A&P Neurophysiology Practice Test 2026 – Complete Exam Preparation

Astrocytes play a crucial role in the central nervous system by supporting and maintaining the integrity of the blood-brain barrier. This barrier is vital for protecting the brain from harmful substances while allowing essential nutrients to pass through. Astrocytes contribute to the formation and maintenance of this barrier by regulating the transport of ions and nutrients across the endothelial cells that make up the blood-brain barrier. Additionally, they help to maintain the extracellular environment, ensuring that neurotransmitter levels are appropriate for optimal neuronal function.

The other functions mentioned, such as transmitting nerve impulses, producing neurotransmitters, or insulating axons with myelin, are primarily associated with other types of cells. For instance, neurons are responsible for the transmission of nerve impulses, whereas oligodendrocytes and Schwann cells are responsible for myelination in the central and peripheral nervous systems, respectively. Therefore, the primary function of astrocytes is correctly identified as supporting and maintaining the blood-brain barrier, highlighting their essential role in protecting and nourishing the brain.