1. Abbrev. for total acidity; ante; area; asymmetric; auris; artery; arteria; autopsy.

2. Symbol for atto-.

3. As a subscript, refers to systemic arterial blood.

4. Symbol for specific absorption coefficient. Abbrev. for absorptivity.

A

1. Abbrev. for ampere; adenine; alanine; Helmholtz energy.

2. As a subscript, refers to alveolar gas.

3. Symbol for absorbance.

4. Symbol for adenosine or adenylic acid in polynucleotides; alanine in polypeptides.