Tissue: A group or layer of cells that perform specific functions. For example, muscle tissue is a group of muscle cells.issue: A group or layer of cells that perform specific functions. For example, muscle tissue is a group of muscle cells.
1 The skin is a barrier to the outside world protecting the body from infection, radiation, and extremes of temperature.  There are many types of wounds that can damage the skin including abrasions, lacerations, rupture injuries, punctures, and penetrating wounds.
There are three main types of skin grafts: A split-thickness graft is the most commonly used type of skin graft. It removes only the epidermis (the top layer of skin) and part of the dermis (the middle layer of skin). This allows the source site to heal more quickly.