Saliva˖°𓇼🌊⋆🐚🫧

Question 1

saliva is a mixture that contains 3 pairs of major salivary glands list them______

Answer 1

parotid gland
submandibular gland
sublingual gland

Question 2

along the major salivary glands we have other glands situated beneath the oral mucosa________

Answer 2

minor salivary glands

Question 3

saliva contains other constituents list them

Answer 3

GCF (gingival crevicular fluid ) from gingival sulcus

microbial contaminants ex, bacteria , toxins etc

desquamated epithelial cells which are dead cells from oral mucosa that eventually shed into saliva

Question 4

saliva composition

Answer 4

mainly water , inorganic, nonprotein organic compounds , and proteins

Ions in saliva Important for Buffering & Remineralization

also K+ and Na+

Question 5

why is K + more in saliva and less in plasma , Na+ more in plasma and less in saliva

Answer 5

the sodium is actively resorbed by salivary glands as it moves through ducts esp. the striated ducts resulting into more sodium in plasma now for potassium its the opp. salivary glands secrete it into the ducts sooo more in saliva btw this whole exchange is how primary isotonic saliva become final hypotonic saliva(˶˃ ᵕ ˂˶)

Question 6

functions of saliva

Answer 6

lubricates our oral cavity making it easy to swallow⭑.ᐟ

water balance how?(ᵕ—ᴗ—) well ..
(🧂 Na⁺ reabsorbed in ducts, 🚫💧 water stays
🧪 Saliva becomes hypotonic (less salty)
🥵 Dehydration → ↓ saliva → 😖 dry mouth
💧 Triggers thirst → makes you drink! 🥤
🛡️ Helps conserve body water )

antimicrobial action by lysozyme, lactoferrin , IgA and IgG

digestion by amylase which is an enzyme in bacteria

saliva acts as a solvent for chemicals in food this helps stimulating taste receptors 🐻‍❄️ྀིྀི

minor role in excretion by excreting small amounts of waste ex urea, ammonia and heavy metals

remineralization by forming an acquired enamel pellicle which is protein layer on surface of tooth , ion reservoir , buffer

mechanical cleansing

aggregates and clears away microorganism

lastly saliva contains buffering agents which neutralize acid in plaque ( helps to buffer PH changes in plaque)

Question 7

why is saliva considered a wonderful biomarker to know if there is a systemic disease

Answer 7

due to its rich mixture of substances
we can know if there is oral cancer , DM and esp. we use saliva to know if there is AIDS also helps in knowing hepatitis B and C ( ˶°ㅁ°) !!

Question 8

minor salivary glands are located where

Answer 8

Labial mucosa (lips)

Buccal mucosa (cheeks)

Tongue (especially the base)

Hard palate (posterior part)

Soft palate

Question 9

histology of major salivary glands

Answer 9

classified as compound tubuloacinar glands branching network of **ducts **with secretory units clustered at end called **acini **which secrete saliva into **lumen **then saliva moves into intercalated ducts

Question 10

describe serous secretions

Answer 10

low viscosity and rich in protein

Question 11

describe mucous secretions

Answer 11

high viscosity and rich in carbohydrates

Question 12

secretory epithelial cells can form two types of clusters

Answer 12

circular or tubular

Question 13

secretory epithelial cells sit on what

Answer 13

basement membrane

Question 14

what’s the role of the delicate CT that surrounds BM

Answer 14

provides nutrients, blood supply , O2 to epithelial cells

Question 15

structure of salivary gland

Answer 15

surrounded by capsule where CT septa divides it into lobes where its further divided into lobules where the acini and ducts are

Question 16

3 types of secretory units

Answer 16

• serous
  -mucous
• mixed which is mucous with serous demilune ( serous cells that sit on top of mucous acini looking like half moon hence the name demilune)

Question 17

serous acini histologically

Answer 17

intensely staining cells due to the protein
got a central lumen and basement membrane that is surrounded by delicate CT

Question 18

mucous acini histologically

Answer 18

pale staining cells cuz of mucin ( glycoproteins with lots of carbohydrates/sugar preventing it from picking up the stain)
nucleus is at the base
got also basement membrane surrounded by delicate CT

Question 19

mixed acini histology

Answer 19

the main part is tubular cluster of mucous cells and on top is serous demilune where its fine cell processes extend into lumen

