Sr | Clues | Type | Functions |
1 | Extensions from these cells cover the blood vessels and capillaries. | Astrocytes | Astrocytes have extensions called end-feet that cover the blood vessels and capillaries in the brain. They play a crucial role in maintaining the blood-brain barrier, regulating nutrient and oxygen supply, and controlling the exchange of molecules between the bloodstream and the brain tissue. |
2 | Extensions from these cells wrap around the axons. | Oligodendrocytes (in the central nervous system) / Schwann cells (in the peripheral nervous system) | Oligodendrocytes in the central nervous system and Schwann cells in the peripheral nervous system are responsible for producing myelin, a fatty substance that wraps around axons. Myelin acts as an insulating layer, increasing the speed and efficiency of electrical signal conduction along the axons. |
3 | These cells are small house cleaning staff for neurons. | Microglia | Microglia are the immune cells of the central nervous system. They act as the brain's resident immune cells and are involved in maintaining brain health, surveillant pathogens or abnormalities, and clearing dead cells, debris, and foreign substances through a process called phagocytosis. They also play a role in inflammation and immune responses within the brain. |
4 | These cells are the executors of dead cells and debris. | Phagocytes | Removal of cellular corpses is important in both homeostasis and disease. The engulfing of dead cells by professional phagocytes, a multistep process known as efferocytosis [G], allows multicellular organisms to recycle cellular components. |