How do endocrine hormones reach their target cells?

• A. They are released into synaptic clefts and act on adjacent neurons.
• B. They are secreted into the bloodstream and travel to target cells throughout the body.
• C. They diffuse directly through gap junctions to neighboring cells.
• D. They are transported through ducts to specific organs.

Answer: (B)

Verified step by step guidance

1. Understand the role of endocrine hormones: Endocrine hormones are chemical messengers secreted by endocrine glands to regulate various physiological processes in the body.
2. Recognize the transport mechanism: Endocrine hormones are secreted directly into the bloodstream, which serves as the transport medium to carry these hormones to their target cells.
3. Identify the target cells: Target cells are specific cells that have receptors for the hormone. These receptors allow the hormone to bind and initiate a response.
4. Differentiate endocrine signaling from other types: Unlike synaptic signaling (neurotransmitters acting on adjacent neurons), gap junction signaling (direct cell-to-cell communication), or duct-based transport (exocrine glands), endocrine hormones rely on the circulatory system for widespread distribution.
5. Conclude the process: Once the hormone reaches the target cell via the bloodstream, it binds to its specific receptor, triggering a cascade of cellular responses to achieve the intended physiological effect.