Final answer:
The body systems involved in the digestion process are primarily the digestive, nervous, cardiovascular, and muscular systems. These systems work together to ensure the efficient breakdown, absorption, and transport of nutrients.
Step-by-step explanation:
The given diagram likely illustrates the interactions between different body systems during the digestion process. This process involves multiple organ systems, including the digestive system itself, which is primarily responsible for the breakdown and absorption of nutrients. Additionally, the nervous system plays a role in regulating digestive activities through signaling mechanisms, while the cardiovascular system supports the digestive process by delivering oxygen and nutrients to the digestive organs and carrying away absorbed substances. The muscular system contributes through the movement and mixing of food in the digestive tract.