Answer to Question 1
Answer: B
Answer to Question 2
Answer: No one area is the final controller of eating. Sensory and motor information from the
gut is sent to the brainstem, where basic feeding reflexes are controlled. Forebrain circuits arising from the lateral hypothalamus can act via MCH and orexins to facilitate eating, and this region appears to be sensitive to the orexigenic effects of NPY. Cells within the arcuate nucleus secrete both NPY as well as agouti-related peptide (AGRP), which acts as an antagonist at MC4- receptors that normally function to inhibit eating. Thus NPY and AGRP stimulate eating. A common finding is that a specific neuropeptide may exert dual actions; namely, facilitating actions in one pathway (e.g., MCH/orexin) and inhibiting activity in the other pathway (e.g., NPY/AGRP). Leptin can inhibit NPY activity and can activate cells that express CART.