Answer
Autocrine: cell releases signal that binds to its own receptors
Juxtacrine: requires close contact between signal releaser and receiver.
Paracrine: cell releases signal that targets adjacent cells that aren't attached by gap junctions
Hormones: signals secreted into the bloodstream to target cells on other parts of the body.
Work Step by Step
Autocrine: cell releases signal that binds to its own receptors
Juxtacrine: requires close contact between signal releaser and receiver.
Paracrine: cell releases signal that targets adjacent cells that aren't attached by gap junctions
Hormones: signals secreted into the bloodstream to target cells on other parts of the body.