RGI 2 Notes

These flashcards cover key concepts related to the regulation of respiration and gas transport, including gas exchange mechanisms, the role of hemoglobin, and the effects of various physiological factors on respiration.

What is gas transport in the respiratory system?

The process by which gases like oxygen and carbon dioxide are exchanged between the alveoli and the blood.

What is the primary method of oxygen transport in blood?

Over 98% of oxygen is transported bound to hemoglobin.

What is the oxygen-utilization coefficient?

The fraction of oxygen that is utilized by tissues as blood passes through capillaries.

What is the significance of Dalton’s law of partial pressure?

It states that in a mixture of gases, the total pressure is the sum of the partial pressures of individual gases.

How is partial pressure of oxygen calculated at sea level?

Oxygen's partial pressure is calculated as 0.21 X 760 mm Hg = 160 mm Hg.

What is Fick’s law of diffusion?

It states that the amount of gas diffusing across a membrane depends on the partial pressure difference and the surface area of the membrane.

What is the definition of partial pressure?

The pressure exerted by an individual gas in a mixture.

What does a right shift in the oxygen-hemoglobin dissociation curve indicate?

Decreased affinity of hemoglobin for oxygen, facilitating oxygen release.

How does carbon dioxide affect blood pH?

Increased carbon dioxide concentration lowers pH, creating an acidic environment.

What is the Bohr effect?

The tendency of hemoglobin to release oxygen more readily when blood becomes more acidic.

How is carbon dioxide transported in the blood?

As dissolved gas in plasma, bound to proteins, particularly hemoglobin, or as bicarbonate ions.

What does the term 'Haldane effect' refer to?

The increased release of carbon dioxide from blood when it is oxygenated.

What is the oxygen-hemoglobin dissociation curve?

A graph that shows the relationship between oxygen saturation of hemoglobin and the partial pressure of oxygen.

What role does carbonic anhydrase play in CO2 transport?

It catalyzes the conversion of CO2 and water into carbonic acid within red blood cells.

What is the primary mechanism for oxygen transport in the blood?

Binding to hemoglobin in red blood cells.

What is the normal arterial PO2 in healthy individuals?

Approximately 100 mm Hg.

What is the effect of exercise on oxygen utilization?

Increased oxygen delivery and utilization by tissues, potentially up to 75% of blood's oxygen capacity.

What is the significance of hemoglobin in oxygen transport?

It increases the oxygen carrying capacity of blood significantly beyond what is dissolved in plasma.

How does a left shift in the oxygen-hemoglobin dissociation curve affect oxygen binding?

Increases hemoglobin's affinity for oxygen, making it harder to release oxygen.

What is the description of the oxygen transport forms in blood?

Oxygen is present physically dissolved in plasma and chemically combined with hemoglobin.

What influences the shift in the oxygen-hemoglobin dissociation curve?

Factors like pH, carbon dioxide concentration, 2,3-DPG, and temperature.

How is carbon dioxide primarily transported as bicarbonate ion?

About 75% of carbon dioxide is transported as bicarbonate (HCO3-) in blood.

What is the chloride shift?

The exchange of bicarbonate ions out of red blood cells for chloride ions from plasma.

What happens to bicarbonate ions in the lungs?

Bicarbonate is converted back to CO2, which is expelled during exhalation.

What is the average venous blood oxygen content post-utilization?

Approximately 15 ml O2 per 100 ml blood remains after passing tissue capillaries.

What is the relationship between carbon dioxide and blood acidity?

Higher carbon dioxide concentration leads to increased acidity and lower pH.

What is the carbon dioxide dissociation curve?

A graph showing the relationship between carbon dioxide content and partial pressure of CO2.

What factors increase the release of oxygen from hemoglobin according to the Bohr effect?

Increased carbon dioxide and decreased pH levels in the blood.

What is carbaminohemoglobin?

A compound formed when carbon dioxide binds to hemoglobin at a site different from oxygen.

At what pressure does carbon dioxide become more concentrated in the blood compared to alveolar air?

PCO2 is approximately 45 mm Hg in venous blood, compared to lower values in alveolar air.

What is the normal pH range of arterial blood?

The pH range of normal arterial blood is approximately 7.35 to 7.45.

What is the maximum amount of oxygen hemoglobin can transport?

It can bind up to four oxygen molecules per hemoglobin molecule.

How does altitude affect partial pressure of gases?

At high altitudes, the partial pressure of oxygen decreases, affecting oxygen availability.

What is the fate of carbon dioxide produced in metabolically active tissues?

It is transported back to the lungs for removal from the body.

What type of curve describes the relationship between carbon dioxide concentration and its partial pressure?

The carbon dioxide dissociation curve.

How does 2,3-DPG affect hemoglobin's function?

It decreases the affinity of hemoglobin for oxygen, aiding in oxygen release.

Why is oxygen poorly soluble in blood?

Oxygen solubility in blood is only about 0.25 mL / 100 mL blood.

How does increased temperature affect oxygen release by hemoglobin?

Increased temperature promotes oxygen release, shifting the curve right.

What happens to the oxygen partial pressure in tissues during gas exchange?

Tissue PO2 decreases, facilitating oxygen diffusion from blood into cells.

What is the significance of maintaining a steep alveolar PO2 gradient?

It ensures efficient diffusion of oxygen from alveoli into the blood.

What can occur if excess hydrogen ions are released from carbonic acid in blood?

They can lead to acidosis if not buffered effectively by hemoglobin.

How does blood's ability to carry carbon dioxide change during oxygenation?

Oxygenation of blood decreases its capacity to carry carbon dioxide.