This is a so cool paper craft model from Horst Kiechle. This torso was designed for the Science Lab of the International School Nadi, and with removable organs. Templates for some of the organs are available: STOMACH, LIVER, HEART, LEFT KIDNEY, RIGHT KIDNEY, PANCREAS, LEFT LUNG and RIGHT LUNG.
Recommended 200gms/sqm white card paper to build it. You can download this cool paper model from here: Anatomical Model - Paper Torso Free Papercraft Download