Ten-Cate Flashcards
What type of collagen is primarily found in bone, cementum and dentin?
Type 1
Does enamel contain collagen?
No
What is more brittle: dentin or enamel?
Enamel
What are the two main types of cementum? Where are they located?
Cellular and acellular. Acellular (primary) is found in the upper (cervical) area of the root and the cellular (secondary cementum) is found in the lower (apical) portion.
What is Ca10(PO4)6(OH)2
Calcium Hydroxyapatite
What ions can substitute the calcium ion (in Ca10(PO4)6(OH)2)?
Magnesium and sodium
What can substitute the hydroxyl position (in Ca10(PO4)6(OH)2)?
Fluoride and chloride
Where can carbonate substitute (in Ca10(PO4)6(OH)2)?
In the hydroxyl and phosphate position
What does fluoride substitution in Ca10(PO4)6(OH)2 do to the crystals?
Decreases solubility of the crystals
What does Chloride substitution do in Ca10(PO4)6(OH)2 to the crystals?
Increases solubility of the crystals
What does magnesium do to crystal growth?
Inhibits crystal growth
What type of collagen primarily makes up cartilage?
Type II
To prevent enamel demineralization, should the oral environment be acidic, basic or neutral?
Neutral
Masticatory mucosa (palatal and gingival) has what layer tightly bound to the bone?
The neural tube and notocord are formed from:
A: Ectoderm
B: Mesoderm
C: Endoderm
A: Ectoderm
True or False:
Salivary glands, enamel, tonsils and dentin, bones (including the skull) are all derived from the surface ectoderm.
False.
Ectomesenchyme, bones, skull, dentin, PL and alveolar bone – are all derrived from the NEURAL CREST CELLS.
Salivary glands, and enamell are derived from SURFACE ECTODERM
Epithelium of the GI tract, pharynx and tonsils are all derived from ENDODERM.
True or false:
The proper migration of NEURAL CREST CELLS is essential for the development of the craniofacial skeleton and the teeth.
TRUE
Meckel’s cartilage forms the _______ and is derived from what?
Lower jaw.
Meckel’s cartilage is the cartilage of the first brachial arch.
What is the cartilage of the second brachial arch called?
What does it give rise to?
Reichert’s cartilage. It gives rise to a bony process, the stylohyoid ligament and the upper part of the body and lesser horns of the hyoid bone
What does the cartilage of the third brachial arch give rise to?
The fourth?
Third –> lower part of the body and greater horns of the hyoid bnoe
Fourth –> cartilage of the larynx
State from which arch the following is derived:
Muscles of mastication
Muscles of facial expression
Trigeminal nerve (CNV)
Facial Nerve (CNVII)
Glossopharyngeal nerve (CNIX)
Vagus nerve (CNX)
First arch –>Muscles of mastication
Second arch –> Muscles of facial expression
First arch –> Trigeminal n. (CNV)
Second arch –> Facial n. (CNVII)
Third arch –> Glossopharyngeal n. (CNIX)
Fourth arch –> Vagus n. (CNX)
Note – Aortic arch vessels (1 - 4 aorti arch branches correspond to the brachial arch 1-4)
List the 5 prominences of the face and what they form into.
Frontonasal prominence –> forehead, bridge of nose, and lateral nasal prominences
Maxillary prominence –> cheeks, lateral portion of the upper lip
Medial nasal prominence –> philtrum, creast and tip of nse
Lateral nasal prominence –> outer part of the nose
Mandibular prominence –> lower lip and lower jaw
What prominences form the upper lip?
What happens if these do not fuse properly?
The maxillary prominence and the medial nasal prominence fuse and end up forming the upper lip.
If do not fuse properly, result is a cleft lip.
What forms the primary palate?
The fusion of the medial nasal prominences
During development of the maxilla, what is the pattern of bone formation?
Intramembranous bone deposition
What cells secrete type I collagen (that make up the bulk of the gingival connective tissues)
Fibroblasts.
Odontoblasts and osteoblasts also produce type I collagen.
What type of cell maintains the contiguous peridontal tissues?
Fibroblasts
List the collegen fibers in gingiva.
Transseptal
Circular
Dento-gingival
Gingival-periosteal
dento-periosteal
What are INTEGRINS?
They are transmembrane adhesion molecules and act as matrix receptors and connect the matrix to the cytoskeleton. They help integrate cell adhesion and cell signalling processes and transfer forces from the extracellular matrix to the cytosekeleton.
What is made up of actin microfilaments, vimentin, intermediate filaments and tubulin-based microtubules?
The cytoskeleton of fibroblasts
True or false;
The high rate of collegen turnover by fibroblasts is important to maintain the normal cellular architecture and functio of the periodontium
True
What produces Elastin?
Fibroblasts and smooth muscle cells.
What are proteoglycans?
What synthesizes these?
Macromolecules that make up ground substance of the extracellular matrix.
- They are involved in adhesion and signalling.
- They are highly hydrated for regulating tissue hydration, diffusion of nutrients, waste products, etc.
- The two main macromolecules are PROTEOGLYCANS and GLYCOPROTEINS
The macromolecules are made by FIBROBLASTS.
What are proteoglycans?
A large group of extracellular and cell surface associated molecules that consist of a PROTEIN CORE which GLYCOSAMINOGLYCAN chains are attached.
Glycosaminoglycans consist of a combination of hexosamine and uronic acid.
Glycosaminoglycans are ACIDIC = NEGATIVELY CHARGED.
Are glycosaminoglycans:
Acidic or basic?
Do they bind readily or poorly to proteins?
Are they hydrophilic or hydrophobic?
Glycosaminoglycans are ACIDIC, bind READILY TO PROTEINS, and are HYDROPHILIC so bind to large amounts of water.
Hyluronic acid is a ___________________
GLYCOSAMINOGLYCAN (long chain of repeating disaccharide units consisting of a hexosamine and uronic acid).
Are fibroblasts involved in inflammation?
How?
Yes. They respond to stimulation such as inflmmation.
WHen stimulated, they release growth fators cytokines and inflammatory mediators.
MMPs degrade what?
Collagen. They are a family of PROTEOLYTIC ENZYMES
What is the resting membrane potential for most cells?
-70mV
How are the two types of local anesthetic agents removed?
Esters are by local hydrolysis
Amides are by removal through the bloodstream and metabolized in the liver.
List the common excitory neurotransmitters.
List the inhibitory neurotransmitters.
Excitatory:
glutamate
acetylcholine
norepinepherine
Inhbitory
GABA (gamma amino butyric acid)
Glycine
True or false:
GABA inhibits the neuroneuronal synapse by creating a hyperpolarization of the POSTSYNAPTIC membrane - generating an INHIBITORY postsynaptic potential. It does this by allowing Chloride into the cell or Potassium out of the cell. Resulting in reduced responsiveness.
What is the excitability threshold level of neurons?
-57mV
What is the effect of the following anesthetic agents on the neurons?
Benzodiazepines
Barbituates
Propofol
Isoflurane and Sevoflurane
These are all GABA agnonists (hyperpolarize cell = make it less negative and less close to the depolarization level (-57mV)):
Benzodiazepines - increases the frequency of channel opening
Barbituates - increases the duration tof time that the channel is open
Propofol - potentiates GABAergic synapes but slows the channel closing time (may also block sodium channel)
Isoflurane and Sevoflurane - increasing uptake of glutamate at excitatory synapses by glial cells
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