The chapter features discussion and multiple-choice questions on human physiology. The topics that are briefly covered in this chapter include structure of the cell, blood, digestive system, renal physiology, cardiovascular system, and respiratory system. Cell is defined as the structural and functional unit of the living body. Tissue is defined as the group of cells having similar function. An organ is defined as the structure that is formed by two or more primary types of tissues, which execute the functions of the organ. The organ system is defined as group of organs that work together to carry out specific functions of the body. Blood is a connective tissue in fluid form. It is considered as the ‘fluid of life’ because it carries oxygen from lungs to all parts of the body and carbon dioxide from all parts of the body to the lungs. Digestive process is accomplished by mechanical and enzymatic breakdown of food into simpler chemical compounds. Respiration is the process by which oxygen is taken in and carbon dioxide is given out.