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WVSOM -- Histology
Gastrointestinal System
Question | Answer |
---|---|
What is in the oral cavity? | Mucosa Submucosa Lips Tongue Taste buds |
What makes up the mucosa of the oral cavity? | stratified squamous nonkeratinized epithelium and a lamina propra of loose connective tissue |
What is the core of the lips | Skeletal muscle called orbicularis oris |
What is the orbicularis ors? | skeletal muscle core of the lips |
What is the outer surface of the lips? | It is lined with skin |
Histological features of the tongue (6) | stratified squamous keratinized epithelium Papillae Skeltal Muscle Serous and mucus glands Glands of Von Ebner Taste buds |
Inner surface of the lips | oral muscoa with labial glands in the lamina propria |
Papillae of the tongue | Contain receptors for taste |
Gland of Von ebner | Serous glands of the oral cavity Wash out the taste buds |
Filiform paillae | elongated and partially keratinized cover the dorsal surface of the anterior 2/3 of the tongue |
Fungiform papillae | mushroom-shpaed Scattered over the dorsal surface of teh tounge and contain taste buds |
(Circum)vallate papillae | lie along the sulcus terminalis that divides the anterior 2/3 of the tongue. Extremely large and surrounded by a groove, or oat. Empty their secretions into teh moat around the papilla have taste buds |
Waldeyer's Ring | An interrupted circle of protective lymphoid tissue at the upper ends of the respiratory and alimentary tracts |
Lingual Tonsil | diffuse infiltration of lymphocytes or multiple small nodules. Below epithelium of the posterior third of the tongue |
Layers of the tooth | Ameloblasts enamil Dentin Odontoblasts papilla |
Crown of tooth | projects above the gingiva |
Gingiva | mucous membrane that is attached to teh alveolar periosteum and surrounds teh neck of the tooth |
root of the tooth | projects below the gingiva |
Pulp | core of the tooth that is made up of loose connective tissue |
Pulp cavity | contains the pulp |
Dentin | Calcified tissue that covers the pulp |
Dentin is made up of | odontoblasts |
Dentin growth | formation continues through life |
What part of the tooth gets smaller | pulp cavity |
Enamel | covers the dentin on the crown of teh tooth. Hardest surface in the body |
Enamel is made up of | ameloblasts |
Where are ameloblasts? | cover the surface of the developing tooth |
General organization of the digestive tract | From inside out: Mucosa Submucosa Muscularis externa Serosa |
Mucosa of the GI tract | epithelium (simple squamous or cuboid) Lamina Protpria Muscularis mucosa |
Muscularis mucosa | smooth muscle that can contract under the sympathetic nervous system |
Submucosa | Below the mucosa Dense irregular connective tissue Contains meissner's plexus |
Muscularis externa | moves the food toward the anal canal big ring of muscle |
Serosa (adventitia) | layer of loose connective tissue which is not covered by a mesothelial covering (visceral peritoneum) Mesothelium Connective tissue |
Histological Features of the Esophagus (4) | Stratified squamous non-keratinized epithelium Skeletal muscle (top 1/3 and mixed in middle 1/3) Smooth muscle (bottom 1/3 and mixed in the middle 1/3) Serous-mucus glands in the submucosa |
Layers of esophagus | Lumen Epithelium Lamina propria muscularis mucosa muscularis externa |
Mucosa of esophagus | epithelium + lamina propria + muscularis mucosa |
What glands are found in lamina propria of esophagus? | mucus-secreting esophageal cardiag glands |
Muscularis mucosa is a | single longitudinal layer of smooth muscle |
Submucosa of the esophagus | esophageal glands (serous) Muscularis externa |
Muscularis externa of esophagus | skeletal in upper third smooth and skeletal in middle third smooth muscle in lower third |
Histological features of the stomach (3) | Cardiac Fundic Pyloric |
Body of stomach | fundus |
