University:
Glendale Community College
Course:
BIO160 | Introduction to Human Anatomy and Physiology
Academic year:

2019
Views:

45

Pages:

9
Author:

Ruben Owens

• Gingiva (gums) is a mucous membrane on the alveolar bone around teeth • Enamel covers the crown – 90% mineral (hydroxyapatite) – only formed during tooth development – hardest material in the body – irreplaceable • Dentin is 70% mineral and is living, innervated tissue • Cementum surrounds the roots and is 50% mineral much like bone • Periodontal Ligament is composed of collagen fibers that anchors tooth to alveolus – requires Vitamin C • Root Canal leads into pulp cavity and contains nerves and blood vessels Teeth and Gums Anatomical Crown – part of tooth covered with enamel Clinical Crown – part of tooth exposed above the gingiva (increases with receding gums) Permanent and Deciduous (Baby) Teeth (a) Adult dentition at age 6-25 years (b) Baby teeth by 2 years old Permanent and Deciduous Teeth Saliva • Functions of Saliva – Moisten food, begins digestion, cleanse teeth, inhibit bacteria, bind food together into bolus and lubricate food for swallowing • Saliva is a hypotonic solution of 99.5% water with the following solutes: – – – – – – amylase = begins starch digestion lipase = helps digest fat in the stomach mucus = aids in swallowing lysozyme = enzyme that kills bacteria immunoglobulin A = inhibits bacterial growth electrolytes = Na+, K+, Cl-, phosphate & bicarbonate • Saliva pH is 6.8 - 7.0 Salivary Glands • 3 pairs of large extrinsic glands are connected to the oral cavity by ducts: parotid, submandibular and sublingual • Small intrinsic glands are found throughout the mouth under the mucous membrane of the lips, cheeks and tongue secrete a small amount of saliva all the time. Salivation • About 1 to 1.5 L of saliva produced per day. • Parts of the brain that respond to the sight, smell and thoughts of food can cause salivation. – parasympathetic stimulation of salivary glands produces large volume of thin saliva – sympathetic stimulation of salivary glands produces small volume of thicker saliva, with more mucus • Sialoliths are “stones” that can develop in salivary glands or salivary gland ducts.