Digestive- Teeth and Salivary Glands Flashcards
part 2A
Teeth and their types
Teeth are for mastification
- Incisors (8): for cutting
- Canines (4): tearing and piercing
- Premolars (8): grinding and crushing
- Molars (12): grinding and crushing
How many teeth do adults have
32
Deciduous teeth
primary teeth are temporary;
I=8, C=4, M=8
20 teeth total
PRIMARY TEETH ROOTS GUIDE THE ADULT CROWN INTO PLACE
Dental Formula
divides the teeth into 4 quadrants
TOP 2 1 2 3
BOTTOM 2 1 2 3
order: incisor, canine, premolar, molar
Adult Teeth Numbering System
Starts at upper right quadrant, posterior molar is #1
Upper: 1-16
Lower: 17-32
Wisdom Teeth
third molars- 1, 16, 17, 32
Children’s Teeth Lettering System
Starts at upper right quadrant, posterior molar is A
Upper: A-J
Lower: K-T
Periodontal Tissue
gum, specialized epithelial tissue
Oral Cavity Innervations
Upper oral cavity: CN V2
Lower oral cavity: CN V3
Pulp Cavity
Center of teeth, receives blood vessels and nerves from the root canal (narrow tunnel @ base of tooth) which supports and nourishes the dentin
LIVING PART OF THE TOOTH
Dentin
non-living boney matrix of tooth, largest portion of tooth, surrounded by enamel
Enamel
above the gum (gingiva) line only, hardest known biological substance made of calcium phosphate crystals (Vit D and Ca2+)
Gingivitis
Bacterial infection of gums
Plaque
Sticky matrix on surface of teeth made by bacteria and trapped food particles
hardered= tartar
Saliva
pH: 7.0, 1-1.5L/day
Composition: 97% water, immunoglobulin A, lysozyme, Na+, K+, HCO3-, Cl-, mucus, amylase (digestive enzyme that breaks down sugar)
Functions of saliva
cleanse mouth, antibacterial, carbohydrate digestion started, aids in chewing and swallowing
Intrinsic Salivary Glands
minor glands, inside oral cavity associated with mucosa
- labial, palatal, lingual, buccal glands
Extrinsic Salivary Glands
major glands, not as associated with mucosa and connected to the oral cavity by salivary ducts
- parotid, sublingual, submandibular
Parotid Gland
largest, lateral face, parasympathetic CN IX
- Mumps: infected w myxovirus
- Parotid Duct: connection to oral cavity (1)
Submandibular Gland
beneath mandible (wrapping around posterior border of mylohyoid). CN V. Part inside oral cavity (sublingual), part outside (submandibular)
- submandibular (Wharton’s) duct: exits caruncle, inferior to tongue tip (1)
Sublingual Gland
Under tongue, anterior to tongue tip, CN V
- Sublingual (Rivinus’) Ducts: multiple ducts
Swallowing: Voluntary Phase
tongue pushes food to the back of the oral cavity (oropharynx)
Swallowing: Involuntary Phase
pharyngeal stage, food is moved into the oropharynx and laryngopharynx
- breathing stops and airways close
- soft palate and uvula lift to close off nasopharynx
- vocal cords close
- epiglottis is bent over airway as larynx lifts
Swallowing in new borns
in newborns the epiglottis and the soft palate touch, the epiglottis is above the level of the soft palate and the larynx descends by 2 years of age
- allows the baby to nurse and breath at the same time
