Patient Care Technician (PCT) AAH Practice Exam

Metabolism refers to the intricate set of life-sustaining chemical and physical changes that occur within the body. It encompasses all the biochemical reactions that convert food into energy, help in the synthesis of necessary compounds, and facilitate the breakdown of substances for use or excretion. This definition captures the entirety of metabolic processes, including catabolism (the breakdown of substances for energy) and anabolism (the building of complex molecules from simpler ones).

Understanding metabolism is crucial in patient care as it relates directly to how the body utilizes nutrients, manages energy levels, and how drugs and medications are processed. This knowledge provides insights into a patient's nutritional needs and the potential impact of medications on their metabolic state.

The other options represent different physiological functions but do not encapsulate the broad scope of metabolic processes. For instance, the rate at which the heart beats pertains to cardiovascular function, gas exchange in the lungs relates to respiratory physiology, and nutrient delivery through the bloodstream is a component of metabolism but does not define it. Thus, defining metabolism as the process of chemical and physical change comprehensively covers the various metabolic activities within the human body.