Which type of signaling is exemplified when the hormone ADH (antidiuretic hormone) travels through the bloodstream to affect target cells in the kidneys?

• A. Paracrine signaling
• B. Endocrine signaling
• C. Synaptic signaling
• D. Autocrine signaling

Answer: (B)

Verified step by step guidance

1. Understand the different types of cell signaling: Endocrine signaling involves hormones traveling through the bloodstream to distant target cells. Paracrine signaling affects nearby cells. Synaptic signaling occurs between neurons via neurotransmitters. Autocrine signaling involves a cell targeting itself.
2. Identify the key details in the problem: The hormone ADH (antidiuretic hormone) is mentioned as traveling through the bloodstream to affect target cells in the kidneys.
3. Match the description to the correct signaling type: Since ADH travels through the bloodstream to reach distant target cells, this aligns with the definition of endocrine signaling.
4. Eliminate incorrect options: Paracrine signaling is incorrect because it involves nearby cells. Synaptic signaling is incorrect because it involves neurons and neurotransmitters. Autocrine signaling is incorrect because it involves a cell signaling itself.
5. Conclude that the correct type of signaling for this scenario is endocrine signaling, as it matches the description provided in the problem.