Digestive System I Flashcards
What are the two subdivisions of the oral cavity?
- Vestibule
2. Oral Cavity Proper
What areas of the oral cavity are included in the vestibule region?
behind the lips, in front of the teeth with the mouth closed
What areas of the oral cavity are included in the oral cavity proper?
Behind teeth, roof of mouth, tongue, oral pharynx
What is the function of the tonsils? Where are they located?
Surveillance system for immune system
Make a ring around oral pharynx
What are the three types of mucosa?
- Masticatory
- Lining
- Specialized
What are the characteristics of the masticatory mucosa? Where is it found?
Keratinized/parakeratinized
Gingiva, hard palate
What is parakeratinization? Where is it found?
Still some nuclei
found in gingiva, hard palate
What are the characteristics of the lining mucosa? Where is it found?
Nonkeratinized
Lips, cheeks, soft palate
What are the characteristics of the specialized mucosa? Where is it found?
specifically in the regions of the taste buds on lingual papillae on the dorsal surface of the tongue;
contains nerve endings for general sensory reception and taste perception.
What are the three aspects of the mucosa?
Epithelium
Lamina papilla
Muscularis mucosa
What are the three aspects of the submucosa?
Dense connective tissue, blood and lymphatic vessels, and the submucosal plexus (plexus of Meissner)
What are the three layers of the lips?
- Cutaneous (external)
- Red (vermillion)
- Oral Mucosa
What are the characteristics of the cutaneous/external layer of the lips?
Keratinized
Hair follicles
Sebaceous and sweat glands
Thin
What are the characteristics so the red (vermilion) layer of the lips?
Thick Keratinized Papillae large stratum spinosum deep rete ridges full of LCT
What gives lips their red color?
The deep rete ridges full of LCT, which includes blood vessels, in the red/ vermilion layer of the lips
In what layer of the lips are the Meisner’s corpuscles located?
The red/vermilion layer
What are the characteristics of the oral mucosa?
Thick epithelial layer
para/nonkeratinized
What does the submucosa of the cheeks do?
Anchors mucosa to underlying skeletal muscle
What characteristics of the lamina propria allow for the movement of skeletal muscle in the cheeks?
The lamina propria is less thick
Are the cheeks kerintinzed? Is the lamina propria and submucosa dense or loose?
Nonkeratinized
Dense
What two parts of the gingiva does the lamina propia bind to?
Periosteum and periodontal ligament
What do gingiva lack? (2)
Lack submucosa
Lack glands
Are gingiva keratinized?
Keratinized
What is the function of the gingiva?
Barrier to lower regions of the tissue, blocking micro bacteria etc
What is the function of the hard palate?
Assists tongue in preparation of bolus
What type of mucosa lines the hard palate?
Masticatory mucosa
What is the submucosa of the hard palate made of?
Adipose tissue
What function does the palatine raphe severe in the hard palate?
Directly attaches to palatine bone which makes the hard palate immovable
What is the function of the soft palate?
Prevents passage of food/fluids between oral and nasal pharynges
What type of mucosa lines the soft palate?
Lining mucosa
Does the soft palate have a thick or shallow lamina propia?
Shallow
Does the hard palate have a thick or shallow lamina propia?
Thick
What are the three types of salivary glands? What are the relative percentages of saliva they produce?
- Parotid gland (25%)
- Submandibular gland (65-70%)
- Sublingual gland (5%)
Where is the paratid gland located? Where does the duct open?
Temporal region
Opens at second molar
Where is the submandibular gland located? Where does the duct open?
Submandibular triangle of the neck
Ducts opens at lingual frentum
Where is the subligual gland located? Where does the duct open?
Sublingual folds at floor of oral cavity
Numerous ducts
What salivary gland contains assinide serous along? How does this cause the salivary gland to stain?
Paratid (serous) gland
Stains darkly
What salivary gland contains a mix of assinide serous gland and mucous gland? How does this cause the salivary gland to stain?
Submandibular gland
Stains light - clear
What salivary gland contains more mucous than serous overall? How does this cause it to stain?
Sublingual gland
Stains very light
What does the muscular core of the tongue consist of? Type of muscle, how many planes?
Bundles of striated muslce
Arranged in 3 different plans for diverse movement
What is the muscle core anchored to mucosa of tongue by?
Lamina propria CT
What are the characteristics of the ventral surface of the tongue? keratinized? thick or think lamina propia? Why type of mucosa?
Nonkeratinized
Thin lamina propia
Lining Mucosa
What type of mucosal lining does the dorsal surface of the tongue have? What is the anterior 2/3 made of? The posterior 1/3?
Specialized mucosa
anterior 2/3 = lingual papillae
posterior 1/3 = lymphoid aggregates
What are the sulcus terminales?
Circumvallate papillae that create a V on the tongue separating the anterior 2/3 and posterior 1/3
What are the four types of lingual papillae?
