cytoplasm

American  

[sahy-tuh-plaz-uhm] / ˈsaɪ təˌplæz əm /

noun

Cell Biology.

1. the cell substance between the cell membrane and the nucleus, containing the cytosol, organelles, cytoskeleton, and various particles.

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cytoplasm British  

/ ˈsaɪtəʊˌplæzəm /

noun

1. the protoplasm of a cell contained within the cell membrane but excluding the nucleus: contains organelles, vesicles, and other inclusions

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cytoplasm Scientific  

/ sī′tə-plăz′əm /

1. The jellylike material that makes up much of a cell inside the cell membrane, and, in eukaryotic cells, surrounds the nucleus. The organelles of eukaryotic cells, such as mitochondria, the endoplasmic reticulum, and (in green plants) chloroplasts, are contained in the cytoplasm. The cytoplasm and the nucleus make up the cell's protoplasm.

2. See more at cell

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cytoplasm Cultural  

1. The material within a biological cell that is not contained in the nucleus or other organelles.

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Other Word Forms

• cytoplasmic adjective
• cytoplasmically adverb

Etymology

Origin of cytoplasm

First recorded in 1870–75; cyto- + -plasm

Compare meaning

How does cytoplasm compare to similar and commonly confused words? Explore the most common comparisons:

• cytosol vs. cytoplasm
• protoplasm vs. cytoplasm

Explanation

The human body is made up of cells, and within every cell is a nucleus — everything else contained within the cell walls is the cytoplasm. This is one of many technical terms for the little building blocks of life within us all. Cytoplasm consists of all the substances within the cell walls but outside of the nucleus: a fluid called cytosol, organelles such as the mitochondria, and tiny particles in suspension called inclusions. Cytoplasm is full of proteins, which are essential to your body. Cytoplasm is also called protoplasm. To see cytoplasm, you'll need a good microscope. To understand cytoplasm, you'll need a good biology teacher.

Example Sentences

When the same enzyme was restricted to the cytoplasm, it influenced entirely different cellular pathways.

From Science Daily • Mar. 9, 2026

Because microtubules can influence how stiff the cytoplasm is, the researchers asked whether asters might help anchor the actin band by stiffening the cell interior.

From Science Daily • Feb. 28, 2026

Rather than completing division in a single cycle, the cell achieves it step by step through alternating physical states of the cytoplasm.

From Science Daily • Feb. 28, 2026

Rather than destroying its host, the virus may have established a stable presence in the cytoplasm.

From Science Daily • Feb. 19, 2026

There they are, moving about in my cytoplasm, breathing for my own flesh, but strangers.

From "The Lives of a Cell" by Lewis Thomas