suprachiasmatic /ˌsuːpɹəkʌɪəzˈmatɪk/ adjective1 •Situated above the optic chiasm; specifically, designating a nucleus or region in the paraventricular region of the hypothalamus.When I tell you that the suprachiasmatic nucleus is composed of 20,000 brain cells, or neurons, you might assume it is enormous, consuming a vast amount of your cranial space, but actually it is tiny. — 2017
