Digestive System: Oral cavity/mucosa, Tongue, Teeth, Salivary glands Flashcards
What are the functions of the digestive system?
Ingestion, mastication, secretion, absorption, elimination of wastes, motility, hormone release, chemical digestion
What makes up the oral cavity?
Tongue, teeth, minor and major salivary glands, tonsils, lips
What are the 3 types of oral mucosa?
Masticatory mucosa, lining mucosa, specialized mucosa
Where is the masticatory mucosa found?
Gingiva and hard palate
What type of surface epithelium makes up the masticatory mucosa?
Keratinized or parakeratinized stratified squamous epithelium (superficial cells of parakeratinized stratified squamous cells keep their nuclei)
What are the 2 parts of the lamina propria of the masticatory mucosa?
Papillary layer- thick loose CT, has blood vessels, nerves, sensory receptors, some Meissner’s corpuscles
Reticular layer- more dense ct
Where is the lining mucosa of the oral mucosa found?
Soft palate, underside of tongue, floor of mouth, cheeks, lips
What makes up the surface epithelium of the lining mucosa?
Generally nonkeratinized stratified squamous
Occasionally parakeratinized stratified squamous
Keratinized stratified squamous (lips, vermillion border)
What areas of stratified squamous is thicker than the areas of keratinized stratified squamous?
Nonkeratinized
What makes up the lamina propria of the lining mucosa?
Loose ct with blood vessels and nerves
What makes up the submucosa of the lining mucosa?
More dense ct (found in most places, can have minor salivary glands, sebaceous glands, larger blood vessels and nerves)
Where is the specialized mucosa of the oral cavity found?
Dorsal surface of tongue
What makes up the surface epithelium of specialized mucosa?
Keratinized stratified squamous on filiform papilla
Stratified squamous on all other papillae
What are the general functions of the specialized mucosa?
Move food and taste
How is the mucosa of the tongue?
Thicker dorsally, thinner and smoother posteriorly
What surface epithelium makes up the tongue?
Specialized, includes papillae: filiform, fungiform, foliate, vallate (circumvallate)
What glands are associated with vallate papilla and what is their function?
Small salivary glands (von Ebner), they function to produce serous fluid to cleanse the taste buds on these papillae
Which papillae are taste buds NOT included on?
Filliform papillae
What makes up the lamina propria of the tongue?
Loose ct; adipose possible
What makes up the submucosa of the tongue?
Considered present on tongue but adipose is possible
What is unique about the submucosa of the tongue?
Contains lingual salivary glands that produce same products as the major salivary glands
What are the intrinsic tongue muscles and how are they arranged?
Superior longitudinal muscle, Vertical muscles alternating with Transverse muscles, Inferior longitudinal muscle
*arranged from dorsal to posterior within the tongue(?)
What is the function of the intrinsic tongue muscles?
Change shape of tongue (important for phonation and moving food around)
What are the layers of the teeth from outside to inside?
Ameloblasts, enamel, dentin, predentin, odontoblast, dental papilla
What are the ameloblasts made up of and what and what’s their function?
Polarized columnar cells
They produce enamel
*ameloblasts lost following tooth eruption
What is unique about enamel and what is it made of?
2mm thick, it is the hardest substance in the body
Made of interlinked enamel rods
Can enamel be made after tooth eruption?
No
What is unique about dentin and what does it contain?
It is harder than bone
Contains thin dentinal tubules containing nerves and cell processes of odontoblasts
What is the precursor to dentin before mineralization?
Predentin
What makes up odonotoblasts and what’s their function?
Columnar cells lining pulp cavity
They repair and produce dentin (maintain dentin)
What makes odontoblasts so different from ameloblasts?
Odontoblasts survive in adults unlike ameloblasts
What is dental papilla/dental pulp made of and what is a potential problem?
CT with many blood vessels and nerves
Excessive inflammation can be a problem
What are the three salivary glands?
Parotid, Submandibular, Sublingual
What is unique about the parotid gland?
It is the largest salivary gland and produces ~30% of total salivary output; also it is 100% serous producing
What is the parotid gland most affected by?
Mumps– facial nerve passes through
What happens to the parotid gland as one ages?
It becomes infiltrated with adipose
What are the products secreted by the parotid gland?
Salivary amylase (alpha amylase–> breaks down carbs)
Lysosome
Secretory IgA
Is the submandibular gland smaller than the parotid?
Yes
Can the submandibular gland become fatty?
Yes, infiltration possible by midlife
Is the submandibular gland 100% serous producing?
No, it is a mixed gland producing mucus AND serous products; ~80-90% serous producing
What is unique about the submandibular gland?
It has serous demilunes
Is the sublingual gland the smallest salivary gland? How much salivary output does it contribute to?
Yes it is the smallest salivary gland, ~5% of total salivary output
Is the sublingual gland mixed?
Yes, it produces mucus AND serous products; ~8% mucus producing
Where do all of the serous producrs of the sublingual gland come from?
Serous demilunes; no separate serous acini
What are the functions of the saliva?
Lubricating and cleansing for the oral cavity
Antibacterial activity
Dissolves food materials for taste sensation
Initiates digestion: salivary amylase/lipase
Aids swallowing by moistening food, helps form bolus
Wound healing due to clotting factors, epidermal growth factor present
What is saliva secretion stimulated by?
Autonomic efferent impulses
What will parasympathetic impulses do to saliva secretion?
Increases amount of watery secretion
What will sympathetic impulses do to saliva secretion?
Result in a decreased amount of saliva with a thicker consistency–> dryer oral cavity
What does the mucosa of the luminal wall include?
Surface epithelium, lamina propria (loose ct), muscularis mucosae (smooth muscle)
What does the submucosa of the luminal wall include?
More dense CT, larger blood vessels, submucosal (Meissner’s) plexus which influences mucosa
What plexus is found in the muscularis externa of the luminal wall, where is it found, and what is its function?
Myenteric (Auerbach) plexus
Found between circular and longitudinal muscle layers
Function is to influence muscularis externa
What type of muscle is the muscularis externa and how is its orientation?
Smooth muscle
Orientation: inner circular, outer longitudinal (normal)
Where is the serosa/adventitia found in the luminal wall?
Next to the muscularis externa
What is serosa in the luminal wall?
Edge of simple squamous epithelium (can contain CT), it is serous producing
What is adventitia in the luminal wall?
CT, seen in vertical organs
