Teeth and Pancreas

Question 1

Which cells are involved in the formation of enamel and where are they located?

Answer 1

ameloblasts- located on dentin during tooth development.

Question 2

What proteins are secreted during the formation of enamel?

Answer 2

Amelogenin (90%) and enamelin.

Question 3

What happens to most of the proteins after they are secreted in tooth development?

Answer 3

They are mineralized by Ca and P.

Question 4

What is the main component of enamel?

Answer 4

Calcium and phosphate crystals.

Question 5

What is the structure and orientation of enamel rods?

Answer 5

Highly organized prisms.

Each rod is produced by an ameloblast.

Question 6

Which cells are involved in the formation of dentin and where are they located?

Answer 6

Odontoblasts- located in pulp cavity, and produce predentin (unmineralized matrix).

Question 7

What is difference between detin and predentin?

Answer 7

Predentin- Unmineralized organic matrix

Dentin- Mineralized

Question 8

What makes up dentin?

Answer 8

• Type I collagen
• Ground substance (glycosaminoglycans)
• Hydroxyapatite crystals (more than bone, so harder than bone)

Question 9

Describe the formation, structure, location and function of odontoblastic processes:

Answer 9

Formed: by odontoblast retreat
Structure: sting-like
Location: Dentinal tubule
Function: transmit stimuli from tooth surface to nerve.

Question 10

Describe the components of tooth pulp:

Answer 10

• Blood vessels
• Collagen
• Fibroblasts
• Immune cells
• Odontoblasts
• Pain nerve fibers

Question 11

How does the tooth stay in the socket?

Answer 11

Peridontium- tissues involved in attachment of tooth to bone.

Question 12

Which section of gingina contains stratified squamous keratinized?

Answer 12

Free gingiva.

Question 13

Which sections of gingiva contain non-keratinized stratified squamous?

Answer 13

Sulcular epithelium- not firmly attached.

JE- firmly attached.

Question 14

What helps join the JE to the tooth?
A. Desmosomes
B. Hemidesmosomes

Answer 14

B. Hemidesmosomes

Question 15

Describe the location and structure of cementum:

Answer 15

Surrounds dentin in the root area of the tooth.
Similar to bone.
Made by cementoblasts.

Question 16

Which cells in the periodontal ligament produce the ground substance and type I collagen fibers?
A. Osteoblasts
B. Osteoclasts
C. Cementoblasts
D. Fibroblasts
E. Immune cells

Answer 16

D. Fibroblasts

Question 17

Besides connecting bone to cementum, what are the other functions of the PDL?

Answer 17

• Shock absorber
• Sensory (nerve endings)
• Nutritive function (blood supply)
• Remodeling function (mesenchymal cells differentiate)

Question 18

PDL structure:

Answer 18

Connects alveolar bone to cementum via Sharpey’s fibers (type I collagen).

Question 19

What is the role of the blood supply and nerve endings in the periodontal ligament?

Answer 19

Nutrition

Sensory

Question 20

Describe the general organizational structure of the pancreas:

Answer 20

• Capsule surrounding lobules with many septa (CT) running through it.
• Contains blood vessels and interlobular ducts.

Question 21

How can you tell the difference between a vein, artery and duct?

Answer 21

Ducts- cuboidal, stain darker.

A/V- Simple squamous

Question 22

Are pancreatic acini the endocrine or exocrine part of the pancreas?

Answer 22

Exocrine- secrete their substances into a duct.

Question 23

What do centroacinar cells secrete and where are they located?

Answer 23

Located in an acinus near the intercalated duct.

Secrete bicarb.

Question 24

What are the secretions of pancreatic acinar glands?

Answer 24

Bicarb 
Zymogen granules (inactive protease)- prevents digestion of cellular proteins.

Question 25

How can you positively identify a section as endocrine pancreas?

Answer 25

Islets of Langerhans

Question 26

What are the other digestive enzymes secreted by the pancreas?

Answer 26

• lipase (lipids)

- amylase (carbs)