The International Union for the Conservation of Nature (IUCN) lists 9 species of spider monkey, which can be found in rain forests from southern Mexico through Brazil. The IUCN lists 3 spider-monkey species as Critically Endangered; 5 species of spider monkey are listed as Endangered, and 1 species is Vulnerable.
The foundations of the endocrine system are hormones and glands. A gland is a group of cells that produces and secretes hormones. Hormones are the body's chemical messengers. They send and relay messages between different systems. Many different hormones move through the bloodstream.
The Endocrine system (along with the nervous system) controls and regulates the complex activities of the body. The Endocrine system regulates the activities of the body by secreting complex chemical substances (hormones) into the blood stream.These secretions come from a variety of glands which control various organs of the body. The key functions are: 1  To regulate the metabolic functions of the body.he Endocrine system (along with the nervous system) controls and regulates the complex activities of the body. The Endocrine system regulates the activities of the body by secreting complex chemical substances (hormones) into the blood stream.