Stomach from a neonatal dog, longitudinal section

Polarised light micrograph of a longitudinal section of the stomach of a neonatal dog. This sample is from a vintage prepared slide from the period 1870 - 1905. Blood vessels were injected with dye (carmine; red) before fixing and sectioning the tissue in order to visualise the capillaries in the tissue. This was a newly developed technique at that time. The capillary supply to the muscular folds or rugae of the stomach is visible. These gastric folds allow the stomach to expand when food enters it and also help move food through during digestion. Composite of 26 individual images. Horizontal width of image is 16 mm.