The Digestive System (I) - The Oropharyngeal Tissues

Question 1

Describe the concept of “torus”

Answer 1

a doughnut like geometric form analogous to the body tissues - stretched to a tubular shape

Question 2

What muscle encircles the lips?

Answer 2

orbicularis oris

aids in closing, retaining closure while chewing, speaking, sucking, kissing, etc.

Question 3

What three parts can the labia be divided into?

Answer 3

(Lips)
- the cutaneous area
- the red area (vermillion)
- the oral mucosa

Question 4

Describe the cutaneous area of the labia.

Answer 4

“the mustache region” - has hair follicles as well as sebaceous glands and sweat glands

covered by keratinized stratified squamous epidermis

Question 5

Describe the red area (vermillion) of the labia.

Answer 5

“the lipstick region” - a hairless region where the two lips meet - dermal papillae are particularly high here allowing blood capillaries and nerve endings to come close to the surface of the skin

capillaries of this region result in the “red” hue and the nerve endings make this the most sensitive region of the lip

usually no glands but sometimes a few sparse sebaceous glands

Question 6

Describe the oral mucosa of the labia.

Answer 6

the inner surface of the lip - facing the teeth and gums

• nonkeratinized stratified squamous epithelium with numerous labial glands* (mucous and seromucous)

*some have only serous acini and some have mixed acini of both serous and mucous cells

Question 7

What structure is located at the top of the mouth?

Answer 7

the palate

this structure serves as a horizontal septum between the oral and nasal cavities

• maintains airflow while chewing

Question 8

What two regions can the palate be divided into?

Answer 8

• the hard palate
• the soft palate

Question 9

What organ serves food manipulation and speech? What types of muscles enable this movement?

Answer 9

the tongue

intrinsic muscles - within the tongue
extrinsic muscles - connect the tongue to the hyoid bone, mandible, temporal bone, and other structures of the chin, throat, and skull

Question 10

What parts can the regions of the tongue be divided into?

Answer 10

the body - anterior 2/3 of the tongue - having lingual papillae (filiform, foliate, and fungiform)

the root - the posterior 1/3 of the tongue - having lingual tonsils and glands

the terminal sulcus - a groove separating the body and the root of the tongue immediately anterior to the row (V-Shaped) of vallate papillae

Question 11

What is the general name given to the glands embedded into the tongue?

Answer 11

Lingual Glands

Question 12

Describe the differentiation of the glands of von Ebner.

Answer 12

these are the posterior serous lingual glands seen in the vicinity of vallate papillae

these glands have ducts that lead into the trenches of the vallate papillae

these glands supply antibodies, lysozomes, and saliva flushing out the trenches of the vallate papilla, removing old food, dissolving chemicals = the taste buds remain receptive and responsive to new taste molecules

Question 13

Aside from the glands of von Ebner, where do other lingual glands such as the ventral glands aid in function?

Answer 13

short ducts open onto the ventral (inferior) surface of the tongue

Question 14

Where do dorsal glands reside? What other structures do they aid?

Answer 14

ducts in the root of the tongue lead to the dorsal (superior) surface of the tongue - emptying into the crypts of the lingual tonsils as well as the spaces between the lingual tonsils.

Question 15

Which of these structures in the salivary gland has a cap-like substructure called a demilune?

Answer 15

Mixed acini

Question 16

What are the two types of Acini?

Answer 16

Serous - dense, filled with zymogen granules (secretory vesicles) – produce a watery, enzyme rich secretion

Mucous - light stain, large lumen, filled with mucin droplets – produce mucous secretions - often having serous demilunes

Question 17

Describe the Parotid Gland.

Answer 17

anterior to the auricle of the ear - relative composed of adipose and entirely serous in humans

Question 18

Describe the Submandibular Gland.

Answer 18

medial to the mandible - mainly serous with some mucous acini which have serous demilunes

Question 19

Describe the Sublingual Glands.

Answer 19

in the floor of the mouth - multiple ducts - mainly mucous acini with numerous large serous demilunes, with few serous acini

Question 20

What are the 5 regions of a tooth?

Answer 20

1. Clinical Crown
2. Anatomical Crown
3. Gingival Crevice
4. Cervix
5. Root

Question 21

What are the 4 main components that compose a tooth

Answer 21

1. Enamel
2. Dentin
3. Cementum
4. Pulp

Question 22

What secretes enamel?

Answer 22

Ameloblasts

Question 23

What are the main characteristics of Dentin?

Answer 23

• true tissue
• not as hard as enamel - forming bulk of tooth, lending strength
• capable of regeneration

** Formed by odontoblasts in the pulp cavity

Question 24

What part of the tooth shrinks with age? Why?

Answer 24

The pulp cavity shrinks with age as odontoblasts retreat and secrete dentin in their place

Question 25

What is the process of tooth formation named?

Answer 25

Odontogenesis

Question 26

What are the stages of Odontogenesis?

Answer 26

1. Dental Lamina Stage
2. Bud Stage
3. Cap Stage
4. Bell Stage
5. Apposition Stage

Question 27

What differentiation occurs in the Cap Stage?

Answer 27

bud transforms into a cap-shaped structure with an
- outer enamel epithelium
- inner enamel epithelium
- middle stellate epithelium

Question 28

What characteristic distinguishes the Bell Stage from other stages of tooth development?

Answer 28

Dental Papilla