Histology of Taste and Olfaction

Question 1

What is the type of epithelium for the respiratory system?

What other cells does it possess?

Answer 1

Pseudostratified columnar ciliated epithelium.

Includes goblet cells and basal stem cells.

Question 2

What layer provides the blood supply to respiratory epithelium?

Answer 2

Lamina propria

Question 3

Nasal vestibule

Respiratory region

Olfactory region

Answer 3

Nasal vestibule: just inside the nostrils, lined by skin.

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

Olfactory region: located at apex (upper 1/3), lined by olfactory mucosa.

Question 4

Epithelium of nasal vestibule

Answer 4

Keratinized stratified squamous. It is skin.

Question 5

Olfactory mucosa epithelium:

Hallmarks (2):

What glands does it have?

Answer 5

Psuedostratified columnar epithelium.

Much thinner than respiratory epithelium. No goblet cells.

Olfactory glands

Question 6

Olfactory receptor cells

Answer 6

Specialized, nonmotile cilia w/ odorant receptors.

Have a single dendritic process.

Question 7

Basal cells of olfactory mucosa

Answer 7

Stem cells for olfactory receptor and supporting cells.

Question 8

Brush cells of olfactory mucosa epithlium:

What CN does it contact?

Answer 8

Ciliated columnar epithelium.

Contacts CN V.

Question 9

Supporting/sustentacular cells of olfactory mucosa function:

Answer 9

Provides mechanical and metabolic support the the olfactory receptor cells.

Question 10

Epithelium of oral cavity

What is the epithelium divided into? (3)

Answer 10

Stratified squamous type w/ varying keratinization and specialized mucosa.

Lining, masticatory and specialized mucosa.

Question 11

Papillary and dense layers of lamina propria

Answer 11

Papillary: superficial, loose CT w/ neurovasculature.

Dense: deep, dense CT w/ lots of fibers.

Question 12

Where is masticatory mucosa found?

What is the epithelium?

Answer 12

Hard palate, gingiva and dorsal surface of tongue.

Keratinized and/or parakeratinized startified squamous epithelium.

Question 13

Where is lining mucosa?

What is the epithelium? What are the layers of it?

Answer 13

Lips, cheeks, alveolar mucosa, floor of the mouth, inferior surface of tongue and soft palate.

Nonkertanized SS epithelium.

1. stratum basale: on lamina propria.
2. stratum spinosum: several layers thick.
3. stratum superficiale: superficial layers.

Question 14

Where is the specialized mucosa?

What does it contain? (2)

Answer 14

Only on dorsal tongue.

Papillae and taste buds.

Question 15

Tongue is composed of which mucosas? (2)

What epithelium covers the muscular surface of the tongue?

Answer 15

Masticatory and specialized mucosa.

Keratinized SS epithelium.

Question 16

Lingual papilla

Answer 16

Small elevated structures of mucosa that are associated w/ taste buds.

Question 17

Filiform papillae

Foliate and fungiform papillae

Circumvallate papillae

Answer 17

Move food toward pharynx. Velvety texture of tongue. No taste buds.

Involved in taste sensation.

Hundreds of taste buds.

Question 18

What shape are taste buds?

Answer 18

Barrel-shaped

Question 19

Neuroepithelium (sensory) cells of taste buds

What do they synapse with? (3)

Answer 19

Elongated cells from basal lamina that extend into taste pore.

CN VII, IX or X.

Question 20

Support cells of taste buds:

Basal cells of taste buds:

Answer 20

Cells from basal lamina to taste pore and do NOT synapse

Small cells on basal taste bud. Stem cells.

Question 21

Taste sensations and their location on tongue (w/ one excpetion) (5)

Answer 21

Sweet: tip of tongue.
Salt: anterior and lateral tip of tongue.
Sour: lateral margin of tongue.
Bitter: posterior tongue.
Umami (savory): taste of monosodium glutamate.

Question 22

Can taste buds register all 5 senses?

Where can we register all 5 senses?

Answer 22

Only 2/5.

Posterior pharynx and epiglottis.

Question 23

What is dentin made of?

What is dentinal tubules?

Answer 23

Ca++ hydroxyapatite.

Dentinal tubules radiate to periphery of dentin.

Question 24

What is enamel made of?

What holds it together?

Answer 24

Enamel rods of Ca++ hydroxyapaptite.

Held together by interprismatic material.

Question 25

Ameloblasts make:

Odontoblasts make:

Answer 25

Enamel

Dentin