In a homeostatic control mechanism that regulates respiration, what acts as the effector(s) in this system?

• A. Chemoreceptors in the carotid and aortic bodies
• B. Alveolar epithelial cells
• C. Respiratory muscles such as the diaphragm and intercostal muscles
• D. Medullary respiratory centers in the brainstem

Answer: (C)

Verified step by step guidance

1. Step 1: Understand the concept of a homeostatic control mechanism. Homeostasis refers to the maintenance of a stable internal environment in the body. A control mechanism typically involves three components: a receptor (detects changes), a control center (processes the information and decides on a response), and an effector (carries out the response).
2. Step 2: Identify the role of chemoreceptors in the carotid and aortic bodies. These act as receptors in the system, detecting changes in blood oxygen, carbon dioxide, and pH levels. They send signals to the control center when deviations from normal levels occur.
3. Step 3: Examine the role of the medullary respiratory centers in the brainstem. These centers act as the control center in the homeostatic mechanism. They process the information received from the chemoreceptors and determine the appropriate response to restore balance.
4. Step 4: Determine the role of respiratory muscles such as the diaphragm and intercostal muscles. These muscles act as the effectors in the system. They execute the response by adjusting the rate and depth of breathing to regulate oxygen and carbon dioxide levels in the blood.
5. Step 5: Recognize that alveolar epithelial cells are not directly involved as effectors in this homeostatic mechanism. Their primary role is in gas exchange within the lungs, not in the regulation of respiration.