Ch 18 Digestive

Check all of the roles of trypsin in digestion.

-Plays a role in digestion of phospholipids -Activates other enzymes that cleave peptide bonds

Please check all that are a function of the liver

-Secretion of bile -Removal of compounds in the blood -Capable of protein synthesis

Please match the pancreatic enzyme with its function. 1. Digests starch 2. Digests protein 3. Digests triglycerides

1. Amylase 2. Trypsin 3. Lipase

Demonstrate an understanding of the digestive structures and functions of the stomach and pancreas by correctly matching the description, term, or structure to the either the stomach or pancreas. 1. Pancreas 2. Stomach

1. Amylase Trypsin Pancreatic islets Rich in Bicarbonate Accessory Digestive Organ 2. Pepsin Hydrochloric Acid (HCl) Gastric Pits Low pH Part of Gastrointestinal Tract Gastrin Somatostatin

Please match the phase of gastric regulation with its description. 1. Sight, smell, and taste of food cause stimulation of vagus nuclei; vagus stimulates gastric acid secretion 2. Stomach distension stimulates vagus nerve, resulting in acid secretion; amino acids and peptides in stomach stimulate acid secretion 3. Arrival of chyme in the duodenum stimulates a neural reflex that inhibits gastric activity

1. Cephalic phase 2. Gastric phase 3. Intestinal phase

1. Conditions Which Affect the Liver 2. Conditions Which Affect the Intestines

1. Cirrhosis porphyria jaundice steatosis 2. celiac disease e. coli ulcerative colitis

Match the phase of swallowing with the appropriate scenario or description. 1. Oral phase 2. Pharyngeal phase 3. Esophageal

1. Controlled solely by skeletal muscle and somatic motor neurons 2. Stimulated by receptors in the oropharynx 3. Food is moved via peristalsis

Please match the structure of the small intestine with its description. 1. The first 10 inches of the small intestine, extending from the pyloric sphincter 2. Middle two-fifths of the small intestine 3. Last three-fifths of the small intestine 4. Large folds in the mucosa and submucosa

1. Duodenum 2. Jejunum 3. Ileum 4. Plicae circulares

Please indicate whether each statement is true or false regarding brush border enzymes. 1. Brush border enzymes are secreted into the lumen, where they become activated. 2. The brush border enzymes that digest sugars include sucrase, maltase, and lactase. 3. The enzyme activity of the phosphatase category of brush border enzymes may be regulated by Vitamin D. 4. The peptidase category of enzymes includes aminopeptidase and enterokinase. 5. Alkaline phosphatase is necessary for the activation of the protein-digesting enzyme trypsin

1. False 2. True 3. True 4. True 5. False

1. HCl secretion is necessary in order for pepsin to complete the final steps of protein digestion. 2. Medications that block HCl secretion may impact the conversion of pepsinogen to pepsin. 3. The low pH provided by HCl secretion allows the pepsin enzyme to be freed from pepsinogen enzymes. 4. Both pepsin and HCl are enzymes necessary to begin protein digestion.

1. False 2. True 3. True 4. False

1. The combined processes of ingestion, mastication, deglutition, peristalsis, and segmentation 2. Exocrine and endocrine substances 3. The breakdown of food into smaller subunits for absorption 4. The passage of digested products into blood or lymph 5. Temporary storage and subsequent removal of digested molecules 6. Epithelium of the digestive system prevents penetration of pathological organisms and toxins

1. Motility 2. Secretion 3. Digestion 4. Absorption 5. Storage and elimination 6. Immune barrier

1. Simple columnar epithelium supported by a lamina propria 2. Highly vascular layer of connective tissue 3. Inner circular and outer longitudinal layers of smooth muscle; the myenteric plexus is between the layers 4. Areolar connective tissue covered with a layer of simple squamous epithelium

1. Mucosa 2. Submucosa 3. Muscularis 4. Serosa

Match the lipoprotein with it function. 1. High-density lipoproteins 2. Very-low-density-lipoproteins 3. Low-density lipoproteins 4. Chylomicrons

1. Remove and degrade cholesterol 2. Deliver triglycerides produced within the body to body cells 3. Deliver cholesterol produced in the body to various organs 4. Deliver lipids consumed in the diet to body cells

Please indicate whether each statement is true or false regarding protein digestion and absorption. 1. The digestion of proteins begins in the stomach with the action of pepsin. 2. Most digestion of proteins occurs in the duodenum and jejunum as a result of endopeptidases and exopeptidases. 3. In general, free proteins are able to enter the portal veins. 4. Free amino acids enter the bloodstream from the small intestine.

