The endocrine system is responsible for:

Correct Answer: B

Rationale: The endocrine system secretes hormones to regulate processes like metabolism and growth. Distinct from circulatory or nervous roles, it's a chemical messenger network. Nurses monitor it like in diabetes ensuring hormonal balance maintains bodily harmony.

Correct Answer: D

Rationale: The humerus spans the upper arm, linking shoulder to elbow, supporting movement. Unlike leg or forearm bones, it's the arm's structural anchor. Clinicians focus here for fractures, ensuring its integrity restores arm function.

Correct Answer: B

Rationale: Villi amplify the small intestine's absorptive surface, capturing nutrients efficiently. Unlike lung or hair structures, they're digestive specialists. Clinicians address them in malabsorption like celiac disease ensuring nutrition fuels the body.

Correct Answer: D

Rationale: Anatomy studies both the structure of body parts and their relationships, distinguishing it from physiology, which focuses on function. Option D (A and B only) is correct as it encompasses both aspects. For example, anatomy examines the femur's shape and its articulation with the pelvis, not how it moves (physiology). This dual focus helps understand bodily organization, crucial for medical fields like surgery, where structural knowledge guides intervention.

Correct Answer: B

Rationale: The correct order is atom (smallest), molecule, organelle, cell, tissue, organ, organ system, organism (most complex). B aligns with this, starting with atoms forming molecules (e.g., water), then organelles (e.g., ribosomes), cells, tissues (e.g., muscle), organs (e.g., heart), systems (e.g., circulatory), and organisms (e.g., human). Other options misplace levels, disrupting anatomy's logical progression.