AP BIOLOGY

Detailed explanation-1: -In endocrine signaling, the signaling molecules (hormones) are secreted by specialized endocrine cells and carried through the circulation to act on target cells at distant body sites.

Detailed explanation-2: -Signals that are produced in one part of the body and travel through the circulation to reach far-away targets are known as hormones.

Detailed explanation-3: -The cell signaling pathways induced by the steroid hormones regulate specific genes on the cell’s DNA. The hormones and receptor complex act as transcription regulators by increasing or decreasing the synthesis of mRNA molecules of specific genes.

Detailed explanation-4: -While paracrine communication is classically mediated through hormones, paracrine communication can also occur through exosomes [81]. Exosomes are small (50–200 nm diameter) extracellular vesicles that are formed intracellularly in endosomes and released when the endosomes fuse with the plasma membrane.

Detailed explanation-5: -Endocrine signaling is an example of long distance communication between hormone producing cells, tissues and glands and cells that express hormone receptor molecules.