Question 20

serous cells produce what

Answer 20

protein and polysaccharides

Question 21

mucous cells produce what

Answer 21

mucinogen

Question 22

if we look inside the serous cell we can see

Answer 22

apex is acidophilic - has dark stained granules ( protein rich vesicles )

basal part is basophilic - basal prominent nucleus

organelles for synthesis of proteins

they will add amylase, some IgA and glycoproteins to saliva

Question 23

if we look inside mucous cell we can see

Answer 23

basal prominent nucleus

organelles to produce CHO

secretion mainly protein sugar complex called mucin

mucous and seromucous will add some IgA , lysozyme and some lactoferrin

Question 24

myoepithelial cells role

Answer 24

they are specialized epithelial cells located btw the secretory cells and their BM , octopus like due to their cytoplasmic processes around the acini and intercalated ducts

they expel and contract due to the actin filaments , allows expansion of the acinar cells to store and contract to force it out into lumen

Question 25

myoepithelial cells under light microscope

Answer 25

spindle shaped nuclei that can obvious but acidophilic cytoplasm tend to blend with CT

Question 26

ductal system

Answer 26

structure and function depends on the glands whether major or minor ductal wall made of epithelial cells and type of epithelium varies along transports , ion and fluid exchange modification of saliva

Question 27

intercalated duct

Answer 27

short and directly connected to acini lined by short cuboidal epithelial cells prominent in parotid gland join striated duct

Question 28

both intercalated and striated ducts are what kind of ducts

Answer 28

Intralobular ducts (within a lobule)

Question 29

striated duct

Answer 29

main ion exchange site larger than intercalated low columnar epithelial cells with basal striations in EM those basal striations look like plasma infoldings filled with mitochondria for NA+/K+ pump resorbing sodium and secreting K ,bicarbonate and phosphate buffers

Question 30

if we have low flow rate of saliva

Answer 30

more time for ion exchange so more hypotonic saliva

Question 31

if we have high flow rate of saliva

Answer 31

less time for ion exchange so isotonic

Question 32

interlobular excretory ducts

Answer 32

larger than striated large lumen near striated pseudostratified columnar sometimes with mucous goblet and as we go towards oral cavity becomes stratified columnar then stratified squamous nonkeratinized epithelium collects saliva and transport it to oral cavity

Question 33

main excretory ducts

Answer 33

stratified squamous non keratinized epi they modify a little not like striated by resorbing Na+ and secreting K+ and mucous empties into oral cavity

Question 34

what surrounds the parenchyma (acini and ducts) basically entire salivary gland

Answer 34

CT stroma

Question 35

what is stroma made of

Answer 35

fibrous CT includes capsule and septa( branches of CT that divide gland into lobes and lobules) provides blood supply ,nerve supply and physical support

Question 36

nerve supply in salivary gland

Answer 36

autonomic ( para and symp)

Question 37

parasympathetic stimulation

Answer 37

triggered by taste and smell causes vasodilation( more blood flow into acini and ducts) leading to water serous saliva production

Question 38

sympathetic stimulation

Answer 38

viscous mucous secretion

Question 39

why is major salivary glands discontinuous

Answer 39

cuz its stimulated by taste , smell , chewing

Question 40

parotid gland

Answer 40

serous acini eosinophilic in H and E stain sections intralobular adipose tissue at higher magnification serous cells contain intracellular zymogen granules

Question 41

submandibular gland

Answer 41

mixed but more serous than mucous ofc its mucous with serous demilune got also adipocytes

Question 42

sublingual gland

Answer 42

mucous large secretory ducts also adipocytes

Question 43

minor salivary glands

Answer 43

over 600 mainly mucous lack true capsule its circumscribed ( loosely surrounded by CT) known as accessory glands

Question 44

architecture of minor salivary glands

Answer 44

small , scattered clusters unlike major glands which are one large encapsulated gland made of tiny lobules and may share a common excretory ducts or have their own opening into oral cavity continuous secretion so no need for neural control )⊹ ࣪ ﹏𓊝﹏𓂁﹏⊹ ࣪ ˖

Question 45

embryology of salivary glands

Answer 45

origin: primitive oral ectoderm invagination: starts in weeks 6-7 bud formation : epithelial buds into underlying mesenchyme then divides and branch forming spherical cells end of cord : secretory acini proximal part : duct CT : capsule and septa develop from surrounding mesenchyme not ectoderm

Question 46

as we age what changes

Answer 46

less cells more fibers / CT more adipocytes saliva production decreases hence hyposalivation , dental caries , oral diseases

Question 47

clinical considerations

Answer 47

infections viral: mumps ( parotid commonly affected) bacterial due poor hygiene or duct blockage sialolithiasis ( salivary stones) tumors of glands autoimmune diseases: Sjogren syndrome