Tooth, Tongue, Salivary Glands

Question 1

composition of teeth

Answer 1

internal soft tissue (pulp) and 3 calcified tissues: enamel and cementum (surface layer), and dentin (b/w surface layer and pulp)

Question 2

what are the calcified dental tissues made of?

Answer 2

calcium hydroxyappatite

Question 3

what is the crown covered by?

Answer 3

enamel

Question 4

what is the root covered by?

Answer 4

cementum

Question 5

what is the cervix?

Answer 5

region where the 2 surface materials meet

Question 6

composition of enamel

Answer 6

highly calcified matrix composed of 2 fibrous high MW glycoproteins - enamelin and amelogen

Question 7

what is enamel produced by?

Answer 7

ameloblasts during crown formation

Question 8

why do adults not produce more enamel?

Answer 8

no longer have active ameloblasts

Question 9

enamel after tooth eruption?

Answer 9

acellular - cannot repair itself

Question 10

what does dentin surround?

Answer 10

central pulp chamber and pulp (root) canal

Question 11

composition of dentin

Answer 11

calcified matrix containing collagen fibers

Question 12

production of dentin

Answer 12

made by odontoblasts, which remain and continue to produce dentin

Question 13

where are odontoblasts located?

Answer 13

periphery of pulp - send cytoplasmic extensions (odontoblastic processes) into tunnel-like spaces (dentinal tubules) w/i dentin

Question 14

how is any stimulation of the nerves in the pulp chamber interpreted?

Answer 14

as pain

Question 15

composition of cementum

Answer 15

collagen-containing calcified matrix

Question 16

what produces cementum?

Answer 16

cementoblasts

Question 17

what are cementocytes?

Answer 17

cells that send processes w/i canaliculi towards the periodontal ligament

Question 18

cellular cementum

Answer 18

apical region of cementum - contains cementocytes within lacunae

Question 19

acellular cementum

Answer 19

coronal region of cementum - NO cementocytes

Question 20

where are cementoblasts found?

Answer 20

both cellular and acellular cementum

Question 21

cementoblast function

Answer 21

continuously produce cementum after tooth eruption to compensate for the decrease in tooth length that results from enamel abrasion

Question 22

dental pulp composition

Answer 22

• gelatinous CT w/ odontoblasts in the peripheral layer (closest to dentin)
• fibroblasts
• mesenchymal cells
• thin collagen fibers

Question 23

describe blood supply of dental pulp

Answer 23

richly vascularized

Question 24

innervation of dental pulp

Answer 24

• sympathetic vasomotor - control blood vessel luminal diamenet
• sensory

Question 25

periodontal ligament

Answer 25

dental supporting structure - consists of dense irregular CT b/w root cementum and bony alveolus (alveolar bone proper)

Question 26

collagen fiber arrangement in periodontal ligament

Answer 26

principal fiber bundles - extend from cementum to bone and suspend tooth in its alveolus

Question 27

function of principal fiber bundles

Answer 27

absorb and counteract chewing forces

Question 28

describe perfusion and innervation of periodontal ligament

Answer 28

abundant nerve and vascular supply

Question 29

gingivae epithelium

Answer 29

stratified squamous parakeratinized to keratinized epithelium

Question 30

composition/arrangement of gingivae

Answer 30

- has dense irregular CT - collagen arranged in 5 principal fiber bundles - similar to periodontal ligament

Question 31

how does gingivae attach to enamel surface?

Answer 31

via hemidesmosomes

Question 32

alveolar bone composition

Answer 32

- inner layer = cribriform plate - outer layer of compact bone = cortical plate - intervening layer of trabecular bone = spongiosa

Question 33

what is the sulcus terminalis?

Answer 33

V-shaped depression that divides tongue into anterior 2/3 and posterior 1/3

Question 34

foramen cecum

Answer 34

shallow pit at the end of the apex of the sulcus terminalis

Question 35

covering of dorsal surface of tongue?

Answer 35

stratified squamous parakeratinized to keratinized epithelium

Question 36

covering of ventral surface of tongue?

Answer 36

stratified squamous nonkeratinized epithelium

Question 37

what do both ventral and dorsal surfaces of the tongue have?

