Question

why in lab do you usually fill the dissecting tray with about 2-4 cm of water?

Answer 1

Dissecting trays are rectangular trays made of aluminium. The trays are filled with wax which privide a soft surface for the attachment of the dissected specimen. Pins are used to attach the specimen.

Trays are useful for detailed study of the specimen in terms of anatomical features, identification of organs or a part thereof, practical examination or oral examination display.

Water is known as a Universal solvent. It has the ability to dissolve almost anything. It is used for washing, cleaning and removal of smaller fragments during dissection. Thus, if water is filled upto 2-4 cm level, removal of unwanted or smaller parts/particles becomes easier, it also provides a medium of refraction as light from the specimen will reach our eyes from water to air( change of medium). This can facilitate angular vision as the ray of light might bend . Very often during dissection of an animal, blood comes out or skin layers or fat particles are removed. Presence of water facilitates easy removal of such alongwith frequent washing of hands during the dissection process. The dissecting instruments are also contaminated during the dissection process whereby the substances are found to be attached. Such substances can be removed easily by providing a jerk in the water level where the stuck substances get loosened and fall off. After the dissection procedure, the specimen can be removed, the tray can be washed with water, dried and reused.