Histology of the nasal and oral cavities

Question 1

Respiratory epithelium

Answer 1

Pseudostratified columnar ciliated epithelium

contains goblet cells
non ciliated basal cells

contains a lamina propria which has a rich vascular network with a complex set of capillary loops

Question 2

What are the three regions of the nasal cavity

Answer 2

Nasal vestibule: just inside the nostrils lined by skin

Respiratory region: inferior 2/3 of nasal cavities, lined with respiratory mucosa

Olfactory region: Located at the apex (upper 1/3) lined by specialized mucosa

Question 3

What is the function of the nasal cavity

Answer 3

adjust temperature and humidy of inspired air

enhanced by large surface area provided by the turbinate bones

Question 4

What are paranasal sinuses and what are their functions

Answer 4

air filed spaces in the bones of the walls of the nasal cavity

extensions of the respiratory region of the nasal cavity so it is lined by respiratory epithelium

sinuses communicate with nasal cavities via openings into the respiratory mucosa
-ciliary movements push mucus produced in the sinuses

Sinuses are often subject to acute infection after viral infections

Question 5

What type of cells are Nasal vestibule

Answer 5

Keratinized stratified squamous epithelium

Question 6

What type of cells are the respiratory region

Answer 6

pseudostratified columnar ciliated epithelium

Question 7

What are the hallmarks of olfactory mucosa

Answer 7

Dramatically thicker
lacks goblet cells
contains olfactory glands
pseudostratified ciliated columnar epithelium
contain receptors for sense of smell

Question 8

What are the three types of cells found in olfacory mucosa

Answer 8

basal cells: stem cells for olfactory receptors and supporting cells

Brush cells: ciliated, columnar epithelial cells in contact with CN V

Supporting/sustentacular cells: provide mechanical and metabolic support to olfactory receptor cells

Question 9

What are the details of Olfactory receptor cells

Answer 9

have single dendritic process

specialized, non motile cilia with odorant recepters

ligand binding causes signals to be sent to olfactory bulb

Question 10

Oral cavity mucosa is broken into three layers?

Answer 10

Lining
masticatory
specilized mucosa

epithelium is stratified squamous but varying degree of keratinization

Question 11

Lamina puropria function and layers

Answer 11

supports the mucosa via dense collagenous tissue

it is connective tissue of fibroblasts, WBCs, and collagen fibers

Papillary layer: superficial, loose CT with neurovasculature

Dense layer: deep, dense irregular CT with large amounts of fibers

Question 12

Masticatory mucosa

Answer 12

found on hard palate, gingiva and dorsal surface of tongue

keratinized and or parakeratinixed stratified squamous epithelium

highly interdigitated with rete ridges and papillae

thin or abscent submucosa

Question 13

Lining mucosa and its layers

Answer 13

found on lips, cheeks, alveolar mucosal surface, floor of the mouth, inferior surfaces of the tongue and soft palate

Non keratinized stratified squamous epithelium but may be parakeratinized in select locations

consists of three layers

stratum basale: single layer of cells on the basal lamina

stratum spinosum: several layers thick

stratum superficiale: most superfical layer

Question 14

Specialized Mucosa

Answer 14

associated with sensation of taste

restricted to the dorsal surface of the tongue

contains papillae and taste buds resposible for gustation

found on tongue

Question 15

What type of layers does the tongue contain

Answer 15

masticatory and specialized mucosa

keratinized stratified squamous and lingual papilale and taste buds

Question 16

Lingual Papilla

Answer 16

structures of keratinized epithelium with lamina propria

small elevated structures of specialized mucosa

some of which are associated with taste buds

Question 17

Filiform Papillae

Answer 17

Not associate with taste

look like a pinecone

move food torward pharynx for swallowing

give dorsal surface of tongue velvety texture

shaped like fine pointed cone

no taste buds

Question 18

Foliate Papillae

Answer 18

Associated with taste

vertical ridges on lateral surface of tongue in more posterior regions

provide taste sensation

Question 19

Fungiforum Papillae

Answer 19

Dorsal surface of tongue found in lesser numbers

provide taste sensation

Question 20

Circumvallate papillae

Answer 20

7-15 raised mushroom shaped structures, anterior to sulcus terminalis

sunken apperance surrounded by trench

hundreds of taste buds present

Question 21

Taste Buds

Answer 21

Barrel shaped organs that perceive food molecules

comprised of 30-80 spindle shaped cells that extend from the basement membrane

each taste bud can discern all tastes but tend to concentrate on two

can also be found on glossopalatine arch, soft palate, posterior surface of epiglottis and posterior wall of pharynx

Question 22

Neuroepithelial sensory cells

Answer 22

elongated cells that extend from the basal lamina of the epithelium to the taste pore

synapse with a afferent sensory neuron (CN: VII, IX, X)

Question 23

Supporting cells

Answer 23

elongated cells that extend from the basal lamina to the taste pore

contain microvilli on their apical surface and do not synapse with the nerve cells

Question 24

Basal cells

Answer 24

small cells located in the basal portion of the taste bud near the basal lamina and stem cells for the two other cell types

Question 25

Tonsils

Answer 25

Large irregular masses of aggregated lymphoid tissue

located in the mucosa of posterior oral cavity, oropharynx and nasopharynx

Help protect against inhaled or ingested substances

can be partially encapsulated

Question 26

Palatine tonsil

Answer 26

Lined with nonkeratinized stratified squmous epithelium

possess 10-20 deep invaginations, tonsillar crypts

Epithelial lining densely populated with lymphocytes

dense connective tissue act as a partial capsule

Question 27

Pharyngeal tonsil

Answer 27

SIngle structure

posterior wall of nasopharynx

covered with pseudostratified columnar ciliated epithelium

thin underlying capsule

invaginated mucosa with shallow infoldings but no crypts

Question 28

Lingual tonsil

Answer 28

Positioned along base of tongue

covered with stratified squamous epithelium

possesses germinal centers

varying number of crypts

lacks a capsule

Question 29

Teeth

Answer 29

Divided into the crown and root

Crown projects into oral cavity and protected by enamel

root is embedded in the alveolar ridge of an alveolus (tooth socket)

bulk of tooth is made up of dentin

dentin encloses a central pulp chambber containing pulp

root of tooth is invested by a thin layer of cementum

Question 30

Dentin

Answer 30

composed of calcified organic matrix similar to bone

contains inorganic components in its matrix, calcium hydroxyapatite crystals

dentinal tubules, parallel tubes that radiate to the periphery of dentin

Question 31

Enamel

Answer 31

Translucent substance composed of parallel enamel rods (prisms) of calcium hydroxyapatite

rods are cemented together by an almost equally clcified interprismic material

Question 32

Cementum

Answer 32

amorphous calcified tissue (calcium hydroxyapatitie) into whichthe PDL is anchored

covers the dentin in the root

thicker towards the apex of the root

Question 33

Pulp

Answer 33

consists of loose, mesenchymal CT

collagen fibers, fibroblasts mesnechymal stem cells

highly vascular and well innervated

provides nutrition to the dentin and can form reactive dentin due to chronic injury

Question 34

Periodontium

Answer 34

Consists of cementum, peridontal ligament, alveolar bone, and gingiva

the peridontal ligament inserts into the cementum and alveolar bone that lines the alveolus and is comprised of collagen fibers