USPS Priority Mail Express is a guaranteed way to send documents and packages to a destination overnight or in one to two days on any day of the year, including Sundays and holidays. If the US Postal Service doesn't deliver your package on time, they will refund the full delivery cost to you. Items under 70 pounds can be sent through Priority Mail Express to any address in the United States. Priority Mail Express comes with up to $200 in insurance and delivery tracking for free. USPS is the only overnight shipping carrier that is allowed to deliver packages to a P.O. Box address.
Muscular system. Definition. noun. An organ system comprised of skeletal muscles, smooth muscles, and cardiac muscles that are responsible for providing strength, keeping up balance, maintaining posture, allowing movement and producing heat. Supplement.The animal body is comprised of various organ systems and the muscular system is one of them.he muscular system includes all the muscle tissues such as the skeletal muscle tissues, smooth muscle tissues, and cardiac muscle tissues. The skeletal muscles are muscles attached to the bones and are responsible for the voluntary movements of the body.
Muscular. The muscular system is comprised of the sum total of muscles throughout the body that move the skeleton, maintain posture through steady contraction, and generate heat through cell metabolism. Humans have three types of muscle.Read More.uscular. The muscular system is comprised of the sum total of muscles throughout the body that move the skeleton, maintain posture through steady contraction, and generate heat through cell metabolism. Humans have three types of muscle.