Question

In: Anatomy and Physiology

how do the partial pressures of oxygen and carbon dioxide in blood change during alveolar gas...

how do the partial pressures of oxygen and carbon dioxide in blood change during alveolar gas exchange? what about during systemic gas exchange?

Solutions

Expert Solution

When blood passes through pulmonary capillary, RBC is exposed to oxygen only for 0.75 second at rest and only for 0.25 second during severe exercise. So, diffusion of oxygen must be quicker and effective. Fortunately, this is possible because of pressure gradient. Partial pressure of oxygen in the pulmonary capi­llary is 40 mm Hg and in the alveoli, it is 104 mm Hg. Pressure gradient is 64 mm Hg. It facilitates the diffusion of oxygen from alveoli into the blood.

Partial pressure of carbon dioxide in alveoli is 40 mm Hg whereas in the blood it is 46 mm Hg. Pressure gradient of 6 mm Hg is responsible for the diffusion of carbon dioxide from blood into the alveoli.

Systemic gas exchange means exchange of gases between blood capillaries and tissue cells.   
EXCHANGE OF RESPIRATORY GASES AT TISSUE LEVEL
Oxygen enters the cells of tissues from blood and carbon dioxide is expelled from cells into the blood.
DIFFUSION OF OXYGEN FROM BLOOD INTO THE TISSUES
Partial pressure of oxygen in venous end of pulmonary capillary is 104 mm Hg. However, partial pressure of oxygen in the arterial end of systemic capillary is only 95 mm Hg. It may be because of physiological shunt in lungs. Due to venous admixture in the shunt, 2% of blood reaches the heart without being oxygenated. Average oxygen tension in the tissues is 40 mm Hg. It is because of continuous metabolic activity and constant utilization of oxygen. Thus, a pressure
gradient of about 55 mm Hg exists between capillary blood and the tissues so that oxygen can easily diffuse into the tissues . Oxygen content in arterial blood is 19 mL% and in the venous blood, it is 14 mL%. Thus, the diffusion of oxygen from blood to tissues is 5 mL/100 mL of blood.
DIFFUSION OF CARBON DIOXIDE FROM TISSUES INTO THE BLOOD
Due to continuous metabolic activity, carbon dioxide is produced constantly in the cells of tissues. So, the partial pressure of carbon dioxide is high in the cells and is about 46 mm Hg. Partial pressure of carbon dioxide in arterial blood is 40 mm Hg. Pressure gradient of 6 mm Hg is responsible for the diffusion of carbon dioxide from tissues to the blood .Carbon dioxide content in arterial blood is 48 mL%. And in the venous blood, it is 52 mL%. So, the diffusion of carbon dioxide from tissues to blood is 4 mL/100 mL of blood.


Related Solutions

Describe how oxygen and carbon dioxide are carried in the blood, and explain the role of...
Describe how oxygen and carbon dioxide are carried in the blood, and explain the role of hemoglobin.
Gas Transport in the Blood. Describe in detail how carbon dioxide is transported in the blood....
Gas Transport in the Blood. Describe in detail how carbon dioxide is transported in the blood. Be sure to include all the ways the blood transports carbon dioxide and a detailed explanation/description of how carbon dioxide is “loaded” and “unloaded” from the blood both in the tissues and the alveoli.
2. How are oxygen and carbon dioxide are transported in the blood? 3. Hyperventilation is used...
2. How are oxygen and carbon dioxide are transported in the blood? 3. Hyperventilation is used by swimmers before they dive. Why? Also, why is that fatal? 4. What happens to the cardiac output when there is a tamponade (buildup of pericardial fluid)? Why is this fatal?
1) How are oxygen and carbon dioxide transported in the blood. 2) Give an illustrated account...
1) How are oxygen and carbon dioxide transported in the blood. 2) Give an illustrated account of the structure and function of the gas exchange region of the lung.
Explain what partial pressure is. List the partial pressures of O2 and CO2 in alveolar air...
Explain what partial pressure is. List the partial pressures of O2 and CO2 in alveolar air and explain what determines their values (discuss each gas separately). List the partial pressures of O2 and CO2 in systemic arterial blood and explain what determines their values. List the partial pressures of O2 and CO2 in systemic venous blood and explain what determines their values.
Explain why the partial pressure of oxygen decreases and carbon dioxide increases from their values in...
Explain why the partial pressure of oxygen decreases and carbon dioxide increases from their values in the atmosphere to air within the alveoli.
39. Oxygen diffuses from lungs to blood and carbon dioxide diffuses from blood to lungs
39. Oxygen diffuses from lungs to blood and carbon dioxide diffuses from blood to lungs a) pulmonary ventilation b) external respiration c) transport d) internal respiration 40. Which of the ekg waves represents ventricular depolarization (contraction) a) QRS complex b) P wave c) T wave d) S wave 41. Which of the ekg waves represents ventricular repolarization (recharging) a) QRS complex b) P wave c)T wave d) S wave
explain how oxygen and carbon dioxide are exchanged in the alveoli sac
explain how oxygen and carbon dioxide are exchanged in the alveoli sac
When methane (CH4) burns, it reacts with oxygen gas to produce carbon dioxide and water. The...
When methane (CH4) burns, it reacts with oxygen gas to produce carbon dioxide and water. The unbalanced equation for this reaction is CH4(g)+O2(g) → CO2(g)+H2O(g) This type of reaction is referred to as a complete combustion reaction. B. What mass of carbon dioxide is produced from the complete combustion of 5.00×10−3 (g) of methane? w/ units. C. What mass of water is produced from the complete combustion of 5.00×10−3 g of methane? w/ units. D. What mass of oxygen is...
When methane (CH4) burns, it reacts with oxygen gas to produce carbon dioxide and water. The...
When methane (CH4) burns, it reacts with oxygen gas to produce carbon dioxide and water. The unbalanced equation for this reaction is CH4(g)+O2(g)→CO2(g)+H2O(g) This type of reaction is referred to as a complete combustion reaction. Part B-What mass of carbon dioxide is produced from the complete combustion of 3.00×10−3 g of methane? Part C-What mass of water is produced from the complete combustion of 3.00×10−3 g of methane? Part D- What mass of oxygen is needed for the complete combustion...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT