DENT410 POB
POB
POB
Oct 10, 2014. EXTRACELLULAR MATRIX (collagen, elastin, proteoglycans). Dr. Clive Roberts. Fibroblasts lay down ____ , and can differentiate into which 4 types of cells?
cartilage.
bone cells, fats cells, cartilage cell, and smooth muscle cells.
how is matrix gene expression influenced?
1. adherence to the matrix influences gene expression
2. mechanical stresses in matrix influence gene expression
3. matrix binds biologically active molecules (eg. chemokines) that have signalling properties.
which two receptors do cells use to interact with the matrix?
1. integrins (high affinity adhesion)
2. CD44 (hyaluronan receptor) - low affinity adhesion, often used in migration
periodontal ligament (PDL) contains which types of connective tissue?
draw a diagram of the stress strain relationship of the three types of connective tissue . what does the slope in such a diagram mean?
the steeper the slope, the stiffer the material.
*tendon is representative of collagen, while cartilage is representative of proteoglycan
collagen is organized in the form of _____ _____, with 1/3 of _____ residues to form the inner core, a high content of ________ to form kinks, and ____________ to form H-bonds
triple helix;
glycine
proline
hydroxyproline
abnormal collagen formation will result in which 3 types of diseases?
dermatosparaxis ,OI (genetic) and scurvy (nutritional)
describe how scurvy arises.
1. ascorbate is needed in redox cycling of iron in proline hydroxylase
2. proline hydroxylase contains iron, and it hydrolizes proline to hydroxyproline
3. hydroxyproline is necessary for proper collagen triple helix structure
*scurvy is caused by the lack of ascorbic acid in the diet
there are 4 different types of collagens (I,II,III,IV) , where are these types found?
type I,III are found in skin
type II is found in cartilage
type III is found in blood vessels
type IV is found in basal laminae
mnemonic: type I is the strongest, type IV is the weakest ,
therefore , type ONE forms bONE and skin and dentin
type TWO forms only carTWOlage
elastin has a high content of _______ amino acids. ____ forms the meshwork on which elastin fibers are assembled. Improper meshwork will cause a disease called _______ syndrome. The enzyme _______ ______ forms ______ crosslinks between elastin fibers, and improper functioning of this enzyme will result in the disease called ______ disease
hydrophobic .
Fibrillin
Marfan syndrome
lysyl oxidase; COVALENT
menkes disease
The meshwork of proteoglycans is __________ . Proteoglycans are glycoproteins that contain the polysaccharide ________________. Why is the negative charge on this polysaccharide is important to the function of proteoglycans?
Collagen
Glycosaminoglycans (GAGs)
The negative charge is important becaues it attracts positively charged ions like Ca, K , and Na.
Most importantly, it creates an osmotic swelling pressure to the proteoglycan, and this osmotic pressure causing to structure to expand is counter-balanced by the collagen meshwork, which bounds the proteoglycan.
Aggrecan is the "aggregating " ________ of cartilage. It is a monomer of ____ proteins with primarily ____ ____ glycosylation. It aggregates cartilage by forming polymers with ________ and ___proteins.
proteoglycan.
250k
chondroitin sulphate
hyaluronan and link proteins
SEPT26, 2014. DEVELOPMENT AND STRUCTURE OF DENTIN AND ENAMEL. DR. CLIVE ROBERTS. PDL and sub-endothelial matrix both have ____, ____, and _______.
collagen, elastin, proteoglycan
dentin (odontoblast) and enamel (ameloblast) formation: describe this process briefly
1. epithelial cells induce papilla mesenchymal cells to become differentiated odontoblasts
2. the underlying papilla mesenchymal cells induce the overlying epithelial to become ameloblasts.
* the stellate reticulum provides ions for the developing enamel cells
(dentin formation must always occur before enamel formation)
The first layer of dentin formed from odontoblasts is called ____ ____
mantle dentin
Root dentin formation involves ______ ______ _____ _____ and proceeds for __ years after eruption.
Hertwig's Epithelial Root Sheath (HERS) and proceeds for 3 years after eruption
enamel formation: the _______ of hydroxyapatite gives the crystals a starting place to grow.
nucleation
abacus bodies are only found in ________________
odontoblasts
the process of mineralization occurs in the :
mineralization occurs in collagen-proteoglycan matrices except in _____. Briefly describe the steps of mineralization.
enamel.
