Lesion of which hypothalamic nuclei leads to loss of circadian rhythm: (A) Dorsomedial, (B) Ventromedial, (C) Supraoptic, (D) Suprachiasmatic
Answer is D. The suprachiasmatic nucleus or nuclei, abbreted SCN, is a tiny region on the brain&;s midline, situated directly above the optic chiasm. It is responsible for controlling circadian rhythms. The neuronal and hormonal activities it generates regulate many different body functions in a 24-hour cycle, using around 20,000 neurons.Ref: Ganong&;s review of medical physiology; 24th edition; page no:-278