Which function is attributed to astrocytes?

• A. Produce myelin in the CNS
• B. Provide structural and metabolic support for neurons and form the blood-brain barrier
• C. Phagocytose debris
• D. Transmit electrical signals

Answer: (B)

Astrocytes mainly provide structural and metabolic support to neurons and help form the blood-brain barrier. They help hold neurons in place and wrap around blood vessels, regulating the extracellular environment by balancing ions and clearing neurotransmitters. They also shuttle energy substrates from blood to neurons, supporting neural activity. Their endfeet on capillaries contribute to the blood-brain barrier by helping maintain tight junctions between endothelial cells. While other glial cells have different roles—oligodendrocytes make CNS myelin, microglia phagocytose debris—and neurons are the primary cells that transmit electrical signals, astrocytes are the key supporters that keep neuronal function stable and protected.