Cast of the trachea, bronchi and bronchioles of a domestic dog.

This resin cast shows the branching of the windpipe or trachea (centre top) into bronchi and then bronchioles through the lungs. Air is drawn into these ever-smaller channels until they reach the alveoli, where gas exchange between the lungs and the bloodstream occurs. Image courtesy of the RVC.

Resin cast of a canine kidney

Plastinated cast of the blood vessels (pink) supplying the kidney and the renal pelvis (yellow, not the same as the pelvic bone), which collects urine and carries it to the bladder. Plastination and cast-making provide an excellent way to study complex networks of vessels such as this one, and help biologists to examine them without the…