contractile vacuole

noun

, Cell Biology.

1. a membrane-enveloped cellular organelle, found in many microorganisms, that periodically expands, filling with water, and then contracts, expelling its contents to the cell exterior: thought to be important in maintaining hydrostatic equilibrium.

Word History and Origins

Origin of contractile vacuole¹

First recorded in 1875–80

Example Sentences

Waste nitrogenous products formed within the cell when work is done are passed out by means of the contractile vacuole.

From Project Gutenberg

Contractile vacuole absent; the nucleus is spherical and contains many large chromatin granules.

From Project Gutenberg

The nucleus is minute and lateral in position; the contractile vacuole is in the posterior end of the body.

From Project Gutenberg

The flagellum is inserted in a distinct œsophageal tube, into which the contractile vacuole empties.

From Project Gutenberg

The contractile vacuole is in the anterior neck-like portion of the body.

From Project Gutenberg