Where is the central chemoreceptor located?

A. Lysozyme within tears destroy bacteria.: Lysozyme is an enzyme found in tears that helps to break down the cell walls of bacteria, acting as a chemical barrier and part of the innate immune system's first line of defense.

B. Chemotaxis attracts phagocytes to the site where the pathogen invaded.: This is part of the inflammatory response, which occurs after the first line of defense has been breached; therefore, it is not considered a first line of defense action.

C. Natural killer cells are the first lymphocytes to react to infection.: While natural killer cells play an essential role in the immune response, they are part of the second line of defense and respond after pathogens have entered the body.

D. Phagocytes ingest microbes when they enter the body.: This is part of the second line of defense, as phagocytes respond to pathogens that have breached the first line of defense, which includes physical and chemical barriers.

A. Increased surface tension: This would decrease ventilation as it increases the force needed to expand the lungs.

B. Increased lung compliance: Compliance refers to how easily the lungs can expand. Increased compliance makes it easier for the lungs to inflate, thereby increasing ventilation.

C. Fewer alveolar sacs: Having fewer alveolar sacs reduces the surface area for gas exchange, which would likely reduce ventilation efficiency.

D. More airway resistance: Increased airway resistance makes it harder to breathe, so it would reduce ventilation rather than increase it.