Bios 256 Week 3 Lab

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Student Name: BIOS256 Week 3 Review of Mechanical Digestion in the Gastrointestinal Tract Introduction 1. Define the gastrointestinal tract (GI). The GI tract, or alimentary canal, is a tube that extends from the mouth to the anus. 2. Identify three mechanical digestion activities. a. Chewing b. Mixing of food with saliva by tongue c. Churning food in the stomach and segmentation of the intestines 3. Name two feedback loops that regulate digestive system smooth muscle responsible for propulsive and mixing movements. Hormonal feedback loops and neural feedback loops. Neural Regulation of Mechanical Digestion 4. Identify three neural systems that control the mechanical movements in the GI tract. a. CNS b. ANS-Long Reflexes c. ENS-Local Reflexes 5. Describe the role of the CNS with regard to swallowing. What is the stimulus? The CNS controls voluntary swallowing movements. The presence of food is the stimulus for voluntary digestive movements. 6. a. What are the components of the ANS (long) neural reflexes? The components of the ANS (long) neural reflexes include a CNS control center in the spinal cord and the brain. b. What is the stimulus for ANS regulation? Distention for many involuntary digestive movements. c. What do ANS neurons regulate with regard to mechanical digestion? What are the possible responses? The ANS neurons regulate involuntary smooth muscular movements. The response is either increased or decreased contraction of the muscularis. 7. Where are enteric nervous system plexuses located? The myenteric plexus is located between the longitudinal and circular layers of muscle in the tunica muscularis, the submucous plexusis buried in the submucosa. Mastication 8. Define
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