Term
| Name the layers of a generic tubular organ. |
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Definition
| Epithelium, basement membrane, lamina propria mucosae, muscularis mucosa (variably present), submucosa, tunica muscularis, serosa OR adventitia. |
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Term
| What type(s) of glands (structure) are salivary glands? |
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Definition
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Term
| How much saliva is secreted per day in human? Sheep? Cow? |
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Definition
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Term
| 4 main functions of saliva? |
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Definition
| 1) Moistens food, 2) Lubricates mucosal surfaces, 3) Dissolves soluble substances (for taste bud sensing), 4) Keeps mouth clean |
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Term
| Name the major and minor salivary glands. Which species have them? |
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Definition
| Major: parotid (serous) , mandibular (mixed), sublingual (mucous). Also zygomatic (carnivores); molar (cats). Minor: labial, lingual, gustatory (w/ foliate and vallate taste buds), buccal, palatine, pharyngeal. |
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Term
| Put the following duct types in order: striated, lobar, interlobular, intercalated, intralobular, acinus. How can they be differentiated? |
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Definition
| Acinus, intercalated, striated, intralobular, interlobular, lobar. Acinus is where the cells secrete the product, so you’ll see granules (serous) or basophilic mucus (mucinous) in the cells. The ducts are differentiated by the epithelium lining them. Intercalated is squamous (simple), striated is cuboidal to columnar (often with infolded BM), intralobular is cuboidal to columnar, interlobular is pseudostratified, lobar is columnar stratified. |
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Term
| Which animals have keratinized esophageal lamina epithelialis? |
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Definition
| Ruminants, camelids, horse (less so), pig (less so) |
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Term
| In which layer of a tubular organ are blood vessels and nerves found? |
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Definition
Lamina Propria (also contains ducts, fibroblasts, and collagen + elastin)
Tunica Submucosa (also contains glands) |
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Term
| Which species have an esophageal lamina muscularis? |
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Definition
Horse, ruminant, cat all have isolated bundles which increase in thickness and confluence as stomach approaches. Dog has none in cranial esophagus, isolated bundles distally
Pig has none cranially, confluence distally
Llama has few scattered strands distally. |
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Term
| Describe spp differences in submucosal gland locations. |
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Definition
Pig: present in cranial esophagus only.
Dog: present throughout to cardiac rgn of stomach; more in distal esophagus
Horse, ruminant, cat: present only at pharyngoesophageal limen
Llama: abundant throughout; more cranially. |
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Term
| Describe spp differences with tunica muscularis of esophagus: |
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Definition
Dog, ruminant, llama: entirely striated
Horse: striated in cranial 2/3, smooth in distal 1/3
Pig: 1/3 striated, 1/3 mixed, 1/3 smooth
Cat: 4/5 striated (cranially), 1/5 smooth (distally) |
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Term
| Which cells found in a gastric gland produce HCl? |
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Definition
| Parietal cells (maintain pH <1.0-2.0) |
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Term
| Which cells found in a gastric gland produce gastrin? |
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Definition
| Enteroendocrine cells (gastrin is a paracrine hormone; along with ACh and histamine, affects HCl secretion) |
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Term
| Which cells found in a gastric gland produce pepsinogen? |
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Definition
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Term
| What is the subglandular layer, and who has it? |
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Definition
| Between base of glands and lamina muscularis mucosa, the subglandular layer consists of a stratum granulosum (with fibrocytes) and a stratum compactum (with collagen). Helps prevent sharp pointy things from poking through stomach! Thus found in carnivores (protects from bones in diet). |
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Term
| What kind of epithelium lines forestomachs? |
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Definition
| Stratified squamous (all histologically similar, though grossly different arrangements of folds) |
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Term
| Function(s) of rumenal mucosa? |
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Definition
Outer layers of epithelium: protection
Inner layers: absorption of fatty acids produced by bacterial fermentation. |
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Term
| In which part of camelid GI tract are mucigenous glands found? |
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Definition
| C1 and C2 (not C3, which is more like abomasum of ruminants) |
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Term
| How can you tell the difference histologically between duodenum, jejunum, ileum? |
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Definition
| You can’t necessarily…they all have crypts and villi. Ileum will have Peyer’s patches but all will have MALT. Duodenum has submucosal Brunner’s glands to secrete HCO3- (neutralizes HCl from stomach) |
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Term
| Where are Paneth cells found and what do they do? |
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Definition
| Found just above muscularis mucosa (i.e. in the lamina propria of the mucosa) of intestinal crypts (small and large intestines), along with enteroendocrine cells and others. Function = anti-microbial. Secrete defensins, TNF, lysozymes. |
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Term
| Where are M cells found, and how can you identify them in H&E stain? |
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Definition
| Found in ileal Peyer’s Patches (SLO-GALT). Trick question: they can’t be id’d with H&E. BUT they are found on domes, and lack villi, so they are histologically different (though v. hard to tell). |
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Term
| Do M cells have lysozymes? |
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Definition
| No! They take up the antigen entire to present to T cells in the LP. Enterocytes, also found in MALT, contain lysozymes. |
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Term
| Where are crypts of Lieberkuhn found? What are they? |
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Definition
| Straight tubular glands secreting digestive enzymes. Found in the small and large intestines and cecum. |
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Term
| How can you tell the difference between large intestine and cecum histologically? |
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Definition
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Term
| How can you tell the difference between the small intestine and large intestine? |
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Definition
| No villi in large intestine/cecum |
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Term
| Put the following avian digestives organs in order: proventriculus, crop, gizzard, esophagus, jejunum, cloaca, duodenum, caeca, ileum, colon. |
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Definition
| Esophagus, crop, proventriculus, gizzard, duodenum, jejunum, ileum, caeca, colon, cloaca. |
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Term
| Which is the glandular stomach of the bird? What glands does it contain and what do they secrete? |
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Definition
| The proventriculus is the glandular stomach. Contains only one secretory cell type: oxynticopeptic cells. Secrete both HCl and pepsinogen. (Contrast to mammalian gastric cells?) |
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Term
| Describe the layers of the gizzard: |
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Definition
| Simple cuboidal epithelium. Lined by acellular koilin, secreted by mucosal glands in LP. (No keratin! Koilin is eosinophilic, though.) Submucosa, Tunica muscularis. |
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