Final answer:
a. astrocytes. Astrocytes are neuroglia that control the chemical environment around neurons by buffering potassium and recapturing neurotransmitters.
Step-by-step explanation:
Neuroglia that control the chemical environment around neurons by buffering potassium and recapturing neurotransmitters are astrocytes.
There are several types of glial cells in the nervous system, and in the central nervous system (CNS), astrocytes are responsible for maintaining the chemical environment around neurons. They regulate the concentrations of ions and chemicals in the extracellular fluid, provide structural support for synapses, and form the blood-brain barrier to block toxic substances from entering the brain. Astrocytes also have the ability to become active in response to nerve activity, transmit calcium waves between astrocytes, and modulate the activity of surrounding synapses.