Digestive system Flashcards
Contain information about membrane, glands and teeth
What are the 3 extrinsic salivary glands and 1 intrinsic gland?
- parotid glands
- submandibular glands
- sublingual glands
- buccal glands
What is the difference between the parotid, submandibular and sublingual glands and their duct locations?
P - anterior to the ear between masseter muscle and skin
- parotid duct enters vestibule next to 2nd molar, upper jaw
SM - along medial aspect of mandible
- duct runs beneath mucosa of oral cavity floor - opens at base of lingual
SL - under tongue - anterior to submandibular glands
- ducts on floor of mouth
What is the buccal gland and what is unique about it?
inside the oral cavity
- not regulated; always leaking
What are the 2 types of secretory cells in the salivary glands?
- serous (watery secretion)
- mucous (think mucin secretion)
What is the difference between incisors, canines and premolars?
I - chisel-shaped for cutting
C - conical for tearing, piercing
PM - bicuspids and molar (4-5 cusps) - grinding, crushing
What is the difference between primary dentition and permanent teeth?
PD - also called deciduous, milk or baby teeth (total = 20)
PT - larger, deeper roots all but 3rd molar appear at the end of adolescents (total = 32)
What is the dental formula: permanent dentition?
a way to identify teeth ex.
2I, 1C, 2PM, 3M (upper jaw)
2I, 1C, 2PM, 3M (lower jaw)
What are the 2 major regions of the tooth?
- crown
- root
What is the structure/ location of the tooth and what happens if the enamel producing cells degrade?
above gingiva, covered in enamel (ca2+)
- since the cell that makes enamel disappears at birth, we need to go to the dentist to fix damaged enamel
Where is the location of the teeth root and how many are there for each type?
in the jawbone
- 1 root for I, C and PM (only 1st upper PM - usually 2)
- 2-3 for M
What is the composition of the root and what does it attach the tooth to?
outer surface covered by calcified connective tissue (cement)
- attaches tooth to periodontal ligament
What does gingiva attach to and what happens with age?
enamel
- recedes to sensitive cement
What is inside the pulp cavity?
- cell bodies of odontoblasts
- connective tissue
- blood vessels
- nerve fibers
What does the pulp cavity extend to?
root canal
What is similar between enamel, dentin, and cement and which ones contain collagen?
calcification and resembles bone, but is avascular
- cement and dentin
What are cavities, dental plaque and periodontal disease?
- holes in the enamel
- accumulation of bacteria (biofilm)
- first sign is gingivitis which can be caused by calculus
What is the epithelium of the pharynx and what is the muscle that attaches to it?
- stratified squamous epithelium
- pharyngeal muscle = skeletal muscles
Where does the esophagus attach to the stomach, what is important about the sphincter and what is it supported by?
- cardinal orifice
- gastroesophageal sphincter (physiological sphincter)
- diaphragm also supports sphincter
What is the gastroesophageal sphincter not regulated by?
it is not regulated by thickening of muscles like the pyloric sphincter
What are the 4 layers of the esophagus?
- mucosa
- submucosa
- muscularis externa
- adventitia
What type of epithelia makes up the mucosa and how does it change in response to opening and closing?
nonkeratinized stratified squamous cells
- submucosa folds when esophagus empty
- folds flatten during food transit
What does the submucosa contain in the esophagus?
mucus-secreting esophageal glands
What type of muscle makes up the muscularis externa?
- skeletal muscle in upper 1/3
- smooth muscle in lower 2/3
What is the function of the stomach?
initiation of protein digestion and converts contents to chyme
