1. The skeletal system shares the joints with the muscular system. Joints are the points of contact between two or more bones. They allow for movement and provide support.

2. The skeletal system shares the blood with the circulatory system. Blood vessels run through the bones and supply them with oxygen and nutrients.

3. The skeletal system shares the bone marrow with the hematopoietic system. Bone marrow is the soft tissue inside bones that produces blood cells.

4. The skeletal system shares the calcium with the endocrine system. Calcium is a mineral that is essential for bone health. It is regulated by the hormones parathyroid hormone and calcitonin.

5. The skeletal system shares the vitamin D with the digestive system. Vitamin D is a nutrient that is essential for the absorption of calcium. It is produced in the skin when exposed to sunlight and can also be obtained from food sources.