Question

In humans, the respiratory center a. is stimulated by carbon dioxide. b. is located in the medulla oblongata. c. controls the rate of breathing. d. All of these are correct.

Short answer

The respiratory center in humans is stimulated by carbon dioxide, located in the medulla oblongata, and controls the rate of breathing. Therefore, all the given statements are correct. The correct answer is d. All of these are correct.

Step-by-step solution

Statement a: Is stimulated by carbon dioxide.

The respiratory center in humans is indeed stimulated by carbon dioxide. When carbon dioxide levels in the blood increase, the respiratory center sends signals to the muscles involved in breathing, such as the diaphragm, to increase the rate of respiration. This helps in expelling excess carbon dioxide from the body.

Statement b: Is located in the medulla oblongata.

The respiratory center is located in the medulla oblongata, a part of the brainstem. The medulla oblongata is responsible for regulating various autonomic functions, including respiration.

Statement c: Controls the rate of breathing.

The respiratory center does control the rate of breathing. By responding to changes in the levels of carbon dioxide and oxygen in the blood, as well as other factors such as physical activity, the respiratory center adjusts the rate and depth of breathing to maintain optimal levels of these gases in the body.

Statement d: All of these are correct.

Considering the analysis of each statement provided above, we can conclude that all of them are correct. The respiratory center is stimulated by carbon dioxide, is located in the medulla oblongata, and controls the rate of breathing. So, the correct answer is: d. All of these are correct.

Key concepts

carbon dioxide regulation

The human body has an important mechanism to keep its internal environment stable, called carbon dioxide regulation. When cells in our body produce energy, they release carbon dioxide as a waste product. The accumulation of too much carbon dioxide can be harmful, so the body must manage its levels carefully.

The respiratory center located in the brain detects changes in carbon dioxide levels in the blood. It is highly sensitive to even small fluctuations.

• When carbon dioxide levels rise, the respiratory center is triggered.
• This results in an increased breathing rate to remove the excess gas.
• Conversely, if levels drop, breathing slows down to conserve carbon dioxide.

This seamless balancing act ensures that the blood pH remains stable, maintaining homeostasis in the body.

medulla oblongata

An essential part of the brainstem is the medulla oblongata. It is where the respiratory center is located. The medulla oblongata carries out several critical functions by regulating autonomic activities such as heart rate, blood pressure, and breathing.

Being part of the central nervous system, it serves as the hub for controlling the involuntary processes of the body. It has built-in sensors that detect changes in the concentration of gases, particularly oxygen and carbon dioxide. When these sensors detect imbalances:

• The medulla sends nerve signals to adjust lung function.
• This helps in increasing or decreasing breathing as needed.

In this way, the medulla oblongata ensures that essential bodily functions operate smoothly without conscious effort.

breathing rate control

The control of breathing rate is a finely tuned process that our bodies automatically perform. This process optimizes how we receive oxygen and remove carbon dioxide from our bodies.

The breathing rate varies based on several factors:

• Levels of carbon dioxide and oxygen in the blood prompt immediate adjustments.
• Physical activity increases demand for oxygen, causing the rate to accelerate.
• Factors like emotional stress or temperature changes can also influence the rate.

The respiratory center, particularly in the medulla oblongata, is responsible for managing these adjustments. By continuously monitoring internal and external changes, it maintains a sustainable breathing pattern. This ensures that our cells receive enough oxygen to function while keeping carbon dioxide at safe levels.