Upper GIT

Upper GIT

1. Oral Cavity

   • Mucosa
     • Epithelium
       • stratified squamous non-keratinized epithelium or partially keratinized epithelium in the:
         • gingiva
         • dorsal surface of tongue
         • hard palate
           • the mucosa is directly adherent to the periosteum of the bone
     • Lamina propria
       • loose areolar connective tissue
   • Submucosa
     •  contains minor salivary glands

2. Lip

   • The outer surface of the lip is covered by skin
     • stratified squamous keratinized epithelium with skin appendages (hair follicles, sebaceous glands and sweat glands).
   • The red margin or (Vermilion zone )
     • Partially keratinized stratified squamous epithelium
     • Abundant blood capillaries
     • Abundant sensory nerve endings
   • The inner surface is covered by mucosa
     • stratified squamous non-keratinized epithelium.
     • The lamina propria contains groups of mucous glands called:
       • labial glands
   • The main bulk of the lip is formed of bundles of skeletal muscle fibers of orbicularis oris muscle running around the mouth through the lips.

3. Tongue

   • The tongue consists of a mass of criss-crossing striated muscle bundles covered by mucous membrane
   • The muscle bundles are arranged in 3 directions: transverse, longitudinal and vertical
   • The mucous membrane of the lower surface of the tongue is smooth
   • The dorsal surface of the tongue is divided by the v-shaped terminal sulcus into anterior two thirds and a posterior one third
     • the anterior two thirds is coated by a great number of small projections called:
       • lingual papillae.
     • The posterior third shows small bulges composed mainly of aggregations of lymphoid nodules called:
       • lingual tonsils
   • Lingual (mucous) glands are found in the connective tissue corium of the posterior part of tongue
   • Tongue Papillae
     • 3) Circumvallate papillae
     • 4) Foliate papillae
     • 2) Fungiform papillae
     • 1) Filiform papillae

Images and files in the map