Learners examine the structure and function of skin including the production of melanin.

Students read about foods that are high in nutrients compared to the number of calories. They identify if certain foods have high or low nutrient density.

In this interactive object, learners review the medication, nursing implications, and client outcomes of gastrointestinal management. For every right answer, the learner earns a square on a tic-tac-toe board while playing against the computer or another contestant.

In this interactive object, learners read about the seven hormones that help regulate blood glucose. A quiz completes the activity.

In this animated object, learners view hydrogen and hydroxide ions in a solution. A brief quiz on the basic principles of the term pH completes the activity.

This learning object shows how the shape of a stain defines the angle of impact. In general terms the more circular the stain, the more perpendicular will be the angle at which it struck the surface. The more elliptical the shape of the stain, the more acute the angle will be. With practice and experience, the analyst can recognize the general angle of impact based solely on the shape of the stain.

Students read about how acid/base balance affects a person's health. This activity includes animation.

In this interactive object, the learner matches various disorders to the acid-base disturbances they cause.

Through the use of symbols and words, the learner reviews the etiologies, symptoms, and treatment of respiratory and metabolic acid-base disturbances.