Drugs do not metabolize the same way in all people. For what patient would a nurse expect to assess for an alteration in drug metabolism?

A) Proteins:
Proteins are generally too large to diffuse freely across the cell membrane. They require specific transport mechanisms, such as endocytosis or transport proteins, to move in and out of cells. The hydrophilic nature of most proteins further complicates their passage across the lipid bilayer.

B) Enzymes:
Like proteins, enzymes are large molecules that do not freely diffuse across cell membranes. Enzymes, being proteins, also need specialized transport mechanisms or need to be secreted or endocytosed to enter or exit cells.

C) Hormones:
Many hormones, particularly lipid-soluble ones like steroid hormones, can diffuse freely across the cell membrane. These hormones pass through the lipid bilayer due to their hydrophobic nature and bind to intracellular receptors, initiating cellular responses. However, water-soluble hormones (e.g., insulin) typically do not diffuse freely but interact with receptors on the cell surface.

D) Electrolytes:
Electrolytes (such as sodium, potassium, calcium, and chloride ions) are charged particles that cannot pass freely through the lipid bilayer due to the hydrophobic interior of the cell membrane. They require specific ion channels or transporters to move in and out of the cell. Diffusion of electrolytes is facilitated through these channels, but it is not a simple diffusion process as seen with small, uncharged molecules.

A) The patella reflex ("knee jerk") activated by tapping the patella tendon: The patellar reflex is a monosynaptic spinal reflex that involves the somatic nervous system but is a reflex action rather than a voluntary motor function. The somatic nervous system governs voluntary movements, but reflex actions like the patellar reflex are involuntary responses that do not require higher brain input, though they involve somatic motor pathways.

B) Abdominal viscera the beginning of depolarization in the cardiac conduction of impulses: This process is primarily under the control of the autonomic nervous system (ANS), not the somatic nervous system. The ANS regulates involuntary processes like heart rate and digestion, while the somatic nervous system controls voluntary movements and somatic sensation.

C) The act of typing a report using a computer keyboard: Typing is a voluntary motor activity, controlled by the somatic nervous system. The somatic system is responsible for conscious, voluntary actions such as moving muscles in the arms, hands, and fingers to type. This is the most accurate example of a somatic function.

D) Withdrawing the hand after touching a hot surface: This is a reflex action known as the "withdrawal reflex," which involves the somatic nervous system. However, it is an involuntary action triggered by a sensory stimulus. While it does involve the somatic system, it is not a voluntary action like typing, and reflexes are considered part of the automatic response mechanisms.