Students were first introduced in grade one to the complementary nature of structure and function when they studied the different shapes of animal teeth and inferred the kinds of food those animals eat. Students in grade three studied the external physical characteristics of organisms and considered their functions as a matter of adaptation. Students in grade seven will deepen their understanding of internal structures, a topic that was introduced in grade five.

Anatomists and physiologists consider at different levels the internal structures of living organisms. Mammals have discrete organs, many of which work together as systems. For example, the adrenal and pituitary glands are parts of the endocrine system, and the kidneys and bladder are parts of the excretory system. Flowering plants have tissues, such as xylem and phloem, that are part of a vascular system. Organs themselves may have specific tissues; for example, the white and gray matter of the brain can serve multiple functions. The pancreas produces both digestive enzymes and blood hormones.

Students in grade seven learn about the musculoskeletal system, the basic functions of the reproductive organs of humans, and the structures that help to sustain a developing fetus. Students also study the intricate structures of the eye and ear, which have well-understood functions in sight and hearing. Although many topics are covered in this section, they are all grouped in the fields of anatomy and physiology.