Page 539 - Atlas of Histology with Functional Correlations

Teeth

Developing teeth found in dental alveolus in the jawbone
Downward growth from oral epithelium forms dental lamina and gives rise to
ameloblasts
Mesenchyme gives rise to dental papilla and odontoblasts

Odontoblasts secrete dentin, whereas ameloblasts produce enamel of tooth

MAJOR SALIVARY GLANDS

Parotid, submandibular, and sublingual are major salivary glands that
produce saliva
Composed of secretory acini and excretory ducts that bring saliva into oral

cavity
Cells are serous or mucous; serous cells form serous demilunes around
mucous acini
Contractile myoepithelial cells surround serous and mucous acini and part of

intercalated ducts
Serous, mucous, and mixed secretory acini empty secretions into intercalated
ducts
Intercalated ducts merge into larger striated ducts with basal membrane

infoldings
Striated ducts form larger interlobular ducts that empty into interlobar
excretory ducts
Glands produce about 1 L of saliva per day, which is mostly water

Saliva formed after autonomic stimulation
Saliva contains electrolytes and carbohydrate-digesting enzyme salivary
amylase
Saliva contains antibodies produced by plasma cells and lysozyme to control

oral bacteria
Saliva is modified by transport of ions as it passes intercalated ducts and
striated ducts
Striated ducts absorb sodium and chloride from saliva, whereas potassium

and bicarbonate ions are added to produce hypotonic saliva

Review Questions

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