Learning Objectives for Pulmonary and PV loops

Pressure Volume Loops 

Learning objectives          

1.    Describe the 3 factors that determine stroke volume of the ventricle.

2.    Diagram the relationship between ventricular pressure and ventricular volume during a complete cardiac cycle including the timing of valve opening/closings.

3.    Label the diastolic pressure, systolic pressure, end-diastolic volume, end-systolic volume, and stroke volume on a pressure-volume loop (define ejection fraction).

4.    Define stroke work and show how this is represented on a pressure-volume loop.

5.    Predict how stroke volume and the ventricular pressure/volume relationship will be affected by changes in:

Preload

Afterload

Inotropic State (Contractility)

Systolic Heart Failure

Diastolic Heart Failure

Ventilation

Learning Objectives

1.    Describe the functions of the respiratory system.

2.    Define the lung volumes and capacities and draw a spirogram labeling these volumes and capacities.

3.    Calculate physiological dead space using data for arterial and mixed expired PCO₂.

4.    Calculate alveolar ventilation in two ways: first, from respiratory rate, tidal volume, and dead space volume; second, from CO₂ production and arterial PCO₂.

5.    Calculate alveolar PCO₂ using data for metabolic rate and alveolar ventilation.

6.    Define hyper- and hypoventilation and describe the consequences on arterial blood gases and circulation.

 Gas Exchange

Learning Objectives

1.    Calculate inspired PO₂ from barometric pressure and %O₂.

2.    Calculate alveolar PO₂ from inspired PO₂ and alveolar (arterial) PCO₂.    

3.    Describe the factors that affect the diffusion of gases across the air-blood barrier.

4.    Describe the air-blood barrier and Fick’s law of diffusion across the air blood barrier.

5.    Define diffusing capacity (D_L) and describe how it changes with exercise and lung disease.

6.    Contrast perfusion limitation with diffusion limitation to gas exchange.

Pulmonary Circulation

Learning Objectives

1.    Describe the normal anatomical shunts that add venous blood to arterialized blood leaving the left ventricle.

2.    Compare the systemic and pulmonary circulations with respect to flows, driving pressures, and resistance.

3.    Identify the normal values for oxygen content and for systolic and diastolic pressures in the right atrium, right ventricle, pulmonary artery, and pulmonary artery occlusion (wedge) pressure.

4.    Calculate pulmonary vascular resistance and describe how it changes with alterations in pulmonary arterial pressure, lung volume, alveolar hypoxia, and autonomic NS stimulation.

5.    Describe the Starling-Landis equation, calculate net driving pressure and list the potential causes of pulmonary edema and pleural effusion.

6.    Describe the cause of ventilation – perfusion mismatch in normal lungs, the result in terms of regional blood gases, and the compensatory mechanisms to improve V/Q matching.

Blood Gas Transport

Learning Objectives

1.    Describe the normal values of O₂ in the pulmonary and systemic circulations in terms of PO₂, O₂ content, and O₂ saturation.

2.    Calculate oxygen content of blood from hemoglobin concentration and PO₂.

(not mentioned in lecture, but this is [Hb] g/dL x 1.34 mlO₂/g Hg; e.g., 10 g Hb/dL should provide 13.4 mlO₂/dL.  Dissolved O₂ = PO₂ x 0.003; e.g., PO₂ of 100 gives 0.3 ml/dL of dissolved O₂.

3.    Use the Fick principle to calculate cardiac output or oxygen uptake or arterial and venous O₂ content.  Describe the reserves available for increasing oxygen uptake using the Fick principle as applied to the heart and to skeletal muscles.

4.    Define P₅₀ and describe the important factors that shift the oxygen dissociation curve to the left and right.

5.    Describe the effects of carbon monoxide inhalation and anemia on arterial O₂ saturation, content, and PO₂.

6.    Describe the chemical forms of CO₂ transport from tissues to lungs and the relative importance (percentage) of each form.

7.    Define the chemical reactions that explain the interactions between the Bohr Effect and the Haldane effect.

Mechanics of Breathing

Learning Objectives

1.    Describes the muscles used for inspiration and expiration.

2.    Define compliance and describe the changes in compliance with obstructive, restrictive, and vascular lung diseases.

3.    Describe the synthesis and composition of surfactant and its role in stabilizing the lung.

4.    Describe the factors that are most important in determining airway resistance.

5.    Draw a flow-volume loop for a healthy person and for a person with obstructive and restrictive lung disease.  Identify vital capacity and residual volume on the loop.

6.    Draw a pressure volume loop for the lungs and label the work to overcome elastic resistance and flow resistance.

 Control of Breathing

Learning Objectives

1.    Describe the basic organization of respiratory control, identifying the major afferent and efferent influences.

2.    Discuss the differences between the roles of CO₂ and O₂ in control of breathing. 

3.    Describe the muscles used for normal, resting breathing and the accessory muscles available for inspiration and expiration.

4.    Describe the interaction of chemoreceptor stimuli on control of ventilation.

5.    Contrast the primary stimuli and relative importance of central and peripheral chemoreceptors.

Mechanisms of Arterial Hypoxemia

Learning Objectives

1. Describe the 4 types of hypoxia and the change in arterial PO₂ for each type.
2. Describe the 5 causes of arterial hypoxemia and how to differentiate them.
3. Explain why mismatching of ventilation and perfusion affects PO₂ more than PCO₂.
4. Contrast the levels of O₂ and CO₂ in blood from the top of the lung (high V/Q) and the bottom of the lung (low V/Q).
5. Describe the role of hypoxia inducible factor (HIF-1) in adaptations and pathobiology of chronic hypoxemia.