Page 537 - Atlas of Histology with Functional Correlations

Digestive System Part I: Oral Cavity and

Salivary Glands

OVERVIEW

Hollow tube consisting of oral cavity, esophagus, stomach, small intestine,
large intestine, rectum, and anal canal
Salivary glands, liver, and pancreas are accessory organs located outside the

tube
Secretory products from all accessory organs delivered to the tube via
excretory ducts

ORAL CAVITY

Lined with stratified squamous epithelium for protection
Food masticated here, and saliva lubricates food for swallowing

Lips

Lined with thin skin covered by stratified squamous keratinized epithelium
Blood vessels close to the surface impart red color

Contain hairs, sebaceous and sweat glands, and mucus-secreting labial glands
Core contains skeletal muscle orbicularis oris

Tongue

Consists of connective tissue and interlacing skeleton muscle fibers
Dorsal surface divided into anterior two thirds and posterior third by sulcus
terminalis

Dorsal surface covered by elevations called filiform, fungiform, and
circumvallate papillae
Filiform papillae are most numerous, smallest, and keratinized; lack taste

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