Answer
The term for organs or cells that are influenced by a given hormone is "target cells" or "target organs." These cells or organs possess specific receptors that are designed to bind with the particular hormone. These receptors are often located on the surface of the cell or within the cell, depending on the nature of the hormone and how it functions.
The reason why only target cells or organs respond to a given hormone, even though the hormone travels throughout the body via the bloodstream, is due to the specificity of the hormone-receptor interaction. This specificity is similar to a lock-and-key mechanism: a hormone acts as the "key," and its corresponding receptor on the target cell acts as the "lock." Only cells that possess the specific receptor for a particular hormone will be able to respond to that hormone's signal.
Factors contributing to this specificity include:
1. **Receptor Specificity:** Each hormone is structurally unique and fits only a specific type of receptor. Other cells without the appropriate receptor won't recognize or interact with the hormone.
2. **Concentration of Receptors:** Target cells that are meant to respond to a particular hormone usually have a higher density of the corresponding receptors, making them more sensitive to that hormone's presence.
3. **Cell Signaling Pathways:** When a hormone binds to its receptor on a target cell, it initiates a series of biochemical events (cell signaling pathways) within the cell. These pathways are specific to each hormone-receptor interaction and lead to the cellular response that the hormone is intended to trigger.
4. **Downregulation and Desensitization:** Over time, cells might regulate their receptor density in response to prolonged exposure to a hormone. This can lead to downregulation of receptors, making the cell less responsive to the hormone.
In essence, the specificity of hormone-receptor interactions ensures that only the appropriate cells or organs respond to a given hormone, preventing widespread and indiscriminate effects on all cells in the body. This targeted response is essential for maintaining precise control over physiological processes and avoiding potential disturbances in homeostasis.
Work Step by Step
The term for organs or cells that are influenced by a given hormone is "target cells" or "target organs." These cells or organs possess specific receptors that are designed to bind with the particular hormone. These receptors are often located on the surface of the cell or within the cell, depending on the nature of the hormone and how it functions.
The reason why only target cells or organs respond to a given hormone, even though the hormone travels throughout the body via the bloodstream, is due to the specificity of the hormone-receptor interaction. This specificity is similar to a lock-and-key mechanism: a hormone acts as the "key," and its corresponding receptor on the target cell acts as the "lock." Only cells that possess the specific receptor for a particular hormone will be able to respond to that hormone's signal.
Factors contributing to this specificity include:
1. **Receptor Specificity:** Each hormone is structurally unique and fits only a specific type of receptor. Other cells without the appropriate receptor won't recognize or interact with the hormone.
2. **Concentration of Receptors:** Target cells that are meant to respond to a particular hormone usually have a higher density of the corresponding receptors, making them more sensitive to that hormone's presence.
3. **Cell Signaling Pathways:** When a hormone binds to its receptor on a target cell, it initiates a series of biochemical events (cell signaling pathways) within the cell. These pathways are specific to each hormone-receptor interaction and lead to the cellular response that the hormone is intended to trigger.
4. **Downregulation and Desensitization:** Over time, cells might regulate their receptor density in response to prolonged exposure to a hormone. This can lead to downregulation of receptors, making the cell less responsive to the hormone.
In essence, the specificity of hormone-receptor interactions ensures that only the appropriate cells or organs respond to a given hormone, preventing widespread and indiscriminate effects on all cells in the body. This targeted response is essential for maintaining precise control over physiological processes and avoiding potential disturbances in homeostasis.