Answer 37

lamina propria and submucosa of dense irregular collagenous CT

Question 38

what constitutes the bulk of lingual tissue?

Answer 38

muscular core

Question 39

where are lingual papillae located?

Answer 39

dorsal surface of anterior 2/3 of tongue

Question 40

four types of lingual papillae?

Answer 40

- filiform - fungiform - foliate - circumvallate

Question 41

filiform papillae

Answer 41

- short and narrow - highly keratinized - pointed - project above the tongue surface

Question 42

fungiform papillae

Answer 42

- mushroom shaped - project above tongue surface - interspersed among filiform papillae - occasionally have taste buds

Question 43

foliate papillae

Answer 43

- shallow - longitudinal furrows - located on tongue lateral aspect

Question 44

circumvallate papillae

Answer 44

- large and circular - each one surrounded by moat-like furrow - 10-15 total - distributed in V-pattern just anterior to sulcus terminalis

Question 45

taste buds

Answer 45

intraepithelial sensory organs - each consisting of 60-80 spindle-shaped cells

Question 46

four cell types in taste buds

Answer 46

- dark cell = type 1 - light cell = type 2 - intermediate cell = type 3 - basal cell = type 4

Question 47

average lifespan of cells in taste bud

Answer 47

10 days

Question 48

proposed relationship of cell types in taste buds

Answer 48

basal cells give rise to dark cells, which become light cells, which turn into intermediate cells, then die

Question 49

specialization of taste buds

Answer 49

each taste bud specializes in 2 of 4 tastes

Question 50

salte and sour tastes

Answer 50

due to specific ion channels in cells

Question 51

bitter and sweet tastes

Answer 51

due to specific membrane receptors

Question 52

what specific receptors detect bitter substances?

Answer 52

TAS2R

Question 53

what detects savory tastes? how?

Answer 53

umami - detects carboxylate ion on glutamic acid - monosodium glutamate

Question 54

what is loss of taste called?

Answer 54

ageusia

Question 55

what is partial loss of taste called?

Answer 55

dysgeusia

Question 56

what can cause partial or complete loss of taste?

Answer 56

infections, radiation treatment, chemicals, head injury

Question 57

function of lingual salivary glands?

Answer 57

minor salivary glands that deliver serous secretion into furrow surrounding each papilla and assist taste buds in perceiving stimuli

Question 58

what are the glands of von Ebner?

Answer 58

glands that secrete serous fluid with lipases into the groove by cirumvallate papillae

Question 59

composition of tongue muscular core

Answer 59

- bundles of skeletal muscle fibers which cross each other in 3 planes - numerous minor salivary glands interspersed

Question 60

3 paired exocrine glands that make up the salivary glands

Answer 60

parotid, submandibular, and sublingual

Question 61

parotid gland

Answer 61

- serous acini | - 28 grams

Question 62

submandibular gland

Answer 62

- serous and mucous acini - mixed | - 7-8 grams

Question 63

sublingual gland

Answer 63

- mainly mucous with serous demilunes | - 2 grams

Question 64

functions of salivary glands

Answer 64

make and secrete lysozyme, amylase, lactoferrin, and secretory component for IgA

Question 65

description of branching of salivary glands

Answer 65

compound tubuloalveolar - may be serous or mixed mucoserous

Question 66

composition of salivary glands

Answer 66

dense irregular CT capsule surrounds gland

Question 67

what divides salivary glands into lobes and lobules?

Answer 67

septa containing excretory ducts

Question 68

approximately how much saliva does an average person produce in a day?

Answer 68

1.5 L/day

Question 69

why do you not easily get infections when you get cuts in the mouth?

Answer 69

lysozome and lactoferrin in saliva = antibacterials

Question 70

salivary gland acini description

Answer 70

- serous and mucous cells arranged around a central lumen | - connects to intercalated duct

Question 71

where does the intercalated duct lead?

Answer 71

into striated, intralobular ducts

Question 72

what may intercalated duct cells secrete and absorb?

Answer 72

secrete bicarbonate and absorb chloride ions

Question 73

what may mucous acini have?

Answer 73

serous demilunes

Question 74

what aids in saliva secretion?

Answer 74

myoepithelial cells near basal lamina