A 75-year-old man has a history of transient attacks of loss of vision. The only abnormalities on physical examination are bruits over the carotids in the neck. Two days later he suddenly becomes hemiplegic and loses consciousness. He is rushed to the emergency room and a CT scan shows evidence of cerebral infarction. He is put on life support but dies 5 days later. At autopsy, there is an area of necrosis and microscopically these lesions are noted to have increased numbers of cells distributed around the central zone of necrosis. Which of the following cell types is most likely to have a phagocytic function in these lesions?
Microglial cells are part of the body's fixed macrophage system, derived originally from mesoderm. Microglia can respond to cerebral injuries by taking on a macrophage-like function. The arachnoid layer is part of the meninges covering the brain. Astrocytes can proliferate in response to brain injuries, a process called gliosis, but there is no phagocytosis. Ependymal cells line the ventricular system containing CSF. Oligodendroglial cells provide the myelin sheaths for neuronal axons in the CNS.
Arachnoidal cells
Astrocytes
Ependymal cells
Microglia
Central Nervous System