Term
| What are the three phases of swallowing and what does each phase entail? |
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Definition
1. Buccal (oral) - break up food, chew, mix with saliva, initiate swallowing
2. Pharyngeal - Initiate pharyngeal peristalsis, close epiglottis, relax upper esophogeal sphincter
3. Esophageal phase - Initiate esophageal peristaltic wave, relax lower exophageal sphincter |
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Term
| What is the main benefit of segmented contraction in the small intestine? |
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Definition
| Provides mixing of the chyme, allowing concentration of the components to mix throughout the small intestine aiding reabsorption through the epithelium |
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Term
| What is the MMC and what is its role in the GI tract? |
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Definition
Migrating motor complex
It is a period of changing electrical waves present in the stomach to the end of the ileum that occur during fasting. It is suppressed by eating a meal. It serves to keep the GI tract clean between meals from overgrowth of bacteria and sweep larger, undigestable objects out of the stomach |
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Term
| Describe contraction in the colon |
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Definition
1. Presence of teniae coli lead to increased contraction
2. Circular muscle leads to slow, segmental contractions (haustration)
3. Peristaltic movement happens 1-3 times a day independent of extrainsic innervation |
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Term
| How is the anal sphincter different from other sphincters? |
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Definition
| It has 2 parts, outer and inner. Inner is not under voluntary control (smooth muscle) outer is (striated muscle) |
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