As you are learning, your body and the bodies of all organisms are highly complex, comprised of many different types of cells, each with a vital function that is required for the body’s survival. There are mechanisms that act like lines of communication, allowing different cells to communicate. Messenger molecules serve to coordinate signals between cells and between organs and are described as having autocrine (internal), paracrine (local) or endocrine (system-wide) functions.  Without these messenger molecules, how else does your liver know when to produce important proteins for homeostasis?  How does your heart know when to beat faster and then slow down?  How do your lungs know when to breathe faster?  The communications between your brain and organs, and between the different organs must be tightly regulated and controlled.

For this discussion board, select two types of messengers that our body uses to communicate between organs or between different cell types. 

  • Describe the messengers.
  • Discuss where the messengers are made and what is their function.
  • Are the messengers part of an autocrine, paracrine or endocrine pathway? 
  • What would happen if the messengers you have selected were inactive?