The term that is used for the pressure of each gas in a mixture of gases is:

A. The hilum is the region on the medial side of the lung where the bronchus, blood vessels, and nerves enter and exit the lung.
B. The epiglottis is a flap of tissue that covers the trachea during swallowing to prevent food from entering the airways, but it is not related to the entry of structures into the lung.
C. The nares are the nostrils through which air enters the respiratory system, not the area where the bronchus and vessels enter the lung.
D. The conchae (also known as turbinates) are structures inside the nasal cavity that help warm and humidify air, not related to the lung’s entry point.

A. The cerebellum is involved in coordinating movement and balance but is not primarily responsible for regulating respiration.
B. The diencephalon is involved in sensory processing and regulation of autonomic functions but does not directly control respiration.
C. The cerebral cortex is involved in voluntary control over breathing (such as when you hold your breath), but the central regulation of breathing is managed by the brainstem.
D. The brainstem (specifically the medulla oblongata and pons) is the primary control center for respiration. It regulates the rate and depth of breathing by responding to levels of oxygen and carbon dioxide in the blood.