GI Histology Master Atlas: Mucosa, Submucosa, Muscularis Externa, Serosa, Myenteric (Auerbach) & Meissner Plexus, Oral Mucosa vs Vermillion vs Cutaneous Lip, Filiform/Fungiform/Circumvallate/Foliate Papillae, Enamel/Ameloblasts, Dentin/Odontoblasts, Saliv

GI Histology Master Atlas: Mucosa, Submucosa, Muscularis Externa, Serosa, Myenteric (Auerbach) & Meissner Plexus, Oral Mucosa vs Vermillion vs Cutaneous Lip, Filiform/Fungiform/Circumvallate/Foliate Papillae, Enamel/Ameloblasts, Dentin/Odontoblasts, Salivary Glands (Parotid/Submandibular/Sublingual), Intercalated & Striated Ducts, Esophagus Muscle Layers, Z-Line, Gastric Pits (Parietal/Chief/G Cells), Rugae, Plicae Circulares, Villi & Crypts of Lieberkühn, Paneth Cells, Brunner’s Glands, Peyer’s Patches, Teniae Coli, Portal Triad, Hepatic Sinusoids, Kupffer & Ito Cells, Space of Disse, Zones 1–3, Bile Canaliculi, Cholangiocytes, Pancreatic Acini & Centroacinar Cells Exam Questions Verified and Complete with A+ Graded Rationales Latest Updated 2026 What are the 4 main layers of the GI tract? mucosa (inner most) submucosa muscularis serosa (outer most) Where is the myenteric plexus located? Between the inner circular and outer longitudinal muscular layers of the muscularis externa What are the plexuses of the enteric nervous system? Meissner Myenteric (auerbach) auerbach's plexus histology Nerve plexus between two muscular layers - between inner circular and outer longitudinal muscle layers What are the three parts of the lips? oral mucosa vermillion skin Oral mucosa histology of the lip nonkeratinized stratified squamous epithelium - with underlying lamina propria and submucosa - minor salivary glands (bottom of this image) vermillion of the lip Between the oral part and skin part of the lips with stratified squamous epithelium (nonkeratinized or lightly keratinized) - no glands - no hair follicles - VERY RED (lots of blood vessels here) cutaneous surface (skin) histology of the lip keratinized stratified squamous with HAIR FOLLICLES, sebaceous glands, and sweat glands (right side on image) Which oral surface has no keratin? oral mucosa (bottom of image) Masticatory mucosa mucosa of the gingiva and the hard palate - keratinized (slightly) - stratified squamous epithelium mucosa = _____ + _____ epithelium + lamina propria Where are minor salivary glands found? submucosa throughout the oral cavity Tongue epithelium stratified squamous (nonkeratinized) EXCEPT for keratinized filiform papillae 4 types of tongue papillae filiform (NO TASTEBUDS) fungiform vallate foliate What part of the tongue is keratinized? filiform papillae filiform papillae keratinized cone shaped papillae NO TASTE BUDS - helps move food around the mouth **most abundant** What papillae has no taste buds? filiform papillae fungiform papillae Mushroom like papillae - found near the tip of tongue HAS TASTEBUDS **looks like red spots scattered on the tongue** filiform = ______ color fungiform = _______ color filiform = whitish/gray appearance fungiform = red spot appearance circumvallate papillae large papillae WITH taste buds at the back of tongue - line up in a row ** have serous glands of Von Ebner that flush out their crypts/furrows** Which taste buds have furrows with Von Ebner serous glands? circumvallate papillae