Pulp

Question 1

diameter of apical foramen in adult mandibular and maxillary teeth
:

Answer 1

maxillary :0.4mm

mandibular:0.3

Question 2

what are the most distinctive cells in pulp?

Answer 2

odontoblasts

Question 3

where are the odontoblasts in pulp found ?

Answer 3

in the odontoblastic zone which is found along the pulpal periphery

Question 4

what is the layer below the odontoblastic layer in pulp? what does it contain ?

Answer 4

cell free zone or zone of weil which contain capillaries and unmyelinated nerve fibers

40 microns

Question 5

what is the 3rd deepest layer of pulp , what does it contain?

Answer 5

cell rich zone. it consits mainly of fibroblasts , macrophages , lymphocytes , and dendritic cells. it also has undifferentiated ectomesenchymal cells

Question 6

what is the most common cell in pulp?

Answer 6

fibroblasts, particularly in coronal portion of pulp (cell rich zone)

Question 7

what is the deepest layer of pulp? what does it consist of?

Answer 7

pulp core. it consists of loose connective tissue , large vessels and nerves .

it also contains fibroblasts and pulpal cells as well as undifferentiated ectomesenchymal cells

Question 8

what is the main connective tissue of pulp?

Answer 8

loose connective tissue

Question 9

tome’s fiber is devoid of any cell organelles except:

Answer 9

microfilaments

Question 10

describe the shape of odontoblasts in the coronal pulp , midportion , and apical region

Answer 10

coronal pulp: Largest , columnar

midportion: cuboidal

apical region : flattened

Question 11

what is responsible for exchange of ions and small molecules between odontoblasts ?

Answer 11

gap junctions , tight junctions and desmosomes

Question 12

explain the 3 life stages of odontoblasts :

Answer 12

1.)n active stage : cell shoes increase in endoplasmic reticulum , Golgi body and secretory vesicle activity

2.) resting non active stage : cells are flattened little cytoplasm condensed chromatic and decreased number of ER

3.) Transient stage : in between active and resting stages( seen only under electron microscope)

Question 13

what is the function of odontoblasts ?>

Answer 13

synthesis of collagenous organic matrix as well as non collagenous proteins

Question 14

what is the cell responsible for forming and maintaining the pulp matrix(collagen and ground substance )?

Answer 14

fibroblasts

Question 15

what cell is responsible for degradation and digestion of collagen ?

Answer 15

fibroblasts

Question 16

describe the appearance of fibroblasts :”

Answer 16

flattened spindle shaped cells with dense nuclei

Question 17

secretion of primary dentin occurs during which life stage of odontoblasts ?

Answer 17

active phase

Question 18

tertiary dentin is secreted at which life stage of odontoblasts ?

Answer 18

transient stage

Question 19

what is the ground substance of pulp and WHAT is their function ? which cell is responsible for secreting it ?

Answer 19

-glycosaminoglycan
-glyco-protein +water
–>act as medium for transport of nutrients from vasculature to cells and of metabolites from cells to vasculature

secreted by fibroblasts

Question 20

which types of collagen are present in the pulp?

Answer 20

type I and 3

Question 21

connective tissue cells of the pulp are derived from the___

Answer 21

undifferentiated ectomesenchymal cells

Question 22

undifferentiated ectomesenchymal cells are often related to blood vessels

Question 23

cell that appears as a large polyhedral cell possessing large , lighly stained centrally placed nucleus :

Answer 23

undifferentiated ectomesenchymal cells

Question 24

how are the undifferentiated ectomeshencymal cells affected as pulp gets older?

Answer 24

their number and ability to differentiate comes down

Question 25

which type of lymphocyte is most common in pulp?

Answer 25

T lymphocytes

Question 26

dendritic cells are derived from ___

where are they found ?

Answer 26

bone marrow

found around the odontoblastic layer

Question 27

branched parietal layer of nerves present underneath the odontogenic layer is called___

Answer 27

sub-odontoblastic plexus of rashkow

Question 28

sensory afferent fibers are branches of ____

Answer 28

maxillary and mandibular division of trigeminal nerve

Question 29

which nerve fibers are myelinated and cause fast sharp pain when stimulated ?

Answer 29

A-delta fibers

Question 30

where are the A-delta fibers most commonly found ?

Answer 30

coronal (odontoblastic ) area of pulp

Question 31

which nerve fibers within the pulp are unmyelinated and cause a slow dull pain that is more diffuse in nature when stimulated ?

Answer 31

C-fibers

Question 32

where are C fibers most commonly found ?

Answer 32

in the central region of the pulp

Question 33

stimulation of which fibers results in vasoconstriction ?

Answer 33

sympathetic fibers (there is no para-sympathetic innervation in pulp)

Question 34

where are the sympathetic fibers of the pulp found?

Answer 34

deeper within the pulp

Question 35

discrete calcified masses in pulp are known as :

Answer 35

pulp stones

Question 36

what are the symptoms of pulp stones?

Answer 36

they are asymptomatic unless they impinge on blood vessels or nerve fibers

Question 37

what is the differnece between true denticles (pulp stones ) and false denticles ?

Answer 37

true denticels are similar in structure to dentin. they contain dentinal tubules and tome’s fiber. they also originate from hertwigs epithelial root sheath reminants in the pulp

false denticles do not contain dentinal tubules. they are formed around remenants of necrotic tissue or blood vessels

Question 38

denticles are most commonly seen :

Answer 38

close to the apical foramen

Question 39

what causes the development of true denticles ?

Answer 39

they are caused by the inclusion of remenant of the epithelial root sheath within the pulp, which induce the cells of the pulp to differentiate into odontoblasts

Question 40

relationship of denticles with age ?

Answer 40

as age increase , size and number of denticles also increase

Question 41

what are diffuse calcifications ?

Answer 41

dystrophic calsifications in pulp tissue following collagenous fiber bundles or blood vessels

Question 42

diffuse calcifiactions most often occur in ___

Answer 42

root canal , and less often in coronal pulp