QUESTIONS

1. The annular contractions (especially in the transverse & descending colon) fold the large intestine into sacs called _______________. These contractions form & reform in new sites to help mix ingesta while absorption occurs. These contractions are called _______________.
    
2. When contents of one of these sacs moves into the next sac this is called _______________.
    
3. When several sacs together contract simultaneously to move contents from one area into the next, this is called _______________. (extra points if you get this one right) Hint:  this is not peristalsis. Colonic peristalsis is more of a progressive wave than a squirt.
    
4. The only functionally important secretions of the large intestine are _______________, _______________, and  _______________.
    
5. The three functions of the large intestine are _______________,
   _______________, & _______________.
    
6. There are two types of fiber: soluble (which attracts water & forms a gel) & insoluble fiber.  Which is which below:
   
   a) oat bran
   
   b) newspaper
   
   c) lignin
   
   d) pectins
   
   e) psyllium
   
   f) beans
   
   g) vegetables
   
   h) fruits
   
   i) increases fecal mass
   
   j) increases large intestine transit time
   
   k) decreases large intestine transit time
    
7. On a package of pet food, "Crude Fiber" is listed on the guarenteed analysis. What fibers are included in this measure?
    
8. Constipation matching (oh, boy!)
   
   Match the cause of constipation a-j on the left to the category 1-6 on the right. (You may use categories more than once):
   
   a) old pelvic fracture with               1) Environmental factor
      narrow pelvic canal
   
   b) Dirty litter box                               2) Dietary factor/
                                                                      inappropriate ingestion
   
   c) Renal failure                                   3) Painful defecation
   
   d) Hair in feces from                         4) Colon obstruction
      excess grooming
   
   e) Hospitalization stress                   5) Altered motility
   
   f) Antihistamine administration       6) Drugs
   
   g) Anal sac abscess
   
   h) Prostatomegaly
   
   i) Hypothyroidism
   
   j) Feline dysautonomia
    
9. What does "pseudocoprostasis" usually refer to?
    
10. Match constipation drug a-d on the left with category 1-4 on the right:
    
    a) Milk                                               1) Bulk forming laxative
    
    b) Milk of Magnesia                       2) Emollient laxative
    
    c) Canned pumpkin                         3) Saline based laxative
    
    d) DSS                                               4) Hyperosmotic agent
     
11. If you use cisapride for an obstipated cat, do you also need stool
    softeners? Do you need to deobstipate first or can you just start the drug?
     
12. Bisacodyl stimulates the sensory nerve endings in the large intestine to produce parasympathetic reflexes and increase colon peristalsis. It has been recommended to only use this drug 20-30  days on then 20-30 days off. Why can't you just keep using this drug?
     
13. Innervation of the large intestine cranially is by the _______________ nerves & caudally  by the _______________ nerves.
     
14. The more scientific name for Boxer colitis is _______________. It usually affects boxer that are (choose one)
             young         middle aged         older.
    
    
    
    
     

ANSWERS

1. The sacs are called "haustra;" the contractions are called "haustral contractions."
   
   
   
   
    
2. Sac to sac movement is called "segmental propulsion."
   
   
   
   
    
3. This squirting movement is called - yes - "systolic minihaustral propulsion."
   
   
   
   
    
4. The only functionally important large intestinal secretions are:
   
   1) mucus (to lubricate feces)
   
   2) bicarb (to neutralize the acid bacterial fermentation products)
   
   3) potassium (this is not a large amount & it normally gets reabsorbed anyway but if there's big diarrhea there isn't time for reabsorption.  This is where the big K+ loss in diarrhea occurs)
   
   
   
   
    
5. The functions of the colon are:  fecal storage, absorption of water & electrolytes, & carbohydrate fermentation.
   
   
   
   
    
6. Fiber is anything that isn't digested by the small intestine.  Soluble fiber is happily digested by the L.I. bugs.  Insoluble fiber is +/- digested by the L.I. bugs.
   
   a) oat bran > soluble
   
   b) newspaper > insoluble
   
   c) lignin > insoluble
   
   d) pectins > soluble
   
   e) psyllium > soluble
   
   f) beans > soluble
   
   g) vegetables > insoluble
   
   h) fruits > soluble
   
   i) increases fecal mass > insoluble  (actually both do)
   
   j)increases transit time > soluble
   
   k) decreases transit time > insoluble
   
   
   Both soluble and insoluble fiber can increase fecal bulk which may be helpful in the  colon if extrea stimulation of the myoelectric activity is needed (might help w/a megacolon situation).  Soluble fiber in general is highly fermentable into short chain fatty acids, mainly butyrate (which happily is the principal source of energy for the colonocyte).  All this fermentation producing short chain fatty acids can reduce the pH in the colon and discourage pathogen growth. Soluble fibers slow down the passage of food in the intestine thus allowing for more water absorption.
   
   
   
   
    
7. Crude fiber measures only lignin & cellulose (not hemicellulose, pectins, gels or mucilages). Many nutritionists think that "crude fiber" is  thus not a very useful term & use "soluble & insoluble fiber" instead.  Where does soluble vs. insoluble fit into treating colitis, diabetes mellitus, obesity? I don't think any one knows.
   
   
   
   
    
8. pelvic fx >>>> colon obstruction
   
   dirty litter box >>>> environmental factor
   
   renal failure >>>> altered motility (lyte imbalance)
   
   hair in feces >>>> dietary
   
   hospitalization >>>> environmental
   
   antihistamines >>>> drugs
   
   anal sac abscess >>>> pain on defecation
   
   prostatomegaly >>>> colon obstruction (could also be pain on defecation)
   
   hypothyroidism >>>> altered motility
   
   feline dysautonomia >>>> altered motility
   
   
   
   
    
9. Pseudocoprostasis usually refers to the mat of hair and poop that sometimes covers an animal's anus.
   
   
   
   
    
10. Milk >>>> hyperosmotic agent
    
    Milk of Magnesia >>>> Saline base
    
    Canned pumpkin >>>> bulk former
    
    DSS >>>> Emollient
    
    
    
    
     
11. If you use cisapride you bet your sweet rubber gloves you have to use stool softeners and you have to deobstipate the cat first or it won't work.
    
    
    
    
     
12. Bisacodyl (which may be a drug of yesteryear now that we have cisapride) was thought to damage the myenteric plexus with all its parasympathetic stimulation. My impression is that it is not for sure that this is a problem but this is why those who recommended only brief courses of the drug did so.
    
    
    
    
     
13. Innervation of the large intestine is by the vagi cranially & the pelvic nerves caudally.
    
    
    
    
     
14. The more scientific name for Boxer colitis is "Histiocytic Ulcerative Colitis." On biopsy one finds macrophages laden with polysaccharides. These macrophages are PAS+.  No one knows exactly what's going on with the macrophages but there are many theories - lysosomal enzyme deficiency etc.
    
    It usually affects boxers < 2 years of age.