BIOS 256 LAB 1 ASSIGNMENT

BIOS 256 Lab 1 Assignment Part A. Reviewing Your Knowledge pg. 593-596 A. LAYERS OF THE GASTROINTESTINAL TRACT Name the layers of the GI tract that are described. The layer that contracts to churn food or move food along Layer consisting of a membrane that lines a body cavity that opens to the exterior; overlays smooth muscle Areolar connective tissue layer located deep to the mucosa. A serous membrane that is the external layer of a GI tract organ. B. GASTROINTESTINAL TRACT ORGANS Write the name of the term that is described. Its only function is propulsion. A continuous digestive tube from the mouth to the anus. Conducts both air and food. Primary site of nutrient absorption; is composed of 3 sections. Section of small intestine that receives bile, pancreatic secretions, and food from the stomach. Churns food and begins protein digestion. Has two sphincters that control elimination of feces from the body. Has regions called the cardia, fundus, body, and pylorus. Has regions called the cecum, colon, rectum, and anal canal. Receives secretions from salivary glands; mastication occurs here. C.GASTROINTESTINAL TRACT ORGANS AND ASSOCIATED STRUCTURES Write the name of the organ that is described. Finger-like extensions increasing surface area in the small intestine. Folds in the gastric mucosa. Permanent deep ridges in the small intestine mucosa. Sphincter valve between the stomach and duodenum. Serous membrane that lines the abdominal wall. Serous membrane that covers the abdominal organs. Sphincter that connects the small and large intestine. Fluid that begins digestion of carbohydrates. Bony plate between the mouth and nose. Forms a brush border; extension of epithelial cell plasma membrane. Keeps food and fluids from going up into the nasopharynx. Area between the lips and teeth. Region of the stomach where the lower esophageal sphincter meets the stomach. Has regions called ascending, transverse, descending, and sigmoid. Narrowed region of the stomach before the small intestine. A series of gathered pouches in the large intestine. D. ACCESSORY DIGESTIVE ORGANS AND THE PERITONEUM Write the name of the organ that is described. Mechanically breaks up food during mastication. Secretes enzymes that digest carbohydrates, proteins, lipids, and nucleic acids. Salivary glands located under the tongue with ducts that open in the floor of mouth. Produces and secretes bile into ducts. Peritoneal membrane that holds the small intestine to the posterior abdominal wall. The secretions of this gland join with bile to enter the duodenum. Peritoneal fold that holds the liver to the anterior abdominal wall. Manipulates food in mastication. Fatty, large fold of peritoneum covering the transverse colon and small intestine. Largest salivary glands whose ducts open by the upper second molars. Stores and secretes bile into the duodenum. Peritoneal membrane that attaches the stomach and duodenum to the liver. Salivary glands whose ducts open lateral to the lingual frenulum. Trace bile from its secretion to the gallbladder for storage and concentration, and then to the duodenum, listing the structures in order, using Figure 10. Trace blood from the hepatic portal vein through the liver to the inferior vena cava, listing the structures in order, using Figure 12 E. Identification of Digestive System Organs Identify the organs in Figure 34.13 and state whether the organ is a GI tract organ or an accessory digestive organ. Part B. Using Your Knowledge pg. 597-598 A. Digestive System Structure A hiatal hernia or failure of the lower esophageal (cardiac) sphincter to close causes the stomach contents to back up into the esophagus. This causes the esophageal wall to have a burning sensation (heartburn) and, in serious cases, bleeding. What causes the burning sensation and bleeding to occur? How does removal of the gallbladder affect digestion? B. Identification of Digestive System Structures Identify the structures numbered 3–6 on the X-ray of the human stomach shown in Figure 34.14. Identify the structures numbered 7–10 on the X-ray of the lower GI tract, shown in Figure 34.15.