Society and Health - Carbon Dioxide Transport and Gas Exchange

These flashcards cover key concepts from the lecture on carbon dioxide transportation and gas exchange, ensuring a comprehensive review for the exam.

How is carbon dioxide transported in the blood?

CO2 is transported in blood in three forms: dissolved, as bicarbonate, and as carbamino compounds.

What is the significance of Henry's Law in CO2 transport?

Henry's law states that CO2 is about 20 times more soluble than O2 in blood.

What enzyme significantly speeds up the reaction forming bicarbonate in red blood cells (RBCs)?

Carbonic anhydrase.

What is the chloride shift?

The exchange of bicarbonate (HCO3-) for chloride (Cl-) in red blood cells as CO2 is transported.

What describes the formation of carbamino compounds?

Carbamino compounds are formed by the combination of CO2 with terminal amines in blood proteins, especially hemoglobin (Hb).

What is the Haldane effect?

Deoxygenated blood can carry more CO2 than oxygenated blood, allowing for efficient CO2 transport.

What does the Bohr effect describe?

The Bohr effect explains how increased levels of CO2 and H+ reduce hemoglobin's affinity for O2 in active tissues.

What is the normal range for the Respiratory Exchange Ratio (R)?

The normal value for R is between 0.8 and 0.85.

How does the Respiratory Exchange Ratio change with diet?

R is 1.0 when carbohydrates are the predominant fuel source and 0.7 when fats are predominant.

What is anatomical dead space?

Anatomical dead space refers to the conducting zones of the respiratory system where no gas exchange occurs.

How is physiological dead space defined?

Physiological dead space is the sum of anatomical dead space and any alveolar dead space.

What are the two methods used to measure dead space?

Fowler’s method for anatomical dead space and Bohr’s method for physiological dead space.

What characterizes Fowler’s method?

Fowler’s method involves the measurement of nitrogen concentration in exhaled air to determine anatomical dead space.

What is the equation used in Bohr’s method to calculate dead space?

VD/VT = (FACO2 - FECO2) / FACO2.

What physiological role does carbonic anhydrase serve in red blood cells?

Carbonic anhydrase accelerates the conversion of CO2 and H2O to bicarbonate and protons.

What does the CO2 equilibrium curve indicate compared to the O2 curve?

The CO2 curve is more linear and steeper than the O2 curve, indicating greater changes in CO2 content with pressure changes.

Explain the relationship between O2 saturation and CO2 content in blood.

The lower the O2 saturation of hemoglobin, the greater the CO2 content for a given PCO2.

What effect does the Haldane effect have in the lungs?

In the lungs, loading of oxygen helps blood give up CO2 due to decreased affinity of hemoglobin for CO2.

How does the body calculate CO2 output?

CO2 output is calculated as the difference between CO2 expired and CO2 inspired.

What is the role of aquaporins in gas exchange?

Aquaporins facilitate the passage of CO2 across cell membranes.

What contributes to the physiological dead space in individuals with lung disease?

Ventilation-perfusion mismatching increases physiological dead space in lung disease.

What factors determine oxygen consumption in the body?

Body size and activity level determine oxygen consumption.

What is the average basal oxygen consumption for an adult?

Approximately 250 ml/min.

What is the relationship between tidal volume and dead space (VD)?

Tidal volume (VT) can be divided into alveolar ventilation (VA) and dead space (VD) volume.

What happens to the affinity of hemoglobin for O2 at high CO2 and H+ levels?

The affinity of hemoglobin for O2 decreases at high CO2 and H+ levels, promoting oxygen unloading.

Discuss the relevance of carbon dioxide's solubility in blood.

CO2's high solubility in blood allows for effective transport from tissues to the lungs.

What is the main method for measuring alveolar ventilation?

Alveolar ventilation can be determined by subtracting dead space ventilation from total ventilation.

Identify the main components of total CO2 in arterial and venous blood.

Total CO2 includes dissolved CO2, bicarbonate (HCO3-), and carbamino compounds.

What is the physiological significance of the venous-arterial difference in CO2?

The venous-arterial difference reflects the effectiveness of CO2 transport and exchange in the lungs.