1. Locate the salivary glands, which on the sides of the neck, between muscles and the external layer of skin. You should not have to cut very deep. Peel the skin back to expose the salivary glands. They are soft spongy tissue that secrete saliva and amylase (an enzyme that helps break down food). The texture of these glands resembles chewing gum.
There are three salivary glands - the sublingual (yellow pin), submaxillary (green pin), and parotid (red pin). The parotid is easiest to find, it lies just beneath the ear and extends to the neck. See if you can find the others also.
2. Find the lymph glands which lie anterior to the salivary glands. Lymph glands are dark and circular and are pressed against the jaw muscles
3. Tease away the muscles of the neck to reveal the trachea. The trachea is identifiable by its ringed cartilage which provides support. The esophagus lies behind the trachea, but can be difficult to locate in this area.
4. Locate the larynx, which is just anterior to the trachea. The larynx is the voicebox, and allows rats to make squeaking noises.
In this photo, the esophagus is not visible, it lies behind the trachea. The trachea is easily distinguished from the esophagus because it has rings on its surface.