Cardiac glands of the stomach | mucous cells that secrete mucus and lysozyme |
lysozyme | bacteriocidal enzyme |
Gastric glands | Found in fundus of stomach. |
Cell types of gastric glands | undifferentiated stem cells mucous neck cells parietal cells chief cells enteroendrocrine cells |
Lamina propria of stomach | has gastric pits on surface of epithelium into the lamina propria. Lined with mucous cells Gastric glands |
Gastric Glands | branched tubular glands at the bottom of the pits in the lamina propria |
3 types of gastric glands | cardiac glands gastric (fundic) glands Pyloric glands |
Pit to gland ratio of cardiac stomach | 1:1 length of gland should be the same as length of pit |
Fundic Glands can be divided into 3 parts | isthmus neck body |
Cells found in isthmus | parietal cell mucous neck cell |
Cells of body | chief cell argentaffin cell |
Surface mucous cells secrete | mucin |
Mucous neck cells secrete | alkaline mucin |
parietal cells secrete | HCl and intrinsic factor |
Chief Cells secrete | pepsinogen |
enteroendocrine cells secrete | gastrin |
Pit/Gland ratio in the pyloric area | 2:1 long pits and short glands |
Pyloric glands are found | in the pyloric region of the stomach |
Cells of the pyloric glands | mucous cells enteroendocrine cells parietal cells undifferentiated stem cells |
Mucous cells of the pyloric glands | secrete mucus and lysozyme |
Enteroendocrine cells of the pyloric glands | G cells secrete gastrin D cells secrete somatostatin |
gastrin | stimulates the parietal cells in the gastric glands to secrete HCl |
Somatostatin | regulates the release of the other hormones |
Parietal cells in the pyloric stomach | in limited number |
Histological features of the duodenum | simple columnar epithelium muscularis mucosa Brunner's Glands in submucosa Smooth muscle |
Brunner's Glands | only glands in submucosa past the esophagus secrete alkaline mucus that protects the mucosa from gastric acid. Maintains pH for pancreatic enzymes to work |
Muscularis externa of intestines | inner circular and out longitudal layers of smooth muscle Auerbach's plexus found between the two layers |
Histological features of the jejunum and ileum | long villi with lacteals crypts of lieberkuhn smooth muscle |
Crypts of Lieberkuhn | space in dark ridges |
Histological features of the jejunum and ileum | simple columnar epithelium long villi with lacteals crypts of lieberkuhn smooth muscle |
Crypts of Lieberkuhn | space in dark ridges |
Villus Structure | Villus and Crypt |
Villus cells | absorptive cells goblet cells Enteroendocrine cells crypt cells stem cells paneth cells |
Paneth cells | found in base of crypts they secrete antibacterial enzyme lysozyme |
Enteroendocrine cell products of the small intestine | secretin cholecystokinin gastric inhibiotry peptide motilin |
Secretin | stimulates growth and secretino of the exocrine pancreas |
cholecystokinin | stimulates growth and secretino of teh exocrine pancreas and contractino of teh smooth muscle of teh gall bladder, but inhibits gastric eptying |
GIP | gastric inhibitory peptide Inhibits HCl secretion by teh pareital cells in stomach |
Motilin | increases gut motility |
Illeum can be differentiated by having | Peyer's patches |
Appendix | similar sturcture to the colon but has shorter crypts of leiberkuhn and no teniae coli Large amounts of lymphoid tissue |
Hirschsprung's disease | absence of ganglion cells in the submucosal and myenteric plexuses of teh rectum. Feces remain in the colon causing it to enlarge |
Histological features of the colon | simple columnar epithelium NO vili crypts of leiberkuhn smooth muscle: teniae coli |
Teniae Coli | smooth rubber band sections of muscle |
Anal Canal | Look for apocrine glands Hair follicles stratified squamous non-keratinized epithelium smooth and skeletal muscle |
External sphincter is what kind of muscle? | skeletal |