Please enable JavaScript.

Coggle requires JavaScript to display documents.

Digestion II (Two types of stomachs (Monogastric (primarily glandular)…

- - - - cats (and dogs to lesser extent) have additional layer (laminal subglandularis) between glands and muscularis mucosa. contains fibroblasts and dense collagenous fibers
      - Contains:
        
        rugae
        
        mucosa
        
        lumen
        
        submucosa
        
        muscularis externa
    - - cardiac
        
        secretes mucus
        
        simple, coiled, and tubular, lined my surface muscousal cells. parietal and EE (entero-endocrine) cells possible
      - gastric (fundic)
        
        secretes mucus, HCl, and pepsinogen
        
        tubular, lined by mucus neck cells
        
        Found in fundus and body
        
        morphology: long, tubular glands with pit, neck, and branched body
        
        pit/foveolae: mucus cells (produce mucosal barrier)
        
        neck: mucus cells and stem cells
        
        body: houses 5 cell types
        
        mucus cells
        
        chief cells
        
        produce pepsinogen
        
        parietal cells
        
        produce HCl
        
        stem cells
        
        enteroendocrine cells
        
        produce gastric hormones
        
        Types of fundic gland cells
        
        mucous cells (line gastric pit and neck)
        
        produce mucins that combine with H2O and form protective gel
        
        mucus blanket (gastric mucousal barrier) traps bicarb, the alkalinity of which offsets the acids secreted by gastric glands and keeps the pH around epithelium at around 7.0
        
        mucus layer disruption results in peptic ulcers and/or adenocarcinoma of stomach
        
        Parietal gland cells
        
        found in neck and upper 1/3 of gland
        
        eosinophilic cytoplasm
        
        produce HCl (lowers stomach pH to 1-2)
        
        stimulated to produce HCl by EE hormone --> gastrin
        
        chief cells
        
        found in lower 1/3 of gland
        
        basophilic cytoplasm
        
        houses zymogenic granules
        
        proenzyme pepsinogen
        
        when pepsinogen is released, it interacts with HCl to create pepsin, the proteolytic enzyme that digests proteins
        
        EE cells
        
        found in mucosa along GI
        
        many types, monohormonal
        
        G cells
        
        1 more item...
        
        D cells
        
        1 more item...
        
        produce hormones
        
        enter lamina propria
        
        2 more items...
        
        function: involved in regulation of water, enzyme secretion, motility of GI, mucosal growth, etc
      - pyloric
        
        secretes mucus/lysozyme
        
        simple, tubular, lined by mucus neck cells
  - - - large folds (laminae omasi) with keritinizaed stratified squamous eipthlium.
      - no glands
      - muscle core of large folds from muscularis submucosa and muscularis externa
    - - True glandular stomach
        
        homogenizes and processes food
        
        chemically via enzymes and acid
        
        mechanically via muscular churning
        
        epithelium changes from stratified squamous to simple columnar. very obivous
        
        lined by longitudinal folds/rugae (gone when stomach distended)
        
        mucosal cells in epithelium secrete protective gel layer (gastric mucosal barrier)
        
        protects stomach from auto-digestion
        
        protects stomach from abrasion from food