Digestive Tings Flashcards
What are the functions of the GI system?
Prehensile: ingestion followed by fragmentation
Mechanical and enzymatic breakdown of nutrients
Absorption
Synthesis/ secretion
Excretion of waste material
What time of epithelium is present from the lips to the non glandular stomach ?
Stratified squamous epithelium
What type of epithelium is is present in the glandular stomach and intestines?
Simple columnar
What is a distinctive feature of the oral cavity in ruminants?
Dental pad - keratinized layer
The oral cavity is missing what layer?
Submucosa
The tongue is covered by ___________ epithelium dorsally and ____________ epithelium ventrally
Keratinized stratified squamous epithelium
Stratified squamous epithelium
The tongue is mainly made of ??
Skeletal muscle
The oral cavity and tongue both are missing a?
Tunica submucosa
What cells produce enamel?
Ameloblasts
Dentin is made by what type of cells?
Odontoblasts
What anchors the tooth to the gums? What cells make up this ligament?
Periodontal ligament
Fibroblasts
What cells form cementum?
Cementoblasts
Where is serosa present along the digestive tract?
Continuous with the mesenteric, omentum, and pleura
What is the tunica submucosa made of? What is its purpose?
Loose connective tissue
Facilitate motility of mucosa
What is the purpose of the tunica muscularis
Control lumen size and motility
Contains myenteric plexus
What is the difference between tunica serosa and tunica adventitia
Serosa = mesothelium and loose CT
Adventitia= loose/dense CT only (up against other structures - no epithelium)
Where is adventitia found along the digestive tract?
Portions of esophagus where passing through mediastinum, rectum, vagina,
What are the features of the espohagus?
Stratified squamous epithelium May have lamina muscularis mucosae Mucous glands in submucosa Tunica musclaris -skeletal or smooth muscle Tunica adventitia over most of course
What is the junction between glandular and non-glandular stomach
Margo Plicatus
Compare the features of the rumen, reticulum, and omasum.
Rumen- low papillae, stratified squamous epithelium
Reticulum- honeycomb mucosa, proventricles are lined by stratified keratinized squamous epithelium
Omasum- long omasal lamina, stratified squamous keratinized epithelium
What are the distinctive features of the stomach?
Mucous producing epithelium
Longitudinal Rugae. :(
Gastric pits = invaginations of lining epithelium
The gastric glands are lined by __________ that dips down into grastric pits
Simple columnar epithelium
What cells are prevalent in the cardiac gland region of the stomach
Mucous glands and a few parietal cells
What cells are predominant in the funding region of the stomach?
Parietal
Chief cells
What cells are predominant in the pyloric region of the stomach
Mucous glands
G cells -> produce gastrin
Chief cells/ Peptic cells secrete __________.
What is their appearance?
Pepsinogen
Basophilic with zymogenic granules, dense basally located nuclei
Parietal cells secrete _________. What is their appearance??
HCl
Large, round and eosinophilic cytoplasm, centrally located nucleus
How do you differentiate small and large intestine?
Small - both villi and intestinal glands (crypts of Lieberkuhn)
Large- no villi (smooth surface), only crypts of Leiberkuhn
How do you differentiate the different parts of the small intestine?
Duodenum- Brunners gland in tunica submucosa
Jejunum - there are no specific structures in connective tissue of submucosa
Ileum - Payers patches in tela submucosa
What is a payer patch? What cells are located in them?
Aggregations of lymphoid nodules
Bcells in peyers patches
What are M fold cells and where are they located?
Specialized epithelial cells that phagocytose GI and secrete content on the lymphocytes and macrophages of the peyers patch
Have surface projections
In the ileum … where the peyers patches are.
Intestinal epithelium has what types of cells?
Goblet Enterocytes Enteroendocrine Paneth cells Stem cells Intraepithelial lymphocytes
What is the function and location of the paneth cells?
Base of intestinal crypt
Both secretory and phagocytic functions - produce cryptidin and lysine
What is the function and location of eteroedocrine cells?
Localized in intestinal crypts
Produce serotonin, glucoinsulotropic peptide, chatecholamines, gastrin, somatostatin, serotonin, cholecystokinin, secretin, bombesin, enteroglucagon.. ect
What are the three different glandular regions of the anus?
Anal glands
Anal sac glands
Circumanal glands
The rectum ends in the anal canal that is lined by ____________________ epithelium
Stratified squamous
Keratinized by muco-cutaneous junction
Anal glands
Tubuloacinar (present in pigs and dogs)
In the submucosa of the anal canal
Location of anal sacs
Lined by keratinized, stratified squamous epithelium
Between the inner smooth muscle of internal anal sphincter and outer skeletal muscle of external anal sphincter
What type of glands are anal sacs?
Apocrine tubular (dog)
Apocrine tubular and sebaceous (cat)
Circumanal gland are located where? And what is their appearance?
Located in subcutis around anus in dogs
Subdeacons in upper portions and non-sebaceous in lower portion (resemble hepatocytes -> hepatoid glands )
What are the types of salivary glands?
Serous, mucous, and mixed
Salivary acini empty into __________ ducts, which will empty into __________ ducts
Intercalated
Striated
Liver has a dual blood supply from the _______ and ____________
Portal vein and hepatic artery
The liver is covered by mesothelium over a CT layer, this is known as _________
Glisson capsule
What are transported to the liver via lymph vessels ?
Chylomicrons
What is the exocrine function of the liver?
Bile (for lipid digestion)
What is the space between the sinusoid capillary endothelium and the hepatocyte
Space of Disse
Two grooves in neighboring hepatocytes, connected by tight junctions for the _________________________
Bile canaliculi
Macrophage cells of the liver are called?
Kupffer cells
What is the structure and function of a hepatocyte?
Usually described as a hexagonal shape
Storage of metabolites/ storage of energy
-lipids and carbohydrates are stored in the liver in the form of triglycerides and glycogen
The flow of blood and bile in the hepatic lobule
Blood flows from the portal area to the central vein through sinusoids
Bile flows form hepatic lobule to bile ductule in bile canaliculi
What is area on the edge of the hepatic lobule that contains a branch of the hepatic artery, portal vein, and bile ductule?
Portal triad (aka portobiliary space)
The classical liver lobule is _______ in shape with blood flowing toward the __________
Polyhedral/hexagonal
Central vein
A portal lobule is _______ in shape and is representative of the flow of _________ to the ________
Triangular in shape
Bile toward the the triad
A hepatic acinus refers to the ___________ flow between lobules
Vascular flow
Flow begins at triad toward central veins via sinusoidal capillaries (diamond shaped)
What are the zones of the hepatic acinus and how do they relate to nutrient distribution and injury
Zone 1 - (perilobular) high O2, nutrients, and pathogen exposure
Zone 2 - moderate O2, nutrients, and pathogen exposure
Zone 3- (centrilobular) low O2, nutrient, and pathogen exposure
Gall bladder .. tell me all the things
Accepts bile from cystic duct for storage
Many mucosal folds
Simple columnar epithelium has microvilli, tight junctions, mitochondria, and secretory vesicles
No muscularis mucosae
Tunica serosa around it
Pancreas have ____________ units that drain into ________ ducts lined by cuboidal cells
Tubuloacinar
Intercalated
Pancreas resembles a salivary gland, but differs by?
No striated ducts
Has endocrine pancreastic islets of Langerhans
The exocrine cells of the pancreas are ______ acinus with ________granules
Serous
Zymogen
