of pneumocyte has the capacity to proliferate in response to lung injury?

Answer 42

Type II pneumocytes (5% of all), which also make surfactant.

Question 43

What is the cause of this normal drop in O2 saturation between the pulmonary capillaries and the systemic arterial circulation?

Answer 43

Shunting from bronchial veins which drains into the pulmonary vein and thesebian (small cardiac) veins which drains directly into the left atrium

Question 44

(A) Arterial blood mean CO2 content (B) Arterial blood mean O2 content (C) Venous blood mean CO2 content (D) Venous blood mean O2 content

Answer 44

(C) Venous blood mean CO2 content Increased O2 consumption by muscle = increased CO2 production

Question 45

Name cells present in the respiratory tract in bronchi, proximal, terminal and respiratory bronchioles

Answer 45

Ciliated cells persist all the way to respiratory bronchioles (beyond mucous producing cells, so that they can clear mucous towards oropharynx if necessary)

Question 46

PaO2 and PaCO2 changes with normal aging

Answer 46

PaO2 decreases PaCO2 unchanged

Question 47

What is physiologic dead space?

Answer 47

Anatomic dead space + alveolar dead space

Question 48

Why is RBC chloride content elevated in venous blood ("chloride shift")?

Answer 48

The majority of CO2 is broken down to HCO3- by RBCs then exchanged for Cl- for the bicarbonate to be carried in plasma.

Question 49

Changes in V/Q during exercise

Answer 49

Up to 20x increase in ventilation Increase in cardiac output V increase > Q increase = increased V/Q

Question 50

Why does mixed venous O2 content diminish during exercise?

Answer 50

Question 51

Is ventilation or cardiac output the primary limitation to exercise?

Answer 51

CO!

Question 52

Which set of values would you expect in a high altitude camper after 2 days

Answer 52

Respiratory alkalosis that is partially compensated for by renal excretion of HCO3-