Tongue & Salivary Glands

Question 1

Tongue Structures

Answer 1

• Epiglottis
• Lingual and Palatine Tonsils
• Sulcus Terminalis (anterior/posterior)
• Lingual Papillae (4 types)
• Median Sulcus (left/right)

Question 2

Tongue Composition

Answer 2

Oral Mucosa
Stratified Squamous Epithelium
Connective Tissue
Skeletal Muscle (Oblique, Transverse, Longitudinal)

Question 3

4 Types of Papillae

Answer 3

Filiform - cone, keratinized, grip, no taste buds
Fungiform - dome, apical taste buds
Foliate - flat top, moats, lateral (2 side) taste buds
Circumvallate - dome, lingual glands, lateral taste buds

Question 4

Taste Buds Structure

Answer 4

Taste Pore
Sensory Receptor Cell with microvilli (detect tastant)
Supporting Cell (precursors)
Basal Stem Cell
Afferent Nerve Terminal (send signal)

Question 5

Taste Bud Activation

Answer 5

• tastant binds to taste receptor cell (GPCR)
• Gα dissociate, bind to GTP, open ion channel, ion enter
• depolarize membrane
• release NT onto synapse

Question 6

3 Major Salivary Glands

Answer 6

• only secrete when signal
  Parotid Gland = into parotid duct
  Submandibular Gland = into submandibular duct
  Sublingual Gland = into mouth

Question 7

Structure of Salivary Glands

Answer 7

Merocrine
Compound tubulo-acinar

Question 8

Major Components and Function of Saliva

Answer 8

Buffer Oral Cavity: bicarbonate raise pH
Food Breakdown: amylase –> starch, lipase –> fats
Bacterial Growth: lysozyme (wall), IgA (immune), Lactoferrin (remove iron)
Moisten Food: water
Tooth Mineralization: Ca2+/K+ = protect enamel
Protective Film on Teeth: proteins

Question 9

Structure of Saliva Secretion

Answer 9

Salivary Gland Acinus
- secretory cells release components into duct
- NaCl and H2O from capillaries
Intercalated Duct
Striated Duct
- produce bicarbonate
- resorb NaCl

Question 10

Inside a Lobule –> Lobe

Answer 10

Acinus (secretory units)
Intercalated Duct/Intralobular (low cuboidal epithelium)
Striated Duct/Intralobular (simple cuboidal epithelium)

Excretory Duct/Interlobular
Lobar Duct

Question 11

3 Types of Secretion

Answer 11

Serous Acinus: water+proteins = Paratoid gland
- dark cytoplasm, round basal nuclei, distinct lumen

Mucous Acinus: gel+glycoprotein = Sublingual gland
- light cytoplasm, flat basal nuclei

Mixed Acinus: serous+mucous = Submandibular gland
- serous demilune on top of mucous acinus

Question 12

Striated Duct

Answer 12

• round central nuclei + basal striations
• basal plasma membrane infolding (regulate saliva)
• parallel mitochondria (resorb NaCl)

Question 13

Myoepithelial Cells

Answer 13

• surround all acini (stellate shape)
• contract = squeeze serous and mucus acini to release saliva into duct