Question

What respiratory structure controls breathing?

a. Trachea
b. Lungs
c. Diaphragm
d. Bronchi

Answer 1

The diaphragm is the muscle that controls breathing by contracting and relaxing to modulate the volume of the chest cavity. The correct option is c.

Step-by-step explanation:

The diaphragm is a sheet of muscle that is located below the lungs. When it contracts, it lowers, and the chest cavity enlarges, causing air to be drawn into the lungs. During exhalation, the diaphragm relaxes, and air is expelled from the lungs as the chest cavity decreases in size. This muscle works involuntarily under the control of the respiratory center in the brain.

In terms of the order of airflow during inhalation, the correct sequence is: nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, and finally reaching the alveoli. The structure of the lungs and thoracic cavity, including the intercostal muscles and the diaphragm, control the mechanics of breathing. The exchange of gases, where oxygen is taken into the blood and carbon dioxide is released from the blood into the alveoli, occurs in these tiny air sacs.

Hence, c is the correct option.

Answer 2

The diaphragm is the respiratory structure that controls breathing by contracting and relaxing to facilitate air movement in and out of the lungs.

So, the correct answer is C.

Step-by-step explanation:

The respiratory structure that controls breathing is the diaphragm. This sheet of muscle spreads across the bottom of the rib cage, and operates involuntarily during the process of breathing. Upon inhalation, the diaphragm contracts and moves downward, increasing the volume of the thoracic cavity, and allowing air to be drawn into the lungs. Conversely, when exhaling, the diaphragm relaxes and moves upwards, decreasing the thoracic cavity's volume and expelling air from the lungs.

It is worth mentioning that, during the journey of air, it passes through the nasal cavity, pharynx (throat), larynx (voice box), trachea (windpipe), bronchi, bronchioles, and finally reaches the alveoli where gas exchange occurs. Each of these structures plays a role in the breathing process, but the diaphragm specifically controls the mechanical aspect of inhalation and exhalation.

So, the correct answer is C.Diaphragm