What is the process called for measuring tissue components with the light microscope?

• A. Micrometry
• B. Histometry
• C. Planimetry
• D. Calometry

Answer: (A)

Measuring tissue components with a light microscope is called micrometry. It uses an ocular micrometer inside the eyepiece, which is calibrated against a stage micrometer to convert eyepiece units into actual dimensions, usually micrometers. This method lets you quantify linear dimensions such as cell and nucleus diameters, lengths, or diameters of fibers. Planimetry, by contrast, measures areas by tracing outlines on sections or micrographs, and histometry refers to quantitative analysis of tissue but is broader than just linear measurements. Calometry isn’t a standard term in histology.