Final answer:
Bloodletting is a historical medical practice where a sick person is intentionally made to lose blood. It was believed to be beneficial but is now considered ineffective and abandoned. Blood plays a vital role in delivering nutrients and oxygen to cells and removing waste products.
Step-by-step explanation:
Bloodletting is a historical medical practice where a sick person is intentionally made to lose blood. It was believed to be beneficial for a variety of illnesses, but its effectiveness started to be questioned in the 1800s and was eventually abandoned by the medical community. Blood, as a fluid connective tissue, plays a vital role in delivering nutrients and oxygen to cells and removing waste products, so the loss of blood can have detrimental effects on the body.