Meaning of astrocyte: Astrocytes are star shaped glial cells that support, nourish, and help regulate the environment surrounding neurons in the brain.

Definition of astrocyte

An astrocyte is a star-shaped cell found throughout the brain and spinal cord that belongs to a broader category of supportive cells called glial cells, distinct from the neurons that transmit electrical signals. Astrocytes physically hold neurons in place and provide structural support within the nervous system.

Beyond this structural role, astrocytes help regulate the chemical environment surrounding neurons, including managing levels of certain ions and neurotransmitters, and they contribute to forming the blood-brain barrier, a selective boundary that limits which substances can pass from the bloodstream into brain tissue. Astrocytes also assist in repairing tissue after injury to the brain or spinal cord.

Because astrocytes perform so many supportive functions, disruption of their normal activity has been linked to a range of neurological conditions, and tumors arising from astrocytes, called astrocytomas, form one of the more common categories of primary brain tumor.

Used in a sentence

Pathology identified astrocytes consistent with reactive changes surrounding the area of brain injury.

+

Good to know

Astrocytes are supportive glial cells rather than neurons, so their dysfunction affects the environment surrounding nerve cells rather than directly disrupting the electrical signals neurons use to communicate.

Word origin

Where “astrocyte” comes from

Formed from Greek astron, meaning star, and kytos, meaning cell.

For learning, not diagnosis. This glossary provides general educational information and is not a substitute for advice from a qualified healthcare professional. If you may be experiencing a medical emergency, contact local emergency services.