Target cells

Definition

Target cells are specific cells within the body that have receptors for particular hormones or signaling molecules, allowing them to respond to those signals. These cells play a crucial role in the endocrine system by facilitating communication between different parts of the body through hormonal signaling. When a hormone binds to its receptor on a target cell, it triggers a response that can influence various physiological processes.

5 Must Know Facts For Your Next Test

1. Target cells have specific receptors for hormones, ensuring that only those cells respond to particular hormonal signals.
2. The interaction between a hormone and its target cell can lead to a range of responses, including changes in metabolism, growth, and mood.
3. Target cells can vary widely depending on the hormone; for example, insulin targets liver and muscle cells to regulate glucose levels.
4. The number of receptors on target cells can change over time, which can influence how sensitive a cell is to a particular hormone.
5. Dysfunction in target cell responses can lead to various health issues, such as insulin resistance in diabetes.

Review Questions

• How do target cells ensure specificity in hormonal responses?
  • Target cells ensure specificity in hormonal responses through the presence of unique receptors that only bind to certain hormones. This means that even though hormones circulate throughout the body, only those target cells with matching receptors will react to a specific hormone. This selectivity is crucial for maintaining proper physiological balance and ensuring that each hormone can effectively elicit its intended response in the correct tissues.
• What role do target cells play in the feedback mechanisms of the endocrine system?
  • Target cells are essential for feedback mechanisms within the endocrine system because they provide the necessary responses to hormones that regulate hormone production. For example, when a hormone binds to its target cell and produces an effect, this can send signals back to the endocrine gland to either increase or decrease hormone production. This feedback loop helps maintain homeostasis and ensures that hormone levels remain within optimal ranges based on the body's needs.
• Evaluate the impact of receptor number changes on target cell sensitivity and overall hormone effectiveness.
  • Changes in the number of receptors on target cells can significantly impact their sensitivity to hormones, affecting overall hormone effectiveness. For instance, if target cells reduce their receptor count due to prolonged exposure to high hormone levels—a process known as downregulation—these cells become less responsive, potentially leading to conditions like insulin resistance. Conversely, if receptor numbers increase through upregulation, target cells may become more sensitive, enhancing their response to circulating hormones. This dynamic regulation is crucial for adapting to varying physiological demands and maintaining hormonal balance.

Related terms

Hormones: Chemical messengers produced by glands in the endocrine system that travel through the bloodstream to target cells, where they elicit specific responses.

Receptors: Proteins located on the surface or inside target cells that bind to specific hormones, allowing the cell to respond to signaling molecules.

Endocrine Glands: Glands that secrete hormones directly into the bloodstream, playing a key role in regulating various physiological functions and processes.