Problem 104 - Objective Biology for NEET

Question

Receptors associated with aortic and carotid artery can recognize changes in and concentration and send necessary signal to for remedial action. (a) \(\mathrm{O}_{2}, \mathrm{CO}_{2}\), pneumotaxic (b) \(\mathrm{CO}_{2}, \mathrm{H}^{+}\), rhythm centre (c) \(\mathrm{CO}_{2}, \mathrm{H}^{+}\), apneustic centre (d) \(\mathrm{O}_{2}, \mathrm{H}^{+}\), pneumotaxic

Step-by-Step Solution

Answer

The correct answer is option (b): \(\mathrm{CO}_{2}, \(\mathrm{H}^{+}\), rhythm centre.

Step 1: Review the Function of Aortic and Carotid Receptors

These are chemoreceptors, primarily sensitive to the levels of \(\mathrm{CO}_{2}\) and \(\mathrm{H}^{+}\) ions in the blood.

Step 2: Review the Remedial Centers

The chemoreceptors send signal to the rhythm center for necessary adjustments when they sense changes.

Step 3: Choose the Correct Option

Given this information, the receptors associated with aortic and carotid artery can recognize changes in \(\mathrm{CO}_{2}\) and \(\mathrm{H}^{+}\) concentration and send necessary signal to rhythm centre for remedial action. Hence, the correct answer must be option (b).

Key Concepts

Aortic Receptors

The aortic receptors are specialized chemoreceptors located at the arch of the aorta. Their primary role is to detect changes in blood chemistry.
The aortic receptors closely monitor concentrations of carbon dioxide (CO\(_2\)) and hydrogen ions (H\(^+\)) in the blood. Stepping in when these levels rise, they help maintain balanced pH levels.

• Sensitive to blood gas levels
• Located strategically at the aortic arch
• Integral to maintaining homeostasis

Any imbalance, such as an increase in CO\(_2\), prompts these receptors to signal the brain, triggering adjustments to restore equilibrium.

Carotid Receptors

Carotid receptors are located in the carotid arteries, which are key vessels in the neck that supply blood to the brain. Like the aortic receptors, carotid receptors are chemoreceptors that detect changes in

• Carbon dioxide (CO\(_2\))
• Hydrogen ions (H\(^+\))

They are incredibly sensitive to the changes in the levels of these components. When the concentration of CO\(_2\) or H\(^+\) increases, they alert the respiratory centers to adjust the breathing rate.
By ensuring the proper balance of gases, these receptors play a crucial role in maintaining brain oxygenation and overall bodily function.

Respiratory Regulation

Respiratory regulation is a finely tuned process overseen by various centers in the brain. It ensures that breathing rates correspond to the body's needs. The rhythm center, located in the medulla oblongata, plays a pivotal role in this regulation. Signals from chemoreceptors, like those in the aorta and carotid arteries, guide the rhythm center.
- Adjusts breathing rate to balance gas concentrations- Maintains stable internal environments across different conditions
When CO\(_2\) levels in the blood rise, the rhythm center instructs the respiratory muscles to increase the rate and depth of breathing, enhancing oxygen intake and carbon dioxide expulsion.

Carbon Dioxide Detection

The detection of carbon dioxide is a critical function of both aortic and carotid receptors. Carbon dioxide, a byproduct of cellular metabolism, dissolves in the blood and affects its acidity. When CO\(_2\) levels rise, chemoreceptors trigger responses to mitigate this increase.

• Increased CO\(_2\) leads to elevated acidity (more H\(^+\))
• Chemoreceptors detect these changes efficiently
• Promptly signal remedial breathing adjustments

This feedback loop ensures the maintenance of physiological balance by prompting adjustments in respiratory rate, aligning it with metabolic demands.