1
Week 6 Case Study: Chronic Obstructive Pulmonary Disease (COPD)
BIO255: Anatomy & Physiology III w/Lab
, 2
1. How is ventilation different from respiration?
Ventilation is the process that facilitates respiration. Hence ventilation is the inhalation
and exhalation of gases, Oxygen, and Carbon dioxide between the lungs and the
atmosphere. In contrast, respiration is the exchange of gases between the alveoli(found in
the lungs) and the blood in the pulmonary capillaries across the respiratory membrane
(i.e., in the body).
2. Ventilation is dependent upon a pressure gradient. Describe how this
pressure gradient works.
The pressure gradient is necessary to transport the air from the mount (or nose) to
pulmonary alveoli; hence, ventilation depends on a pressure gradient. The inward
movement of air(inspiration) from outside to lungs and outward air movement
(expiration) from lungs to outside atmosphere occurs because of the pressure gradient.
Therefore during inspiration, the contraction of the diaphragm causes a pressure gradient
between the lungs and atmosphere. Contraction of the diaphragm creates a negative
pressure inside the lungs, so air movement occurs from high pressure(atmosphere) to the
low atmosphere (lungs). Whereas in expiration, the relaxation of the diaphragm also
creates a pressure gradient relaxation of the diaphragm causes more pressure inside the
lungs. Hence, the air moves from inside of the lungs to outside to the atmosphere. Thus,
fall on Boyle’s law, "pressure exerted by a gas in a close container is inversely
proportional to the volume of the gas in the container." Inversely proportional means that
Week 6 Case Study: Chronic Obstructive Pulmonary Disease (COPD)
BIO255: Anatomy & Physiology III w/Lab
, 2
1. How is ventilation different from respiration?
Ventilation is the process that facilitates respiration. Hence ventilation is the inhalation
and exhalation of gases, Oxygen, and Carbon dioxide between the lungs and the
atmosphere. In contrast, respiration is the exchange of gases between the alveoli(found in
the lungs) and the blood in the pulmonary capillaries across the respiratory membrane
(i.e., in the body).
2. Ventilation is dependent upon a pressure gradient. Describe how this
pressure gradient works.
The pressure gradient is necessary to transport the air from the mount (or nose) to
pulmonary alveoli; hence, ventilation depends on a pressure gradient. The inward
movement of air(inspiration) from outside to lungs and outward air movement
(expiration) from lungs to outside atmosphere occurs because of the pressure gradient.
Therefore during inspiration, the contraction of the diaphragm causes a pressure gradient
between the lungs and atmosphere. Contraction of the diaphragm creates a negative
pressure inside the lungs, so air movement occurs from high pressure(atmosphere) to the
low atmosphere (lungs). Whereas in expiration, the relaxation of the diaphragm also
creates a pressure gradient relaxation of the diaphragm causes more pressure inside the
lungs. Hence, the air moves from inside of the lungs to outside to the atmosphere. Thus,
fall on Boyle’s law, "pressure exerted by a gas in a close container is inversely
proportional to the volume of the gas in the container." Inversely proportional means that
