Read the passage and answer the question.

(1) The human body is made of trillions of cells. Cells are the basic unit of all living things. Each cell is surrounded by the cell membrane. This membrane holds the cell together and controls what goes into and out of the cell. The nucleus is the control center of the cell and contains the DNA. The cytoplasm is the jellylike fluid outside of the nucleus where other parts or organelles of the cell are located. Each type of cell performs a specific job. For example, red blood cells carry oxygen to all parts of the body while the white blood cells work to fight infections. Groups of cells that work together are called tissue.

(2) There are four types of tissues that are formed as cells join together and function as a group. Each type of tissue has a distinctive structure and performs a specific job. Muscle tissue is made up of long and narrow muscle cells. Muscle tissue makes your body parts move by contracting and relaxing. Connective tissue is what holds up your body and connects its parts together. The bone is made up of connective tissue. Nerve tissue is made up of long nerve cells that branch through your body and carry messages throughout the body. Epithelial tissue is made of wide, flat epithelial cells. This tissue lines the surfaces inside the body and forms the outer layer of the skin. Groups of tissue join together to form the organs in our body such as the heart, liver, lungs, brain, and kidneys just to name a few. Subsequently these organs work together to form our body systems. Each system works in complete coordination with one another, as well as with the other systems of the body.

(3) The nervous system is made up of the brain, the spinal cord, and thousands of nerves. The brain controls the nervous system. The spinal cord is the link between the brain and other parts of the body. It sends and receives the messages from the brain and the nerves. The nerves are bundles of fibers that carry the messages throughout the body.

(4) The digestive system is made up of the esophagus, stomach, liver, gallbladder, pancreas, large and small intestines, appendix, and rectum. Digestion actually begins in the mouth when food is chewed and mixed with saliva. Muscles in the esophagus push food into the stomach where it mixes with digestive juices. While in the stomach, food is broken down into nutrients and turns into a thick liquid. The food then moves into the small intestine where more digestive juices complete the breaking down of the food. It is in the small intestines that nutrients are absorbed into the blood and carried throughout the body. The leftover material that is unusable by the body moves into the large intestines where the body absorbs the water that is contained before passing from the body through the rectum.

What would be an appropriate illustration or diagram to include with the information in Section 2 of the above passage?