Teeth / bone has a lot of hydroxyapatite (mineral form of CaPO4)
1. Ca2+ is bound by osteocalcin (a pro-osteoblastic protein) and sialoproteins
2. ECM phosphate concentration is increased by Alkaline phosphate, an enzyme secreted by ameloblasts/odontoblasts/osteoblasts that release phosphates from molecules into the ECM.
3. CaPO4 crystallizes , maturing to its mineral form hydroxyapatite
distinguish the difference between primary, secondary and tertiary dentin
primary: most of the tooth
secondary dentin: deposited with age, especially in the roof and floor of molars
tertiary dentin: dentin formed as a reaction to external stimuli, such as cavities. It can be reactionary (dentin formed from pre-existing odontoblasts), or reparative (dentin formed from new odontoblasts that replaced dead ones).
reparative dentin is aka SCLEROTIC dentin
define the following terms:
mantle dentin
circumpulpal dentin
pertibular dentin
sclerotic dentin
mantle dentin: very first layer made by odontoblasts under the epithelial cells
circumpulpal dentin: dentin around the pulp
peritubular dentin: dentin around the dentin tubules; has more minerals
sclerotic dentin: dentin formed as a result of reparative mechanisms (dentin formed by new odontoblasts that replace the dead ones)
____ mineralized enamel is more translucent, while ____ mineralized enamel is more opaque.
more mineralized, more translucent
less mineralized , more opaque
the formation of enamel is divided into the _____ and the ______ phase. What does each phase involve?
secretory and maturation phase.
secretory phase involves production of a 30% mineralized matrix
maturation phase involves removal of organic material , and mineral goes up to 95%
in enamel formation, ameloblasts contribute 5 types of proteins, what are they?
Amelogenin
Ameloblastin
Enamelin
Enamelysin
Kallikrein 4
Explain the function of amelogenin, ameloblastin, and enamelysin. Describe mutations to these proteins
amelogenin forms 'jelly' in vitro. Mutations lead to hypoplastic enamel lacking rods
Ameloblastin is involved in cell matrix interaction with enamel synthesis. Mutations cause ameloblasts to detach from the cell matrix.
Enamelysin: proteinase that 'trims' enamel, esp. in adults. Mutations lead to poorly structured enamel.
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Flashcards
Oct 10, 2014. EXTRACELLULAR MATRIX (collagen, elastin, proteoglycans). Dr. Clive Roberts. Fibroblasts lay down ____ , and can differentiate into which 4 types of cells?
cartilage.
bone cells, fats cells, cartilage cell, and smooth muscle cells.
how is matrix gene expression influenced?
1. adherence to the matrix influences gene expression
2. mechanical stresses in matrix influence gene expression
3. matrix binds biologically active molecules (eg. chemokines) that have signalling properties.
which two receptors do cells use to interact with the matrix?
1. integrins (high affinity adhesion)
2. CD44 (hyaluronan receptor) - low affinity adhesion, often used in migration
periodontal ligament (PDL) contains which types of connective tissue?
draw a diagram of the stress strain relationship of the three types of connective tissue . what does the slope in such a diagram mean?
the steeper the slope, the stiffer the material.
*tendon is representative of collagen, while cartilage is representative of proteoglycan
collagen is organized in the form of _____ _____, with 1/3 of _____ residues to form the inner core, a high content of ________ to form kinks, and ____________ to form H-bonds
triple helix;
glycine
proline
hydroxyproline
abnormal collagen formation will result in which 3 types of diseases?
dermatosparaxis ,OI (genetic) and scurvy (nutritional)
describe how scurvy arises.
1. ascorbate is needed in redox cycling of iron in proline hydroxylase
2. proline hydroxylase contains iron, and it hydrolizes proline to hydroxyproline
3. hydroxyproline is necessary for proper collagen triple helix structure
*scurvy is caused by the lack of ascorbic acid in the diet
there are 4 different types of collagens (I,II,III,IV) , where are these types found?
type I,III are found in skin
type II is found in cartilage
type III is found in blood vessels
type IV is found in basal laminae
mnemonic: type I is the strongest, type IV is the weakest ,
therefore , type ONE forms bONE and skin and dentin
type TWO forms only carTWOlage
elastin has a high content of _______ amino acids. ____ forms the meshwork on which elastin fibers are assembled. Improper meshwork will cause a disease called _______ syndrome. The enzyme _______ ______ forms ______ crosslinks between elastin fibers, and improper functioning of this enzyme will result in the disease called ______ disease
hydrophobic .
