Oncology & Cancer

Technique shows how individual cancer cells react to drugs

A new technique reported in Science this week overcomes several limitations of typical high-throughput chemical screens conducted on cell samples. Such screens are commonly used to try to discover new cancer drugs, and in ...

Neuroscience

Three types of cells help the brain tell day from night

Bright light at night interrupts the body's normal day-night cycles, called circadian rhythms, and can trigger insomnia. In fact, circadian rhythms play a major role in health. Disrupted day-night cycles have even been linked ...

Ophthalmology

Imaging of conjunctival goblet cells helps diagnosis of dry eyes

Goblet cells are epithelial cells that produce mucins and disperse tears which help the surface of eyes maintain their wet environment. Goblet cells are closely related to autoimmune diseases including dry eyes and chemical ...

Neuroscience

Why nerve cells in the brain process information differently

The dentate gyrus is the "input point" for the hippocampus part of the brain. It transmits information from the short term memory to the long term. It consists of granule cells, which are especially dense in this area of ...

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Cell (biology)

The cell is the structural and functional unit of all known living organisms. It is the smallest unit of an organism that is classified as living, and is often called the building block of life. Some organisms, such as most bacteria, are unicellular (consist of a single cell). Other organisms, such as humans, are multicellular. (Humans have an estimated 100 trillion or 1014 cells; a typical cell size is 10 µm; a typical cell mass is 1 nanogram.) The largest known cell is an unfertilized ostrich egg cell.

In 1835 before the final cell theory was developed, a Czech Jan Evangelista Purkyně observed small "granules" while looking at the plant tissue through a microscope. The cell theory, first developed in 1839 by Matthias Jakob Schleiden and Theodor Schwann, states that all organisms are composed of one or more cells. All cells come from preexisting cells. Vital functions of an organism occur within cells, and all cells contain the hereditary information necessary for regulating cell functions and for transmitting information to the next generation of cells.

The word cell comes from the Latin cellula, meaning, a small room. The descriptive name for the smallest living biological structure was chosen by Robert Hooke in a book he published in 1665 when he compared the cork cells he saw through his microscope to the small rooms monks lived in.

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