System Function: Digestion - Massage and Bodywork Licensing Examination Mblex
- What is the sphincter that regulates chyme release from stomach into the duodenum?
- Pyloric sphincter. It controls the rate of chyme passage to the small intestine, allowing time for neutralization and digestion.
- What are villi?
- Fingerlike mucosal projections that increase absorptive surface area. Villi contain blood vessels and lacteals to transport absorbed nutrients, maximizing contact with digested material.
- Which digestive process is the mechanical breakdown of food by chewing and stomach churning?
- Mechanical digestion. This process physically reduces food particle size to increase surface area for enzymatic action and facilitate swallowing.
- What is the term for rhythmic, wave-like contractions that propel food through the GI tract?
- Peristalsis. These contractions create pressure gradients that move boluses of food along the digestive tract efficiently.
- Which organ stores and concentrates bile for release into the small intestine?
- Gallbladder. It concentrates bile by absorbing water and stores it until hormonal signals trigger release via the common bile duct.
- Identify the three sections of the small intestine in correct order from stomach to large intestine.
- Duodenum, jejunum, ileum. These segments progressively handle digestion and absorption, with the duodenum receiving chyme and the ileum completing nutrient uptake.
- What is the name of the muscular tube that carries food from pharynx to stomach?
- Esophagus. It uses peristaltic waves to transport the food bolus from the pharynx to the stomach via gravity and muscle action.
- Which salivary enzyme begins starch digestion in the mouth?
- Salivary amylase (ptyalin). This enzyme hydrolyzes starch into maltose and dextrins, starting carbohydrate digestion in an alkaline environment.
- What is the acidic secretion of the stomach that denatures proteins and kills many microbes?
- Hydrochloric acid (HCl). Produced by parietal cells, it creates a low pH environment to activate pepsinogen and provide antimicrobial protection.
- What is the primary function of saliva in digestion?
- Lubricates food and begins carbohydrate digestion. Saliva moistens food for easier swallowing and contains amylase to initiate starch breakdown into maltose.
- What is the main role of pancreatic bicarbonate in the duodenum?
- Neutralizes acidic chyme from the stomach. Bicarbonate raises the pH of chyme to an optimal level for intestinal enzyme activity and protects the mucosa.
- Which stomach enzyme begins protein digestion by breaking proteins into peptides?
- Pepsin. Activated from pepsinogen in acidic conditions, it cleaves peptide bonds to initiate protein catabolism.
- Which digestive process is the chemical breakdown of food by enzymes, acids, and bile?
- Chemical digestion. Enzymes and other chemicals break down complex molecules into simpler forms that can be absorbed by the body.
- What is the term for localized intestinal mixing contractions that move chyme back and forth?
- Segmentation. These contractions enhance mixing of food with digestive juices without net forward movement, aiding nutrient absorption.
- What are microvilli?
- Microscopic projections on enterocytes forming the brush border. Microvilli expand the apical surface of absorptive cells, housing brush border enzymes for final digestion steps.
- Which hormone stimulates pancreatic enzyme secretion in response to fats and proteins in chyme?
- Cholecystokinin (CCK). Released by duodenal cells, it promotes enzyme secretion from the pancreas to digest fats and proteins effectively.
- Which hormone stimulates pancreatic bicarbonate secretion in response to acidic chyme?
- Secretin. Produced in response to low duodenal pH, it stimulates bicarbonate release to neutralize stomach acid.
- What is the sphincter at the junction of the esophagus and stomach called?
- Lower esophageal (cardiac) sphincter. This sphincter relaxes to allow food entry into the stomach and contracts to prevent reflux of gastric contents.
- Which organ produces bile?
- Liver. Hepatocytes synthesize bile salts from cholesterol to support fat digestion and elimination of waste products.
- Which organ secretes digestive enzymes and bicarbonate into the duodenum?
- Pancreas. Acinar cells produce enzymes for macronutrient breakdown, while ductal cells secrete bicarbonate to buffer acidity.