anoxia

Absence or almost complete absence of oxygen from inspired gases, arterial blood, or tissues; to be differentiated from hypoxia. [G. an- priv. + oxygen]

- anemic a. a term formerly considered synonymous with anemic hypoxia, but now reserved for extremely severe cases in which oxygen and functional erythrocyte volume are almost completely lacking.

- anoxic a. a term formerly considered synonymous with hypoxic hypoxia, but now reserved for extremely severe cases in which oxygen is almost completely lacking.

- diffusion a. diffusion hypoxia severe enough to result in the absence of oxygen in alveolar gas.

- histotoxic a. poisoning of the respiratory enzyme systems of the tissues, as in the inhibition of cytochrome oxidase by cyanides; owing to the inability of tissue cells to utilize oxygen, its tension in arterial and capillary blood is usually greater than normal.

- a. neonatorum any a. observed in newborn infants.

- oxygen affinity a. a. due to inability of hemoglobin to release oxygen.

- stagnant a. stagnant hypoxia severe enough to result in the absence of oxygen in tissues.

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an·ox·ia ə-'näk-sē-ə, a- n hypoxia esp. of such severity as to result in permanent damage

an·ox·ic -sik adj

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n.

a condition in which the tissues of the body receive inadequate amounts of oxygen. This may result from low atmospheric pressure at high altitudes; a shortage of circulating blood, red blood cells, or haemoglobin; or disordered blood flow, such as occurs in heart failure. It can also result from insufficient oxygen reaching the blood in the lungs due to poor breathing movements or because disease, such as pneumonia, is reducing the effective surface area of lung tissue. See also hypoxia.

• anoxic adj.

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anox·ia (ə-nokґse-ə) a total lack of oxygen; often used interchangeably with hypoxia to mean a reduced supply of oxygen to the tissues. anoxic adj