In neuroendocrine signaling, neurosecretory cells secrete neurohormones that travel through the blood to affect target cells. In a form of paracrine signaling, called autocrine signaling, hormones secreted into the extracellular fluid affect the cell that secreted them.Īnother type of signaling, synaptic signaling, involves the release of neurotransmitters from neuron terminals into the synapse-a specialized junction that relays information between neurons-where they bind to receptors on neighboring neurons, muscle cells, and glands. Paracrine signaling sends hormones out of the endocrine cell and into the extracellular fluid where they affect local cells. While most hormones travel through the circulatory system to reach their target cells, there are also alternate routes to bring hormones to target cells.
Eventually, they diffuse out of the blood and bind to target cells which have specialized receptors to recognize the hormones. These signals are produced in endocrine cells, secreted into the extracellular fluid, and then diffuse into the blood. The endocrine system sends hormones-chemical signals-through the bloodstream to target cells-the cells the hormones selectively affect.
