Digestive System

Q: What are the four types of carbohydrates?

• A: Polysaccharides, disaccharides, oligosaccharides, monosaccharides.

Q: How is excess glucose stored in the body?

• A: As glycogen or fat.

Q: What is the end product of protein digestion?

• A: Amino acids.

Q: What are the three forms of lipids in the body?

• A: Triglycerides, phospholipids, cholesterol.

Q: What is the alimentary canal?

• A: The continuous tube from mouth to anus.

Q: What is the mesentery?

• A: A double-layered membrane that holds digestive organs in place.

Q: What structure connects the liver to the stomach?

• A: The lesser omentum.

Q: What is the purpose of the hepatic portal vein?

• A: It transports nutrients from the digestive organs to the liver.

Q: What are the layers of muscle in the alimentary canal?

• A: Circular and longitudinal layers.

Q: How many muscle layers does the stomach have?

• A: Three (circular, longitudinal, and oblique).

Q: Name the five sphincters of the alimentary canal.

• A: Upper esophageal, lower esophageal, pyloric, ileocecal, anal.

Q: What forms the hard palate?

• A: Maxilla and palatine bones.

Q: Which three pairs of tonsils are found in the mouth?

• A: Palatine, pharyngeal, and lingual tonsils.

Q: Name the three pairs of major salivary glands.

• A: Parotid, submandibular, and sublingual glands.

Q: How much saliva is produced daily?

• A: About 1,500 ml.

Q: What is the hardest substance in the body, found on teeth?

• A: Enamel.

Q: What is the pulp cavity?

• A: The innermost part of the tooth containing blood vessels and nerves.

Q: How many teeth do adults typically have?

• A: Up to 32 teeth.

Q: What is peristalsis?

• A: The wave-like muscle contractions that move food through the digestive tract.

Q: What are the primary functions of the esophagus?

• A: To transport food from the mouth to the stomach.

Q: Through which opening does the esophagus pass through the diaphragm?

• A: The esophageal hiatus.

Q: What type of epithelium lines the esophagus?

• A: Stratified squamous epithelium.

Q: What type of epithelium lines the stomach?

• A: Simple columnar epithelium.

Q: What substance protects the stomach lining from its acidic environment?

• A: Mucus.

Q: What do parietal cells in the stomach secrete?

• A: Hydrochloric acid (HCl) and intrinsic factor.

Q: What is intrinsic factor necessary for?

• A: Absorption of vitamin B12.

Q: What enzyme do chief cells secrete?

• A: Pepsinogen.

Q: What hormone do enteroendocrine cells secrete?

• A: Gastrin.

Q: What is the function of gastrin?

• A: To stimulate HCl production in the stomach.

Q: What is chyme?

• A: The semi-liquid mixture of food and digestive juices in the stomach.

Q: Through which sphincter does chyme enter the small intestine?

• A: The pyloric sphincter.

Q: Name the three parts of the small intestine.

• A: Duodenum, jejunum, ileum.

Q: Where does most nutrient absorption occur?

• A: In the small intestine.

Q: What are villi?

• A: Small, fingerlike projections that increase surface area for absorption in the small intestine.

Q: What is a lacteal?

• A: A lymphatic vessel in each villus that absorbs fats.

Q: What are microvilli?

• A: Microscopic projections on the surface of epithelial cells in the small intestine.

Q: Where do the bile duct and main pancreatic duct empty?

• A: Into the duodenum.

Q: What hormone relaxes the sphincter to release bile?

• A: Cholecystokinin (CCK).

Q: What are Peyer's patches?

• A: Lymphoid tissue in the small intestine.

Q: What structure stores bile?

• A: The gallbladder.

Q: Which liver ducts form the common bile duct?

• A: The hepatic and cystic ducts.

Q: What is a portal triad in the liver?

• A: A grouping of a bile duct, hepatic artery, and hepatic portal vein.

Q: What does the liver convert excess glucose into?

• A: Glycogen.

Q: Name the four fat-soluble vitamins stored in the liver.

• A: Vitamins A, D, E, K.

Q: What are bile salts?

• A: Compounds derived from cholesterol that help emulsify fats.

Q: How are bile salts recycled?

• A: Through the enterohepatic circulation.

Q: What is the pancreas's exocrine function?

• A: To produce digestive enzymes.

Q: What is the pancreas’s endocrine function?

• A: To produce insulin and glucagon.

Q: What enzyme digests starch in the mouth?

• A: Salivary amylase.

Q: What enzyme continues starch digestion in the small intestine?

• A: Pancreatic amylase.

Q: Where does protein digestion begin?

• A: In the stomach with pepsin.

Q: What enzyme helps digest protein in the small intestine?

• A: Trypsin.

Q: What is emulsification?

• A: The process of breaking down fats into small droplets.

Q: What enzyme digests fats?

• A: Pancreatic lipase.

Q: What is the large intestine's primary function?

• A: Absorbing water and electrolytes.

Q: What are haustra?

• A: Pouches in the large intestine formed by muscle tone.

Q: What part of the colon is between the right and left colic flexures?

• A: The transverse colon.

Q: Where is the sigmoid colon located?

• A: Before the rectum in the lower abdomen.

Q: What is the appendix attached to?

• A: The cecum.

Q: What type of muscle forms the internal anal sphincter?

• A: Smooth muscle.

Q: What type of muscle forms the external anal sphincter?

• A: Skeletal muscle.

Q: What does the colon contain to help prevent infection?

• A: Bacteria that produce vitamin K and other beneficial substances.

Q: What are monosaccharides?

• A: The simplest form of carbohydrates absorbed by the intestine.

Q: What breaks down starch into maltose in the mouth?

• A: Salivary amylase.

Q: Which enzyme breaks down lactose in the small intestine?

• A: Lactase.

Q: What are zymogens?

• A: Inactive forms of digestive enzymes.

Q: Which part of the stomach controls chyme release into the duodenum?

• A: The pylorus.

Q: What is segmentation?

• A: Rhythmic contractions in the intestine to mix food.

Q: What is the primary function of bile?

• A: To emulsify fats.

Q: What triggers the release of pancreatic juice?

• A: Secretin and CCK in response to acidic chyme.

Q: Which enzyme digests nucleic acids?

• A: Nuclease.

Q: What is the role of bicarbonate in pancreatic juice?

• A: To neutralize stomach acid in the small intestine.

Q: Which layer of the GI tract contains blood vessels and lymphatics?

• A: The submucosa.

Q: Where is the myenteric plexus located?

• A: Between the layers of the muscularis externa