Fibrillin
Marfan syndrome
lysyl oxidase; COVALENT
menkes disease
The meshwork of proteoglycans is __________ . Proteoglycans are glycoproteins that contain the polysaccharide ________________. Why is the negative charge on this polysaccharide is important to the function of proteoglycans?
Collagen
Glycosaminoglycans (GAGs)
The negative charge is important becaues it attracts positively charged ions like Ca, K , and Na.
Most importantly, it creates an osmotic swelling pressure to the proteoglycan, and this osmotic pressure causing to structure to expand is counter-balanced by the collagen meshwork, which bounds the proteoglycan.
Aggrecan is the "aggregating " ________ of cartilage. It is a monomer of ____ proteins with primarily ____ ____ glycosylation. It aggregates cartilage by forming polymers with ________ and ___proteins.
proteoglycan.
250k
chondroitin sulphate
hyaluronan and link proteins
SEPT26, 2014. DEVELOPMENT AND STRUCTURE OF DENTIN AND ENAMEL. DR. CLIVE ROBERTS. PDL and sub-endothelial matrix both have ____, ____, and _______.
collagen, elastin, proteoglycan
dentin (odontoblast) and enamel (ameloblast) formation: describe this process briefly
1. epithelial cells induce papilla mesenchymal cells to become differentiated odontoblasts
2. the underlying papilla mesenchymal cells induce the overlying epithelial to become ameloblasts.
* the stellate reticulum provides ions for the developing enamel cells
(dentin formation must always occur before enamel formation)
The first layer of dentin formed from odontoblasts is called ____ ____
mantle dentin
Root dentin formation involves ______ ______ _____ _____ and proceeds for __ years after eruption.
Hertwig's Epithelial Root Sheath (HERS) and proceeds for 3 years after eruption
enamel formation: the _______ of hydroxyapatite gives the crystals a starting place to grow.
nucleation
abacus bodies are only found in ________________
odontoblasts
the process of mineralization occurs in the :
mineralization occurs in collagen-proteoglycan matrices except in _____. Briefly describe the steps of mineralization.
enamel.
Teeth / bone has a lot of hydroxyapatite (mineral form of CaPO4)
1. Ca2+ is bound by osteocalcin (a pro-osteoblastic protein) and sialoproteins
2. ECM phosphate concentration is increased by Alkaline phosphate, an enzyme secreted by ameloblasts/odontoblasts/osteoblasts that release phosphates from molecules into the ECM.
3. CaPO4 crystallizes , maturing to its mineral form hydroxyapatite
distinguish the difference between primary, secondary and tertiary dentin
primary: most of the tooth
secondary dentin: deposited with age, especially in the roof and floor of molars
tertiary dentin: dentin formed as a reaction to external stimuli, such as cavities. It can be reactionary (dentin formed from pre-existing odontoblasts), or reparative (dentin formed from new odontoblasts that replaced dead ones).
reparative dentin is aka SCLEROTIC dentin
define the following terms:
mantle dentin
circumpulpal dentin
pertibular dentin
sclerotic dentin
mantle dentin: very first layer made by odontoblasts under the epithelial cells
circumpulpal dentin: dentin around the pulp
peritubular dentin: dentin around the dentin tubules; has more minerals
sclerotic dentin: dentin formed as a result of reparative mechanisms (dentin formed by new odontoblasts that replace the dead ones)
____ mineralized enamel is more translucent, while ____ mineralized enamel is more opaque.
more mineralized, more translucent
less mineralized , more opaque
the formation of enamel is divided into the _____ and the ______ phase. What does each phase involve?
secretory and maturation phase.
secretory phase involves production of a 30% mineralized matrix
maturation phase involves removal of organic material , and mineral goes up to 95%
in enamel formation, ameloblasts contribute 5 types of proteins, what are they?
Amelogenin
Ameloblastin
Enamelin
Enamelysin
Kallikrein 4
Explain the function of amelogenin, ameloblastin, and enamelysin. Describe mutations to these proteins
amelogenin forms 'jelly' in vitro. Mutations lead to hypoplastic enamel lacking rods
Ameloblastin is involved in cell matrix interaction with enamel synthesis. Mutations cause ameloblasts to detach from the cell matrix.
Enamelysin: proteinase that 'trims' enamel, esp. in adults. Mutations lead to poorly structured enamel.
