2.3 Respiratory Physiology Flashcards
What are the basic steps of respiration?
- breathing
- external respiration
- internal respiration
- aerobic cellular respiration
What does breathing include?
inspiration
expiration
What does external respiration include?
gas exchange with the environment at a respiratory surface
What does internal respiration include?
gas exchange between blood and tissue fluid
What is aerobic cellular respiration?
production of ATP
How does gas exchange take place?
diffusion
What is necessary for diffusion of gas to be efficient?
gas-exchange region needs to be
1. moist
2. thin
3. large in relation to the size of the body
What does the human body do to enhance the effectiveness of gas diffusion?
extensive vascularization of the lungs
How much water per day does a human lose when the air has a relative humidity of 50%?
350ml of water
What is the estimated total surface area of lungs as compared to skin?
fifty times of the skin’s surface
When does ventilation occur?
during inhalation and exhalation
What creates a negative pressure in the lungs?
pleural space
What occurs during inhalation?
rib cage lifts superiorly and anteriorly to open up and expand the lungs
diaphragm contracts and pulls lungs open
thoracic pressure decreases
What occurs during exhalation?
rib cage is lowered and diaphragm rises to increase the thoracic pressure
What does incomplete ventilation mean?
the lungs do not completely empty during each breathing cycle
