Physiology the study of how the body functions. Anatomy a branch of biology that is the consideration of the structure of living things. Anatomical position frame of reference for anatomical description and dissection. Inferior away from the head, lower, below. Superior towards the head, upper, above. Proximal nearer trunk or point of origin, center. Distal away from trunk or point of origin. Medial towards midline of the body. Lateral away from midline of the body. Anterior/ventral towards front of the body. Posterior/dorsal towards back of the body. Deep beneath or below the surface. Atoms: oxygen, carbon, hydrogen and nitrogen = 96% of the body. Molecules: proteins, fats, cho and nucleic acids. Physiology typically starts at this level because of proteins. Cells are the basic unit of structure and function in the body. The smallest unit capable of carrying out the processes associated with life. The body is made up of many types of cells, each with a specialized function.