Final answer:
A closed wound from a blow to the body is known as a contusion, characterized by bruising and swelling without breaking the skin.
Step-by-step explanation:
A closed wound caused by a blow to the body is commonly known as a contusion. This type of injury occurs when a part of the body is struck with force but the skin is not broken. Contusions can result in bruising and swelling due to the impact of a blunt instrument causing injury to the underlying tissue and blood vessels. In contrast, other types of wounds like abrasions, lacerations, and fractures have distinct characteristics. An abrasion is a scrape on the skin, a laceration is a cut or tear, and a fracture refers to a broken bone, which can be either open (with broken skin) or closed (skin intact).