Histology of oral cavity, salivary glands etc

Question 1

____ lines the oral cavity

Answer 1

Oral mucosa

Question 2

Name the three types of oral mucosa, what they contain and where they are located

Answer 2

1) Masticatory mucosa- contains stratified squamous keratinized/Para-keratinized epithelium. Found in gums and hard palate
2) Specialized mucosa- contains lingual papillae. Found on dorsal surface of tongue
3) Lining mucosa: contains stratified squamous non-keratinized epithelium. Found in the remaining parts of the oral cavity

Question 3

Name the three regions of the lip

Answer 3

Cutaneous region, Vermillion region, & Oral mucosa region

Question 4

_____ region is covered by thin skin with hair follicles, sweat glands and sebaceous glands

Answer 4

Cutaneous

Question 5

Why is the vermillion region called the “red region”?

Answer 5

Due to the connective tissue containing blood vessels

Question 6

True or false: There are no glands in the vermillion region so it becomes dry

Answer 6

True

Question 7

____ region is the wet surface of the lip

Answer 7

oral mucosa region

Question 8

The anterior 2/3 of the tongue consist of a core mass of _____ that is oriented in 3 directions: ___, ____, & ___.

Answer 8

skeletal muscle
longitudinal, transverse, & oblique

Question 9

The posterior 1/3 (posterior to the sulcus terminalis)
displays the _____.

Answer 9

Lingual tonsils

Question 10

The taste buds in the _____ papillae are only seen in the first 2 years of life and then disappear

Answer 10

Foliate

Question 11

What are taste buds?

Answer 11

they appear as oval, pale-staining bodies that extend through the thickness of the epithelium

Question 12

A small opening onto the epithelial surface at the apex
of the taste bud is called the _____

Answer 12

taste pore

Question 13

Name the 3 principal cell types found in taste buds

Answer 13

gustatory cells, supporting cells , & basal cells

Question 14

What is the function of basal cells?

Answer 14

Acts as the stem cells for the gustatory and supporting cells

Question 15

What is the basic secretory unit of any salivary gland?

Answer 15

Salivon

Question 16

What does salivon consist of?

Answer 16

Acinus, intercalated duct and excretory duct

Question 17

Acini are spherical, containing ____ cells (protein secreting); more tubular, containing ____ cells (mucin-secreting); or ____, with both types of cells

Answer 17

Serous, Mucus, Mixed

Question 18

What type of cells are present at the base of secretory cells?

Answer 18

Myoepithelial

Question 19

_____ cells have flat nucleus towards base of cell, appears columnar, has thick secretions and a large lumen

Answer 19

Mucus

Question 20

Secretion from acinus is drained by the ____ duct

Answer 20

Intercalated

Question 21

The intercalated duct merges into the ____ duct and finally into the ____ duct.

Answer 21

Striated & excretory

Question 22

Which acini does the parotid gland contain?

Answer 22

Serous (ONLY)

Question 23

Which acini does the submandibular gland contain?

Answer 23

Predominantly serous but also mucous/mixed acini

Question 24

What is alimentary canal composed of?

Answer 24

1) Mucosa
2) Submucosa
3) Muscularis Propria
4) Serosa/ Adventitia

Question 25

What makes up the mucosa membrane?

Answer 25

-Epithelial lining (E); * Lamina propria (LP), a layer of of loose connective tissue rich in blood vessels, lymphatics, lymphocytes, smooth muscle cells, and often containing small glands; * Muscularis mucosae (MM), a thin layer of smooth muscle separating mucosa from submucosa and allowing local movements of the mucosa

Question 26

What does the submucosa contain?

Answer 26

It contains connective tissue with larger blood and lymph vessels and the submucosal (Meissner) plexus of autonomic nerves

Question 27

What does the musculosa/muscularis externa contain?

Answer 27

two layers of smooth muscle: internal sublayer- fiber is generally circular -external sublayer - fiber is longitudinal The connective tissue between the muscle sublayers contains blood and lymph vessels, as well as the myenteric (Auerbach) nerve plexus

Question 28

What does the serosa/ adventitia contain?

Answer 28

-Adventitia, a thin sheet of loose connective tissue, rich in blood vessels, lymphatics, and adipose tissue, and is continuous with that of surrounding tissues. - Serosa, is similar to adventitia, but covered with a simple squamous covering epithelium (mesothelium)

Question 29

What happens if the nerve plexuses in the GI are absent/damaged?

Answer 29

* Disturbance in the motility and dilations in some areas of the GIT * In diseases such as Hirschsprung disease, plexuses in the digestive tract’s enteric nervous system are absent or severely injured

Question 30

_____ is formed of many autonomic neurons interconnected by pre- and post-ganglionic nerve fibers

Answer 30

Nerve Plexus

Question 31

What are the 4 layers of the GI tract that are seen in the Esophagus

Answer 31

Mucosa, Submucosa, esophageal glands, and muscularis externa

Question 32

What happens at the esophagogastric junction?

Answer 32

Abrupt change in epithelium

Question 33

What secretes additional neutral mucus to protect the esophagus from regurgitated gastric contents?

Answer 33

esophageal cardiac glands