The endocrine system in mammals works hand in hand with the nervous system to coordinate everything from when you feel hungry to the digestion of food to the drive to find a mate. While the nervous systems uses electrical impulses to send messages at lightening fast rates, the endocrine uses hormones to send signals that are relatively slower but longer lasting.

Detailed annotated images of the endocrine system in a California Sea Lion are shown below.  CLICK on an image to see an enlarged view.