part of part_of adjacent to caecum visceral nucleus A concentration of digestive organs that sometimes includes reproductive organs as well. In cranchiid squids the visceral nucleus is especially distinct: the small, spindle-shaped digestive gland contains the ink sac and is adjacent to the stomach and caecum and associated structures (eg, digestive gland duct appendages, renal appendages). In most cephalopods the concentration of these structures is not so extensive but whenever a concentration exists, a visceral nucleus is present. BTO:0001448 visceral hump anatomical structure digestive system