1. True 2. True 3. False 4. True

1. Chylomicrons 2. Mixed Micelles 3. Triglycerides 4. Lipase

1. Ultimately enters the venous system 2. Broken apart by the brush border for absorption 3. Reformed within the epithelial cells 4. Essential for hydrolysis of triglycerides

Please indicate whether each statement is true or false regarding the nature and significance of intestinal microbiota. 1. There are about 10 times more bacterial cells in the large intestine than there are human cells in the entire body. 2. Intestinal microbiota are generally not beneficial to digestive processes, such as absorption. 3. Some intestinal microbiota produce short-chain fatty acids, which account for about 10% of the calories in a Western diet. 4.The commensal microbiota in the intestines are not usually present at birth, but are acquired through infections and ingestion of bacteria.

1. true 2. false 3. true 4. false

Secretin

Potentiates the effects of acetylcholine on the acinar cells through the action of cyclic AMP as a second messenger Secreted in response to a decreased duodenal pH below 4.5 Stimulates the production and secretion of bicarbonate into the pancreatic juice Stimulates the bile duct cells to secrete bicarbonate into the bile

The intestinal microbiota play a number of roles in digestion and health. Check all of the statements that are correct regarding the intestinal microbiota.

Removal of the colon would have a greater impact on the microbiota population than removal of portions of the small intestine. A fecal transplant would be more successful from a family member than someone with the same blood type. Introducing a greater variety of microbiota may theoretically help an individual lose weight.

Which of the following hormones inhibit gastric gland secretions?

Secretin

Please check all that are a function of the liver.

Secretion of bileSecretion of bile Removal of compounds in the blood Conversion of glucose to glycogen Capable of protein synthesis

The sequence in the breakdown of the non-iron portion of the heme is ________.

heme, biliverdin, bilirubin, conjugated bilirubin, bilirubin derivatives, feces and urine

Hydrochloric acid is formed when ________.

hydrogen ions and chloride ions join in the duct of the gastric gland

Which of the following is the correct order for the major parts of the gastrointestinal tract?

mouth, esophagus, stomach, small intestine, large intestine

Defecation is stimulated by __________.

parasympathetic and local reflexes

Involuntary muscle contractions, which move a bolus through the gastrointestinal tract are called ________.

peristalsis

Carbohydrate digestion begins in the mouth with the secretion of __________, but most occurs in the duodenum as a result of the secretion of __________.

salivary amylase; pancreatic amylase

Most nutrient absorption occurs in the ________.

small intestine

Mass movements of the colon are integrated by __________.

the enteric plexus

What organ produces bile?

Liver

A 30-year-old patient, who had given up eating all animal products for 20 years, reintroduced meat, eggs and milk products into her diet. After a few days, she experienced abdominal pain, bloating and diarrhea. Her physician ordered blood work, which was normal, and there were no signs of infection or illness. What is the most likely cause of her symptoms?

Over the years, she lost the ability to produce lactase, preventing the digestion of lactose into glucose and galactose.

Which of the following occurs during the gastric phase of gastric secretion?

Gastrin begins to be secreted by the lower part of the stomach.

Which of the following stimulates the secretion of hydrochloric acid (HCl) by the parietal cells?

Histamine stimulates parietal cells to secrete acid.

Ion exchange molecules in the plasma membrane of the parietal cells will ________.

exchange bicarbonate ions going out for chloride ions coming in

Mass movements in the colon are stimulated by ________.

food in the stomach and chyme in the duodenum

Why is bicarbonate an important component of pancreatic juice?

Bicarbonate increases the pH, providing an optimal environment for the enzymes in pancreatic juice.

Bile is both composed of, and functions in, the breakdown of which of the following molecules?

Cholesterol

Cholecystokinin (CCK)

Stimulates trypsin, lipase, and amylase from the pancreas Stimulates acinar cells using a rise in cytoplasmic calcium as a second messenger Stimulated in response to protein and fat content in chyme Secretion continues until chyme passes through the duodenum and in the early region of the jejunum

Choose the correct statement regarding the esophagus and its lower esophageal sphincter.

The lower esophageal sphincter is not a true sphincter, allowing for necessary regurgitation of harmful contents.

A patient with inflammatory bowel disease must have his large intestine removed. What impact may this have on his dietary requirements?

The patient will need to make sure to increase his calorie intake to account for a significant decrease in short-chain fatty acid production.

The pancreatic juice contains a protein called pancreatic trypsin inhibitor. What is the potential consequence of a deficiency or lack of this protein?

Trypsin would be activated within the pancreas, causing destruction of the acini cells.

In the parietal cells, the enzyme carbonic anhydrase causes a reaction between __________ and __________.

carbon dioxide; water