Local vs. Long-Distance Cell Communication

1. What They Are:

   • Local Communication: This is when small molecules send messages to nearby cells. An example is paracrine signaling.
   • Long-Distance Communication: This happens when hormones travel through the blood to reach cells that are far away. This is called endocrine signaling.

2. How Far They Go:

   • Local signals usually only reach cells that are about 100 micrometers away.
   • Long-distance signals can reach cells that are 1 meter away or even more in bigger animals.

3. How Fast They Work:

   • Local communication is quick. It usually happens in milliseconds to seconds.
   • Long-distance communication is slower. It might take minutes or even hours.

4. Some Examples:

   • For local communication, think of neurotransmitters.
   • For long-distance communication, insulin is a good example. It comes from the pancreas and goes into the bloodstream.