Snake venom is produced in modified parotid glands normally responsible for secreting saliva. The normal glands respond by secreting parathyroid hormone at a persistently high rate. There are eight different types of secreting glands. Below this are a number of small glands secreting components of the seminal fluid. These groups share an oral gland capable of secreting toxins (a derived trait). Pheochromocytoma is a disease in which a catecholamine secreting tumor develops. Females attract males by secreting pheromones from their skin. She ceases to feed and stops secreting stomach acid. Elaiophores are similar to nectaries but are oil secreting. Defence is typically achieved by secreting antifeedant chemicals into the woody cell walls.