Matching Pairs Tissues, Organs, and Body SystemsOnline version Review the tissue, organ, and body systems. by Janelle Ruiz 1 Muscular System 2 Circulatory System 3 Epithelial Tissue 4 Respiratory System 5 Digestive System 6 Nervous System 7 Connective Tissue Supports organs and joins tissue Brain, spinal column, axons Responsible for gas exchange (oxygen- carbon dioxide) with the outside environment Heart, veins, capillaries Lines organs and protects inside of body from outside world