Salivary Glands

Location of 3 Glands

There are three pairs of salivary glands: the parotid, sublingual, and submandibular glands. The parotid gland, near the ear, is the largest. The sublingual gland is beneath the tongue, and the submandibular gland is lower in the jaw. These glands produce saliva, which is primarily waterThe universal solvent essential for life. and slightly acidicA solution with a pH below 7, having a higher concentration of H⁺ ions., containing enzymesProteins that speed up chemical reactions in the body. like amylase and antibodies for immune defense. Salivary glands consist of serous cellsThe basic structural and functional units of life. (producing watery secretions) and mucous cells (producing mucus).

Saliva

Saliva is primarily water. It is slightly acidic owing to these four things listed below. Yes, you have growthAn increase in size and number of cells. factors in your saliva. These factors encourage mitosis and turnover of the stratified squamous keratinized epithelium of the mouthThe opening of the digestive tract where food enters and mastication begins.. You have antibodies mostly IgAs that are common to saliva and other secretions of the body. Your saliva does contain enzymes, it contains more than these enzymes listed here. Lipase is an enzyme that is capable of performing chemical digestion on lipidsOrganic molecules including fats, oils, and steroids.. There are two kinds of lipase, one that is capable of acting at relatively neutralA solution with a pH of 7. pHA measure of hydrogen ion concentration in a solution. levels. This lipase is found in your saliva and begins the chemical digestion of lipids. There was also a lipase that works at a much lower pH. The pancreasA gland that produces digestive enzymes and hormones like insulin and glucagon. secretes this lipase into the small intestine. Here, it finishes digesting the lipids that the salivary lipase started. A lysozyme is an enzyme that functions more in encouraging innate immunity then it does in chemical digestion.  Isozymes are able to breakdown a protein called peptidoglycans that is present in bacterial plasmaThe liquid component of blood. membranes.

Histology

The Histology of salivary glands is deceptively simple. We are at the point in this course where we must identify structures we have already seen. We need to also identify structures in histological pictures. Present in this picture above are many arterials and capillariesThe smallest blood vessels where gas, nutrient, and waste exchange occurs between blood and tissues.. I can recognize some by their tunica intimaThe innermost layer of a blood vessel, consisting of endothelium and a thin connective tissue layer. and smooth muscle. I can recognize others by these little red blood cells. There are ducts through which the saliva is collected and distributed into the mouth. Ducks are usually lined by simple or stratified cuboidal cells and there is a collection of ducts right down here. There are two cell types that are specific to salivary glands. Serous cells secrete a watery secretionThe process of moving substances from the blood into the nephron tubule to be excreted in urine. and this bulk of cells up here are serous cells. There are also mucus cells that secrete a more viscous product with a higher pH. These cells have a more puff like appearance and do not take up the stain as readily as the serous cells