Mesenchyme is a type of tissue characterized by loosely associated cells that lack polarity and are surrounded by a large extracellular matrix. Mesenchymal cells are able to develop into the tissues of the lymphatic and circulatory systems, as well as connective tissues throughout the body, such as bone and cartilage.esenchyme is a type of tissue characterized by loosely associated cells that lack polarity and are surrounded by a large extracellular matrix. Mesenchymal cells are able to develop into the tissues of the lymphatic and circulatory systems, as well as connective tissues throughout the body, such as bone and cartilage.