Tags: Muscle.
In biology an organ (or viscus) is a collection of tissues joined in a structural unit to serve a common function. In anatomy a viscus /ˈvɪskəs/ is an internal organ and viscera is the plural form.There is a main tissue parenchyma and sporadic tissues stroma. The main tissue is the one that is unique for the specific organ. For example the main tissue in the heart is the myocardium while sporadic tissues include the nerves blood and connective tissues.
