Using a customer supplied envelope, an individual can mail a Priority Mail Express letter envelope weighing one ounce up to sixteen ounces for $31.20 plus the extra fee of $12.50 to add Sunday/Holiday Delivery.
muscle cell-an elongated contractile cell that forms the muscles of the body. muscle fiber, muscle fibre. fibre, fiber-any of several elongated, threadlike cells (especially a muscle fiber or a nerve fiber).
A muscle cell is a special kind of cell that makes up an organism's muscle tissues. The muscles allow independent movement and regulate biological functions such as digestion and heartbeat. These cells are further specialized into distinct types based on their location and functions.