Humans are unique among the earth’s life forms in their ability to think, imagine, create, evaluate, learn and apply what they learnt to improve their quality of life by adapting well to the environment they live in. So it is interesting to know about ourselves, our body and our relationship with everything around us.

The human body is a complex system which integrates different organ systems which perform specialized functions. At one end of the spectrum, it includes the study of individual molecules—for example, how a particular protein’s shape and electrical properties allow it to function as a channel for ions to move into or out of a cell.

At the other end, it is concerned with complex processes that depend on the integrated functions of many organs in the body—for example, how the heart, kidneys and several glands all work together to cause the excretion of more sodium in the urine when a person has eaten salty food.