Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Oral Histology > Enamel Tissue > Flashcards

Enamel Tissue Flashcards

1
Q

Which tissue is the hardest of the 4 mineralized tissues of the body?

A

enamel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Of the 4 tissues of a tooth, which is the only that is NOT a connective tissue?

A

enamel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Enamel is derived from what tissue?

A

ectodermal derived tissued formed by a specialized epithelial cell - ameloblasts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Of the 4 mineralized tissues, enamel is the only one that does not have an ___ or ___ formation stage.

A

unmineralized; preenamel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

T/F. Enamel has a immature stage (partially mineralized) and a mature stage (fully mineralized).

A

True.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

T/F. The ameloblast completes its enamel formative cycle once the thickness of enamel is reached at a site (most advanced coronally).

A

True.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Enamel is the ___ mineralized tissue to appear in a developing tooth, ___ is the first to appear.

A

second; dentin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

T/F. Enamel is not subjected to malformations (genetic and external factors), age changes, and self-induced habits.

A

False, Enamel IS subjected to malformations (genetic and external factors), age changes, and self-induced habits.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

T/F. Enamel does not have enclosed cells (acellular), nerves (aneural), blood vessels (avascular), or lymph vessels (alymphatic).

A

True.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Which tissue is the most clinically significant?

A

enamel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the value for enamel on the Mohs mineral hardness scale?

A

5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Enamel can withstand ___ and impact forces well but is ___ without dentin support.

A

shearing; brittle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Enamel appears ___ and its hue depends on location, surface conditions of enamel, attraction to stain substances, and ages changes.

A

translucent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

T/F. Enamel does NOT need a wet environment to maintain its integrity.

A

False. Enamel DOES need a wet environment to maintain its integrity.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Define attrition.

A

Normal, slow wearing away of tooth substances under the stress of mastication.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Are abrasion and erosion normal or not normal?

A

not normal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

___ are pathways for diffusion of small molecules, such as water, and ___ effects on pore walls lead to carious lesions.

A

Microporosity; electrochemical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

In ___, mineral is returned to the molecular structure of enamel by way of the ___. When this is exceeded by demineralization, ___ occurs.

A

remineralization; saliva; caviation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the inorganic substance that makes up 96% by weight of enamel?

A

hydroxyapatite crystals. compared to the other 3 mineralized tissues they are larger and consist of more impurities (fluoride, carbonate).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the principal mineral component?

A

calcium hydroxyapatite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How much (by weight) does the organic substance make up of enamel?

A

1%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the main protein found in enamel?

A

amelogenin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How are the organic enamel proteins arranged?

A

in a lace-like pattern throughout the volume of enamel and closely associated with the surface of the crystals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

T/F. Enamel contains collagen fibers.

A

False, enamel does not contain collagen fibers.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
How is water distributed throughout enamel?
by way of micropores between crystals and proteins
26
Most water forms a ___ ___ around each crystal.
hydration shell
27
Which CEJ relationship is most, next and least common?
most: cementum overlaps enamel next: cementum meets enamel least: cementum does not met enamel (causes pain)
28
Which cell has columnar epithelial cells?
ameloblasts
29
What is another name for the growth lines of enamel?
Lines or Strae of Retzius
30
Define perikymata.
Numerous small transverse ridges on the exposed surfaces of enamel.
31
Explain the relationship between Lines of Retzius and perikymata?
Lines of Retzius end on the enamel surface as grooves, ridges (perikymata) are created between the grooves.
32
What is the structural unit of enamel?
enamel rods
33
A rod has a diameter of _-_um and a lenghth of up to ___mm. There are several ___ crystallites packed into each rod.
5-6; 2.5; million
34
Hydroxyapatite crystals are most dense in the ___ or ___ of the rod and run ___ to the long axis of the rod.
center; core; parallel
35
T/F. Each rod is formed by ONE ameloblast.
True.
36
What is the name for the outer surface of the rod?
enamel sheath
37
In the enamel sheath, crystals are ___ dense than the core and run in different directions. The highest percentage of organic material is ___.
less; amelin
38
What substance is found in the sheath of the rods?
interrod substance
39
Interrod substance is secreted from two or more ___ and its crystals are ___ dense and run at different directions than those of the sheath.
ameloblasts; more
40
What direction do enamel rods run in comparison to the dentin surface?
right angles
41
Each enamel ___ is built up of segments separated by dark lines that give it a striated appearance, hence the name ___ ___.
rods; interrod striations
42
Why are enamel rods striated?
because it is secreted in a rhythmic manner
43
The ___ period of an ameloblast is marked by an interrod striation.
rest
44
T/F. Under the microscope, enamel rods have a fish scale appearnce.
True.
45
What are three examples of HYPOmineralized enamel structures?
1. enamel lamella 2. enamel tuft 3. enamel spindle
46
Enamel lamellae, extend for varying depths from the surface of ___ and consist of longitudinally oriented defects filled with enamel ___ or organic debris from the ___ cavity.
enamel; protein; oral
47
What is the clinical significance of enamel lamella?
due to their access by acidophilic microorganisms (caries) and to stain substances (esthetic considerations)
48
Enamel ___ appear are ribbon-like structures that originate at the ___ surface and passes toward the ___. They may enter the dentin and pass into the ___.
lamella; enamel; dentin; pulp
49
What projects from the dentinoenamel junction for a short distance into enamel and contain greater concentrations of enamel protein (tuftelin)?
enamel tuft
50
What is the clinical significance of enamel tuft?
it contributes to the spread of caries at the DEJ
51
___ extend from the dentin across the ___ into the enamel for a short distance.
Spindles; DEJ
52
What is the clinical significance of enamel spindles?
they contribute to the spread of caries along the DEJ
53
Before the secretion of dentin and enamel begins, some cell processes of ___ extend between ___, and when enamel formation begins, the processes become embedded within the newly secreted enamel, resulting in the formation of the ___ ___.
odontoblasts; ameloblasts; enamel spindle
54
Match the following: A. Lamella B. Tuft C. Spindle I. originates at the DEJ and passes into enamel II. originates at enamel surface and passes inward III. originates in dentin and passes DEJ into enamel
A - II B- I C - III
55
What are alternating dark and light bands (layers) of varying width that originate at the DEJ border and pass outward ending at some distance from the outer enamel surface?
Hunter-Schreager bands
56
What causes Hunter - Schreager bands?
different directions of enamel rods in adjacent layers
57
What change in rod direction is regarded as a functional adaptation, minimizing the risk of cleavage in the axial direction under the influence of masticatory forces and is clinically significant when performing operative dentistry?
Hunter-Schreager bands
58
Where does differentiation of the inner epithelial cells of the enamel organ into ameloblasts and the peripheral cells of the dental papilla into odontoblast begin?
in the coronal most site of the future dentinoenamel junction
59
Ameloblast form partially mineralized or ___ enamel and move outward. ___ for predentin and move inward toward the center of the ___.
immature; Odontoblasts; pulp
60
What is an enamel pearl?
an ectopic enamel formation
61
Caries is formed from ___ enamel.
unsupported
62
Tetracycline staining and mulberry molars (cogenital syphilis) cause damage during what process?
odontogenesis
63
What does dens in dente mean?
tooth within a tooth

Oral Histology (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions