There are a number of organ systems in the body. There are eleven organ system to be exact. By the names of the systems, some of them are quite easy to figure out what parts of the body are included in them.
However, others are not so easy to figure out. These systems include the integumentary system which includes the skin, oil glands, sense receptors, nails, hair and sweat glands. Another one is the skeletal system which includes the frame of the body, plus the bones and joints.
The muscular system obviously includes the muscles. The nervous system includes the nerves, brain and spinal cord. The endocrine system includes the thyroid gland, thymus, pineal gland, and pituitary gland. The cardiovascular system includes the heart and blood vessels.