Definitions/Explanations:
Respiration: The entire process of gas exchange in the body; it includes each of the following:
1. Pulmonary Ventilation (AKA breathing): The follow of air into and out of the lungs. The result of muscle contraction of the diaphragm. Ventilation consists of two parts:
a. Inspiration: The process that occurs when atmospheric gas is drawn into the lungs by way of contraction of the diaphragm which causes expansion of the thoracic cavity thus reducing the pressure within the thoracic cavity, drawing air into the lungs.
b. Expiration: The process that occurs when the diaphragm relaxes, causing the pressure inside the thoracic cavity to increase, forcing air out of the lungs.
2. External Respiration: The exchange of gases between the air spaces (alveoli) of the lungs and the blood in the pulmonary capillaries. In this process, pulmonary capillary blood gains O2 and loses CO2.
3. Internal Respiration: The exchange of gases between blood in systemic capillaries and tissue cells. The blood loses O2 and gains CO2. Within cells, the metabolic reactions that consume O2 and give off CO2 during the production of ATP are termed cellular respiration.
Diaphragm: A dome shaped muscle that divides the thoracic and abdominal cavities that when contracted, makes the thoracic cavity larger. The primary muscle of respiration.
Alveoli: The air sacs in the lungs where gas exchange occurs between the atmosphere and the blood.
Partial Pressure: The proportion of pressure that a single gas exerts within a mixture.
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Forced Expiratory Volume (FEV1): The percentage of vital capacity exhaled during a 1-second period of the FVC text.
Inspiratory Reserve Volume: The amount of air that can be taken into the lungs beyond the tidal volume.
Expiratory Reserve Volume: The amount of air that can be expelled from the lungs beyond the tidal volume.
Tidal Volume: The volume
Links: Animations/Flash/0034-swf_alveolar_press.swf See the following site for an animation illustrating the basics of respiration: http://www.wisc-online.com/objects/index_tj.asp?objID=AP15104