- Filiform
- Foliate
- Fungiform
- Circumvallate
Filiform lingual papillae; abundant? do they have taste buds? keratinized? grooved?
Most abundant
No taste buds
Lp grooves
Keratinized
Foliate lingual papillae; location? grooved? taste buds? ducts?
On the sides of the tongue
Deep groove with duct entrance at the bottom
Taste buds on lateral side
What is the purpose of the ducts in foliate lingual papillae?
Tastants and wash away taste buds ?
How do we distinguish papilla on foliate lingual papillae?
Primary papilla = large
Secondary papilla = individual papilla located within the primary papilla
Fungiform lingual papillae; location? taste buds? color? distinguish papillae?
Scattared across tongue
Taste buds close to the surface
Red because LCT is close to the surface
Primary and secondary
Circumvalle lingual papillae; size? location? taste buds? function?
Huge
Taste buds on the lateral side of the groove
Takes up secretants, solubilize, wash away
What are taste buds responsible for?
5 stimuli of taste
- Sweet
- Salty
- Bitter
- Sour
- Umami
What are the three principal cell types in taste buds?
- Neuroepithelial cell
- Supporting Cell
- Basal cell
What do neuroepithelial cells in taste buds look like? What do they synapse with?
Large, light staining nuclei
Apical to basal surface
Synapse with gustical afferent neuron
What do the nuclei of the supporting cells of taste buds look like?
Dark, elongated nuclei
What do the nuclei of the basal cells of taste buds look like? What domain do they fall in?
Small, dark nuclei
Basal domain only
STEM Cells
How are neuroepithelial cells and supporting cells used in the cellular pathway of taste?
Tastant binds to receptors on microvilli on the cells that extend into the taste pore > electrical signal
What kind of receptor binds to bitter, sweet, and umami? What does the rest of the signaling pathway look like?
Tastant binds > GPCR > PLC > Ca release > NT
What does the cellular pathway look like for sour signaling?
sour > H+ > proton channels > Ca release > NT
What does the cellular pathway for salty look like?
Salt > Na > influx through channels > Ca release > NT
How many deciduous (primary) teeth in children?
20
The ___ deciduous are replaced by ___ permanent (secondary) teeth in adults, plus ___ additional teeth
20, 20, 12
Teeth are composed of a ____ and a _____
Crown
Root
When do teeth form? When do they rupture?
Form during gustation
Rupture at 6 months of age
When do you lose your deciduous teeth?
6-12/13 years old
What is the enamel of the tooth?
hard outer coating
96% mineralized
What are the three layers of specialized tissue in the tooth?
Enamel
Cementum
Dentin
What is the difference between the critical crown and anatomic crown of the tooth?
Critical crown is seen
Anatomic crown is under the surface
What is dentin? what percentage is mineralized?
70% mineralized
What is cementum? % mineralized?
Covers root of the tooth
50-55% mineralized
What is the central pulp cavity? what tissue type? vascular or avascular? function?
Vascularized
Highly ordered CT, LCT
Supports the rest of the tooth
What is the periodontal ligament? What tissue type is it?
Locks the tooth into place with limited movement
Comes out of the bottom of the tooth and binds to bone
Fibrous CT
What is the alveolar bone?
Bony housing surrounding root of tooth
From the jaw
What is the gingiva? What is it attached to?
Gums
Oral mucosa located around neck of tooth
Attached to teeth and underlying alveolar bony tissue
What are the four stages of tooth development?
- Bud Stage
- Cap Stage
- Bell Stage
- Apositional Stage
Talk me through tooth development
- Bud Stage; epithelium envelopes in and cells are recruited from the mesoderm to form the pulp and root
- Cap Stage; you have early-stage amyloplasts, cells begin to congregate to form the dental papilla
- Bell Stage; closing off from oral epithelium, becomes a contained structure, start to see jaw bone making the boney socket
- Apositional Stage; the developing tooth is completely separate, begins to see layers (dentin, enamel, pulp)
What do odontalblasts do?
Synthesize and secrete denten away from the pulp canal
What do ameloblasts do? How long do they live?
Synthesize the enamel
Die once the tooth ruptures, no new generation of the enamel
l
.
What is cementum? How is it made? % mineralization?
Cementum lines the exterior of the root
70-75% mineralized
Cementoblasts produce cementoid and then get surrounded and become cementocytes
What are Sharpey’s fibers? Tissue type? Where are they located?
Type I collagen fibers released by cementoblasts
They extend from the periodontal ligament into the cementum
What are Dental Caries? How do they form?
Cavity
The enamel layer begins to wear away and exposes dentin below
What are Viridin Steptacoxy?
Type of bacteria
Fermenting sugars > biofim (plaque) formation > recruitment of other bacteria > bacteria goes beneath the gum line (disrupts the barrier)
Can also cause periodenotal disease
What is the gingical sulcus?
Makes barrier between outside oral cavity and ??
