Alveoli are tiny, balloon-shaped air sacs that sit at the very end of the respiratory tree, branching off the _______.

1. tertiary bronchi	2. bronchioles
3. terminal bronchioles	4. respiratory bronchioles

The cells lining the alveoli that secrete the pulmonary surfactant are:
1. type I alveolar cells
2. type II alveolar cells
3. filtration from the alveolar capillaries
4. alveolar macrophages

A measure of the amount of air a person inhales during a normal breath is:

2,3-diphosphoglycerate in red blood cells:
1. enhances oxygen unloading at the systemic capillaries
2. makes deoxyhemoglobin less stable
3. shifts the oxyhemoglobin dissociation curve to the left
4. stimulates the production of more red blood cells

Four globin chains [ 2 alpha and 2 gamma] constitute the structure of:
1. hemoglobin A
2. hemoglobin F
3. hemoglobin S
4. methemoglobin

The abnormal hemoglobin seen in patients of sickle cell anemia is HbS. It is different in structure from the normal HbA because:

The amount of air that remains in a person's lungs after fully exhaling is known as:

The basic rhythm of breathing is controlled by:
1. peripheral chemoreceptors
2. dorsal respiratory group of the medullary rhythmicity center
3. ventral respiratory group of the medullary rhythmicity center
4. pneumotaxic area

Gas exchange in the human lungs takes place across the respiratory membrane which is made up of:

The opening between the vocal folds is called: