sustentacular

Sustentacular is an anatomical term derived from Latin sustinere, meaning to sustain or support. In histology, it describes cells or tissues that provide structural and metabolic support to more specialized cells. The term is used most commonly for sustentacular cells of the olfactory epithelium and for the Müller glial cells in the retina, and it is also applied to Sertoli cells inside the seminiferous tubules of the testis, which are sometimes called sustentacular or nurse cells.

In the olfactory epithelium, sustentacular cells are tall, columnar supporting cells that physically enwrap the olfactory receptor neurons. They contribute to barrier function through tight junctions, participate in detoxification of odorants, and help maintain the ionic and metabolic milieu necessary for olfactory signaling. They also engage in phagocytosis of degenerating cells as part of epithelial turnover.

In the retina, sustentacular cells commonly refer to Müller glial cells, the principal supporting glia. Müller cells span the thickness of the retina and help regulate extracellular ion balance, recycle neurotransmitters, provide metabolic support to neurons, and contribute to retinal homeostasis and the blood-retina barrier.

In the testis, Sertoli cells are sometimes described as sustentacular cells. They organize and nourish developing germ cells within the seminiferous tubules, form the blood-testis barrier, secrete nutrients and growth factors, and respond to follicle-stimulating hormone and testosterone to regulate spermatogenesis.

Together, sustentacular describes cells or structures whose primary role is to support neighboring parenchymal cells and maintain tissue integrity.