Final answer:
The lymphatic system is responsible for releasing fluid from blood vessels to nourish the body's cells and tissues, and it also plays a significant role in both the digestive and immune systems.
Step-by-step explanation:
The system in the body responsible for releasing fluid from the blood vessels to nourish cells and tissues is the lymphatic system. This system includes a network of lymph vessels and ducts that collect excess tissue fluid, known as lymph, and transport it to the bloodstream. Additionally, the lymphatic system is crucial for transporting dietary lipids from the digestive system and for carrying cells of the immune system throughout the body.