Endocrine system observed in all animals with a nervous system and all vertebrates have an hypothalamus-pituitary axis. All vertebrates have a thyroid, which in amphibians is also crucial for transformation of larvae into adult form. All vertebrates have adrenal gland tissue, with mammals unique in having it organized into layers. All vertebrates have some form of a renin–angiotensin axis, and all tetrapods have aldosterone as a primary mineralocorticoid. Endocrine system The endocrine system is a chemical messenger system consisting of hormones, the group of glands of an organism that secrete those hormones directly into the circulatory system to regulate the function of
Labial glands the superior cervical ganglion and pass through the otic ganglion without synapsing. Labial glands The labial glands are minor salivary glands situated between the mucous membrane and the orbicularis oris around the orifice of the mouth. They are circular in form, and about the size of small peas; their ducts open by minute orifices upon the mucous membrane. Like the parotid and buccal glands, the labial glands are innervated by parasympathetic fibres that arise in the inferior salivatory nucleus, travel with the glossopharyngeal nerve and lesser petrosal nerve to the otic ganglion, where they synapse and then continue to the