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 nervous system is responsible for coordinating and controlling entire functions of the body. It handles all the activities of the body and is responsible for various senses humans feel. The... The nervous system is responsible for coordinating and controlling entire functions of the body. It handles all the activities of the body and is responsible for various senses humans feel. The nervous system is a highly specialized network system that contains countless neurons, which transmit signals between different parts of the body.