Quick Facts
The vascular process of astrocytes is a pyramidal expansion of a process of an astrocyte against the wall of a capillary in the central nervous system (Dorland, 2011).
Related parts of the anatomy
Structure and/or Key Features
Astrocytes exhibit multiple radiating processes with bulbous ends which are known as astrocytic end feet. The bulbous ends of the astrocytic end feet extend from the astrocyte cell body and cling to neurons and capillaries, specifically on the basement membrane that surrounds the endothelial cells and pericytes (Marieb, Wilhelm and Mallatt, 2012).
Function
Astrocytic end feet extend and attach to the nodes of Ranvier and synapses and so cover these bare areas where a myelin sheath is absent.
The astrocytic end feet surround endothelial cells and, along with the tight junctions between endothelial cells and the basal lamina, form the blood-brain-barrier (Ross and Pawlina, 2006).
The astrocytic end feet form the glia limitans, a relatively impermeable barrier that surrounds the central nervous system (Ross and Pawlina, 2006).
References
Dorland, W. (2011) Dorland's Illustrated Medical Dictionary. 32nd edn. Philadelphia, USA: Elsevier Saunders.
Marieb, E. N., Wilhelm, P. B. and Mallatt, J. (2012) Human Anatomy. fifth edn.: Benjamin Cummings.
Ross, M. H. and Pawlina, W. (2006) Histology: A text and atlas. Lippincott Williams & Wilkins.
