Chapter 22, Lesson 3: Gas Exchange and Transport

Flashcards from Chapter 22, Lesson 3 of McGraw Hill Anatomy and Physiology, Tenth Edition, by Kenneth S. Saladin.

Air composition

• 78.6% N

• 20.9% O₂

• 0.04% CO₂

• trace amounts of Ar, Ne, He, CH₄, O₃

Dalton’s law

The total atmospheric pressure is the sum of the contributions of the individual gases

Partial pressure

The separate contribution of each gas to pressure in a mixture

Alveolar gas exchange

The movement of O₂ and CO₂ across the respiratory membrane, using a film of water to cover the epithelium to dissolve oxygen and diffuse carbon dioxide

Hyperbaric oxygen therapy

Treatment with oxygen at greater than 1 atmosphere of pressure to allow more diffusion into the blood; used to treat gangrene and CO poisoning

Gas solubility

CO₂ is 20 times more soluble than O₂, CO₂ diffuses more rapidly

Membrane surface area

Can be decreased by emphysema, lung cancer, and tuberculosis

Membrane thickness

Only 0.5 um to allow for faster diffusion; greater will lead to slower travels (can be caused by pulmonary edema, pneumonia)

Gas transport

The process of carrying gases from the alveoli to the systemic tissues and vice versa

Oxyhemoglobin (HbO₂)

O₂ bound to hemoglobin

Deoxyhemoglobin (HHb)

Hemoglobin with no O₂

Carbon monoxide (CO)

A colorless, odorless gas in cigarette smoke, engine exhaust, and gas furnace fumes that competes for O₂ binding cites on hemoglobin; can be lethal

Venous reserve

The amount of O₂ remaining in the blood after passing through systemic capillary beds

Hypoxia

The deficiency or inability to use oxygen