The alveoli of mammalian lungs do not contain 20.9% O2 (that is, the percentage of O2 in atmospheric dry air) because    A. there is dead space in the trachea and bronchial tree and the air in the lungs is humidified.   B. mammals do not normally ventilate the lungs at a high enough rate.   C. the trachea and bronchi are too small in volume to contain this amount of O2.   D. mammal lungs have too many alveoli to ventilate.   E. some O2 has been exchanged with the blood before reaching the alveoli.

Which is/are false?   a. Carbaminohemoglobin is hemoglobin bound to carbon dioxide   b. In the lungs, the oxyhemoglobin saturation curve undergoes a 'left shift'   c. At a PO2 of 10 mmHg, there is more deoxyhemoglobin in blood that oxyhemoglobin   d. Higher temperatures and lower pH cause hemoglobin to bind more readily with oxygen than in conditions of lower temperatures and higher pH

The oxyhemoglobin dissociation (saturation) curve shifts to the right as the blood becomes more acidic. Under these conditions answer the following. At a P O2 = 40 mmHg the percent saturation of hemoglobin __________ and the content of oxygen bound to hemoglobin ____________.     A. Decreases; decreases   B. Increases; increases   C. Increases; decreases   D. Decreases; increases   E. Does not change; does not change

Which of the following statements regarding hemoglobin (Hb) saturation are true? a. On top of Everest Hb is less than 20% saturated b.   A leftward shift of the Hb-O2 dissociation curve causes more O2 to be off-loaded from Hb at any given PO2   c. Athletes competing at sea level should breathe 100% O2 to increase Hb saturation d. More than one of the above are correct

O2 bound to hemoglobin:   a. acts the same as physically dissolved oxygen   b. Comes off the hemoglobin (dissociates) more easily as you increase the oxygen partial pressure   c. exerts a partial pressure    d. Comes off the hemoglobin (dissociates) more easily as you increase the acidity (decrease the pH)   e. all the options are correct   2. Air convection in mammals is driven by a smaller pressure gradient than blood convection because:   a. Bronchioles have a greater resistance to flow than arterioles   b. bronchioles tend to have a smaller radius than arterioles and capillaries   c. air is easier to move with pressure gradients than blood    d. air generally travels farther in your body than does blood   e. air is heavier than blood 3. The rate of diffusion of gases is NOT determined by which of the following?   a. The area of the surface across which diffusion is occurring    b. The mechanical energy…

Oxygen diffuses from the inhaled air in the alveoli of the lungs, where its concentration is higher, into the cytoplasm of red blood cells, where its concentration is lower. Patients diagnosed with emphysema have damaged alveoli. This results to fewer, larger air spaces instead of many small ones. Explain how this damage can lead to shortness of breath? The surface area of lungs is reduced. Hence, less oxygen can diffuse into the red blood cells. The surface area of lungs is increased. Hence, more oxygen can diffuse into the red blood B cells. The surface area of lungs is reduced. Hence, more oxygen can diffuse into the red blood cells. The surface area of lungs is increased. Hence, less oxygen can diffuse into the red blood cells.

In the absence of 2,3-bisphosphoglycerate, the binding of oxygen by hemoglobin:   a. is characterized by cooperativity   b. resembles that of myoglobin   c. binds at the end of the hemoglobin molecule   d. is stabilized as the deoxy conformation of hemoglobin for the release into capillaries