BIOS 256 Week 3 Lab ( Review of Mechanical Digestion in Gastrointestinal Tract) BIOS 256 Week 3 Lab Part: Lab Exercise: Review of Mechanical Digestion in Gastrointestinal Tract Show Less

Student Name: Christopher Laing BIOS256 Week 3 Lab Exercise Review of Mechanical Digestion in the Gastrointestinal Tract Introduction 1. Define the gastrointestinal tract (GI). The GI tract is a continuous tube, ~20 feet long, from mouth to anus. The organs involved are the mouth with the teeth, tongue, and salivary glands, the pharynx, esophagus, stomach, small intestine, large intestine, liver, gallbladder, and pancreas. 2. Identify three mechanical digestion activities. a. Mastication b. Peristalsis c. segmentation 3. Name two feedback loops that regulate digestive system smooth muscle responsible for propulsive and mixing movements. neural & hormonal Neural Regulation of Mechanical Digestion 4. Identify three neural systems that control the mechanical movements in the GI tract. a. enteric b. Autonomic c. central 5. Describe the role of the CNS with regard to swallowing. What is the stimulus? The CNS sends signals to the salivary glands to begin producing saliva to moisten the food and turn it into a bolus. Once the bolus is ready to be swallowed, the CNS detects this and sends the signal to do so 6. a. What are the components of the ANS (long) neural reflexes? The components of the ANS (long) neural reflexes are: the vagus nerve, parasympathetic nerve fibers in the GI tract, and the parasympathetic fibers of the sacral spinal cord b. What is the stimulus for ANS regulation? stretch stimuli and hormonal stimuli c. What do ANS neurons regulate with regard to mechanical digestion? What are the possible responses? ANS neurons regulate gland activity, increasing or decreasing secretions, and smooth muscle activity of the walls of the GI tract, increasing or decreasing motility