Goal 6 (c-f): Histology Of The Oral Cavity

Question 1

What type of epithelium does the oral cavity have?

Answer 1

Stratified squamous keratinized epithelium

Question 2

What 3 types of mucosa does the oral cavity have?

Answer 2

• masticatory: gums and hard palate
• specialized mucosa: dorsal surface of tongue, libidinal papillae
• lining mucosa: rest of oral cavity, stratified squamous nonketatinized epithelium

Question 3

What tissue is the skin aspect of the lip made of? What does it contain? Where is the vermilion region and why is it the color it is? Why does the oral mucosa region have a wet surface?

Answer 3

• stratified squamous keratinized epithelium
• thin skin with hair follicles, sebaceous and sweat glands
• bound by skin by the vermilion border (slight elevation of lip); pink reddish color because of how vascular it is, no glands here
• have mucous salivary glands- saliva makes it wet

Question 4

What type of epithelium is the dorsal part of tongue made of? Ventral part? Which part have the taste buds? What directions can the anterior 2/3 of the tongue move? What is on the posterior 1/3rds of the tongue that are aggregations of lymphocytes?

Answer 4

• specialized mucosa
• lining mucosa
• dorsal has taste buds, as well as liguinal papillae and lingual tonsils
• longitudinal, transverse, and oblique
• lingual tonsils

Question 5

Where do you find the lingual papillae?

Answer 5

Dorsal surface of tongue, anterior to the sulcus terminalis

Question 6

What is filiform papillae? Fungiform? Foliate? Circumvallate?

Answer 6

• filiform: most numerous, cone shaped, NO TASTE BUDS, stratified keratinized squamous
• fungiform: common near tongue tip, mushroom shaped, few taste buds, stratified squamous nonkeratinized
• foliate: posterior lateral on anterior 2/3rd of tongue, shallow furrows, has taste buds for 2 years and then the buds die, Von Ebner glands secrete into these furrows
• circumvallate: anterior to sulcus terminalis, a lot of taste buds, surrounded by deep moat like depression, least common papillae

Question 7

Which lingual papillae have taste buds? Why is it only this one?

Answer 7

• circumvallate

- a part of the tongue needs to be rough to maintain oral hygiene

Question 8

How to taste buds look like? What is a taste pore? What are the main 3 cell types found in taste buds?

Answer 8

• oval, pale stained bodies that extend through epithelium
• taste pore: small opening into the surface at the apex of the taste bud
• gustatory: have microvilli that project through taste pore, does the actual tasting
• supporting cells: thought to help gustatory cells
• basal cells: stem cells for the two above cells, needed for example when you burn your tongue to regenerate the cells lost

Question 9

What nerves innervate the tongue for taste?

Answer 9

CN 7, 9, 10

Question 10

What are the two types of salivary glands?

Answer 10

Acini and ducts

Question 11

What is the basic secretory unit of any salivary gland?

Answer 11

Salivon

Question 12

Describe the 3 types of Acini.

Answer 12

• serous acini: Spherical, have serous cells
• mucus acini: tubular, have mucus cells
• mixed acini: have both types of cells

Question 13

Describe the 3 types of ducts.

Answer 13

• intercalated ducts: simple cuboidal epithelium
• striated ducts: circular, white in color, lined with dark dots of mitchochondria
• excretory ducts: stratified cuboidal/columnar

Question 14

Does saliva go through ducts or acini first?

Answer 14

Saliva comes from acini as primary and leave ducts as secondary after the ducts modify the saliva

Question 15

Describe parotid glands.

Answer 15

• major salivary glands
• SEROUS ONLY (dark purple with granules microscopically)
• have a lot of adipose tissue around (appears as white circles)

Question 16

Describe submandibular glands.

Answer 16

• MOSTLY SEROUS(appear as dark purple spots), but see mucus/mixed (appear as lighter purple spots) too
• see striated ducts(appear pale in color)

Question 17

Describe sublingual glands.

Answer 17

• MIXED(see a mix of dark purple spots and light purple spots)
• will also see pale striated ducts

Question 18

What are the 4 layers of the GI tracts from deep to superficial and what do each contain?

Answer 18

• mucosa: epithelium, lamina propria, muscularis mucosa
• submucosa: meissner’s plexus
• muscularis propria: circular muscle, Auerbach’s or myenteric plexus, longitudinal muscle
• serosa or adventitia

Question 19

Which layer contains a part that has loose connective tissue, a lot of blood vessels, and lymphocytes?

Answer 19

Lamina propria, located in the mucosa layer

Question 20

Which layer allows movement and motility of the GI tract?

Answer 20

Muscularis Mucosa

Question 21

What is the difference between adventitia and serosa?

Answer 21

• adventitia: thin sheet of CT rich in vessels, lymphatic, adipose and surrounds tissues
• serosa- similar but is covered with a simple squamous layer instead

Question 22

What will happens without the nerve plexuses?

Answer 22

• problem with motility and dilutions in some areas of the GI tract
• example: Hirshprungs and Chages Disease

Question 23

What two areas of the GIT have stratified non keratinized squamous epithelium? Which have stratified keratinized squamous? What has simple cuboidal?What type of epithelium does the rest of the GIT have?

Answer 23

• non: esophagus and anal valves
• keratin: anus
• cuboidal: proximal to anal valves
• rest have simple columnar

Question 24

What layer of the GIT have Brunner’s glands in their submucosa?

Answer 24

Duodenum

Question 25

Where in the GIT are there Peyer’s patches in their submucosa?

Answer 25

Ileum