Term
| Junction between small & large instine |
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Definition
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Term
| Role of cecum & colon (3) |
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Definition
-absorption of water & electrolytes
-fermentation & absorption of undigested organic material
-storage of feces |
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Term
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Definition
| interstitial cells of cajal |
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Term
| Which pacemakers are relatively constant as far as location/placement/activity? |
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Definition
-pacemaker at proximal end of colon
-pacemaker at junction of transverse & descending colon |
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Term
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Definition
| intense mixing (retropulsion) |
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Term
| Wht does the colon secrete? |
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Definition
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Term
| What gets absorbed in the colon? |
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Definition
-VFAs produced by bacterial fermentation
-vitamins produced by bacteria (B,K)
-electrolytes & water |
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Term
| Is absorption of water & electrolytes in the colon an active or passive process? |
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Definition
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Term
| Absorption of potassium is by (active/passive) diffusion |
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Definition
passive
-water is absorbed first, as you move down the GIT concentration of K+ increases so it will move down concentration gradient |
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Term
| In normal circumstances, water is absorbed where? |
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Definition
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Term
| When does the colon absorb water? |
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Definition
| in instances of dehydration (aldosterone is released which promotes Na+ absorption and therefore water absorption) |
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Term
| What is malabsorptive diarrhea |
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Definition
| Damage to GI mucosa = less absorptive surface = increased osmolarity in intestinal lumen = more water lost in feces |
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Term
| What is hypersecretory diarrhea? |
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Definition
| Toxins can either cause Cl or HCO3- channels to open, or tight junctions to leak, both of which cause water to be 'lost' into the intestinal lumen |
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Term
| Describe the anatomy of the anal sphincter & innervation |
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Definition
Internal Sphincter
-smooth muscle, controlled by ENS & PSNS
-pelvic nerve
External sphincter
-skeletal muscle controlled by CNS (conscious control)
-pudendal nerve |
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Term
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Definition
| -rectum fills with feces, stimulates ENS to relax internal sphincter, stimualtes PNS to further relax internal, CNS will dictate posture change, abdominal contraction, defecation |
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