Januari 30, 2017
>>dr. ketchum: so we’re going to start withthe salivary glands. we have three major types of salivary glands. we have sublingual. ifyou think about sub, what sub means, sub means “below.†so the sublingual gland is belowthe tongue. submandibular, so that would be below the mandible, and then there’s theparotid gland. so if you look here, this is the gland that would be associated with thejawline—just above the jawline, but in front of the ear. so they all secrete saliva, but let’s lookat what saliva contains. saliva contains these bicarbonate ions. bicarbonate ions will attemptto make the saliva alkaline. anywhere from slightly acidic to neutral to alkaline isthe ph of the saliva. some of the things that
we eat and the various bacteria in our mouthcan alter the ph. so these bicarbonate ions serve to make our mouth a little more neutralto somewhat alkaline. the saliva also contains mucus. the mucus lubricates the food, becausewhen you chew or you masticate your food, you don’t want to cause abrasions in thelining of your mouth. so for example: i don’t know if you’ve eaten some toast that you’veover-toasted and it’s practically burnt, and it forms those abrasions that you get or that roughtexture on the roof of your mouth and it’s pretty sore for a few days? the mucus is thereto help protect things like that from happening. you also have enzymes associated with thesaliva. these include salivary amylase and lingual lipase. salivary amylase is goingto break down starch; starch digestion begins
in the mouth. lingual lipase will break downfats. however, lingual lipase is not activated until it reaches the stomach. the saliva alsocontains lysozymes—not lysosomes. don’t confuse the two. lysozymes are antibacterial,so those are going to kill any bacteria that may have come into your mouth with your food.they can also help prevent tooth decay.
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