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• What is the main responsibility of the digestive tract?

  Transporting and absorbing nutrients
• How do accessory digestive organs assist the digestive tract?

  They provide enzymes and lubricants
• What are the four layers of the GI tract organs?

  Mucosa, submucosa, muscularis externa, serosa/adventitia

  
• What role does the mucosa play in the digestive system?

  Forms a protective barrier and secretes substances
• What is the function of specialized cells in the stomach epithelium?

  Produce mucus and gastric acid for digestion
• What type of epithelium lines the esophagus?

  Stratified squamous moist epithelium

  
• How does the muscularis externa change in the esophagus?

  Transitions from skeletal to smooth muscle

  
• What characterizes the stomach's mucosa?

  Thick mucosa lined by surface sheet gland
• What is unique about the muscularis externa of the stomach?

  It has three subdivisions instead of two

  
• What are the prominent features of the small intestine?

  Villi and intestinal glands
• How do glands in the submucosa distinguish the duodenum?

  They are present only in the duodenum
• What distinguishes the large intestine from the small intestine?

  Lacks villi and has straight intestinal glands
• What are the taeniae coli in the large intestine?

  Three longitudinal strips of muscularis externa
• What are the layers and substructures of the alimentary tract?

  • Mucosa: epithelium, lamina propria, muscularis mucosa
  • Submucosa: blood vessels, lymphatics, nerves
  • Muscularis Externa: circular layer, longitudinal layer, oblique layer (stomach only)
  • Serosa/Adventitia: areolar connective tissue, simple squamous epithelium

  
• What is the primary function of the rumen in ruminants?

  Storage and microbial fermentation of ingesta
• What type of epithelium is found in the rumen?

  Keratinizing stratified squamous epithelium

  
• What is the mucosal surface of the reticulum composed of?

  Long primary and shorter secondary folds
• How does the omasum's structure differ from the reticulum?

  It has large, thin, leaf-like structures called laminae
• What is the abomasum analogous to in carnivores?

  Simple stomach of carnivores
• What distinguishes the equine stomach's mucosal regions?

  Proximal nonglandular and aboral glandular regions
• What is the pars esophagea in pigs?

  Nonglandular mucosa lined by stratified squamous epithelium

  
• What is the primary function of the proventriculus in birds?

  Produces pepsinogen and hydrochloric acid
• What is koilin in the gizzard?

  A carbohydrate-protein complex coating the mucosa
• What are the histological features of the liver?

  • Largest organ in the body
  • Divided into lobules by fibrous capsule
  • Each lobule has portal triads
  • Hepatocytes arranged in cords
  • Sinusoids between hepatocytes
  • Kupffer cells degrade worn-out structures
• What is the function of the hepatic portal vein?

  Brings nutrient-rich blood from the digestive tract
• What is the role of stellate macrophages in the liver?

  Degrade worn-out cellular structures
• How do sinusoids function in the liver?

  They allow nutrient-rich blood to interact with hepatocytes
• Where does bile produced by hepatocytes go?

  Released into bile canaliculi
• What are the key functions of the digestive system's accessory organs?

  • Produce digestive enzymes
  • Secrete lubricants
  • Aid in nutrient absorption
  • Facilitate digestion and transport
• What shape do the lobules of the liver resemble?

  Hexagonal
• What is contained in each portal canal of the liver?

  Hepatic portal vein, artery, lymphatic vessels, bile duct

  
• What are liver cells called?

  Hepatocytes
• What do hepatocytes form as they emanate from the lobule's center?

  Cords of cells
• What are the capillaries between hepatocyte cords called?

  Sinusoids
• What is the function of the perisinusoidal space of Disse?

  Provides separation between hepatocytes and sinusoids
• What do stellate macrophages (Kupffer cells) do?

  Degrade worn out cellular structures
• Where do sinusoids drain in the liver?

  Into the central vein
• What is the pathway of bile produced by hepatocytes?

  Released into bile canaliculi, then bile duct
• How do blood and bile travel in the liver lobule?

  Blood travels centrally, bile peripherally
• What does the gallbladder store?

  Bile