Adrianne, a fifty-seven year old bank manager, had recently been waking up in the middle of the night with abdominal pain. This was happening several nights a week. She was also experiencing occasional discomfort in the middle of the afternoon. Adrianne decided to schedule an appointment with her physician.
The physician listened as Arianne described her symptoms and then asked Arianne some questions. He noted that Arianne’s appetite had suffered as a result of the pain she was experiencing and as a result of the fear that what she was eating may be responsible for the pain. Otherwise, Arianne seemed fine.
The physician referred Arianne to another physician that specialized in internal medicine and had Arianne make an appointment for a procedure called an endoscopy. The endoscopy was performed at a hospital later that week. During the procedure, a long, thin tube was inserted into Arianne’s mouth and directed into his digestive tract. The end of the tube was equipped with a light source and a small camera which allowed the physician to observe the interior of Arianne’s stomach. The endoscope was also equipped with a small claw-like structure that the physician could use in order to obtain a small tissue sample from the lining of Arianne’s stomach, if required.
The endoscopy revealed that Arianne had a peptic ulcer. Analysis of a tissue sample taken from the site showed that Arianne also had an infection that was caused by Helicobacter pylori bacteria. The physician who performed the endoscopy gave Arianne prescriptions for two different antibiotics and a medication that would decrease the secretion of stomach acid. The physician also instructed Arianne to schedule an appointment for another endoscopy procedure in 6 months.
A peptic ulcer is a sore that occurs in the lining of a part of the gastrointestinal tract that is exposed to pepsin and acid secretions. Most peptic ulcers occur in the lining of the stomach or duodenum. About 90% of all duodenal ulcers and 80% of all gastric ulcers are caused by H. pylori infection. Most of the remaining peptic ulcers are caused by long-term usage of certain anti-inflammatory medications like aspirin.
There is still some question as to how H. pylori is spread. However, H. pylori has been identified in the saliva of infected individuals and may be spread via this fluid. H. pylori bacteria have the ability to survive the acid environment in the stomach because they produce enzymes that neutralize stomach acids. They also have the ability to move through the mucous membrane lining the stomach or duodenum and take up residence in the underlying connective tissue. The damage to the mucous membrane that results from a H. pylori infection allows pepsin and hydrochloric acid to further damage the wall of the stomach or duodenum. The sore that results is the peptic ulcer.
1. Describe the functions of the following components of gastric juice.
a. Hydrochloric acid
d. Intrinsic factor
2. Why don’t the components of gastric juice damage the wall of the stomach in the absence of a H. pylori infection?
3. Why don’t most other types of bacteria produce ulcers?
1. Where does carbohydrate digestion begin?
2. What enzyme starts the digestive process and how does it work?
3. Explain the role the stomach plays in carbohydrate digestion.
4. How does the pancreas contribute to carbohydrate digestion?
5. Where does the majority of carbohydrate digestion occur, what are the enzymes involved and how do they each function?
6. In what form are carbohydrates absorbed and how are they absorbed?
7. Where does protein digestion begin?
8. Explain the role the mouth plays in protein digestion.
9. What enzyme starts the digestive process and how does it work?
10. How does the pancreas contribute to protein digestion?
11. Where does the majority of protein digestion occur, what are the enzymes involved and how do they each function?
12. In what form are proteins absorbed and how are they absorbed?
13. Where does lipid digestion begin?
14. What enzymes start the digestive process and how do they work?
15. Explain the role the mouth plays in lipid digestion.
16. How does the pancreas contribute to lipid digestion?
17. Where does the majority of lipid digestion occur, what are the enzymes/chemicals involved and how do they each function?
18. In what form are lipids absorbed and how are they absorbed and in what vessel are they absorbed into?
19. Explain the flow of bile and pancreatic juices from their sources into the duodenum of the small intestine. (You can draw a diagram or make a flow chart, if you desire.)
These solutions may offer step-by-step problem-solving explanations or good writing examples that include modern styles of formatting and construction of bibliographies out of text citations and references. Students may use these solutions for personal skill-building and practice. Unethical use is strictly forbidden.1. Describe the functions of the following components of gastric juice.
a. Hydrochloric acid
HCL produced in the gastric juice by the parietal cells or oxyntic cells are associated with anti bacterial function , as well as breaking of the peptide bonds for easy function of for the peptidases , activates pepsinogen to form pepsin.
This is an inactive peptidase produced in the gastric secretion and it is acted on by HCL to convert it into active pepsin. Pepsin then acts on protein to break peptide bonds and form smaller peptides .
c. Pepsin :
This is the active form of pepsinogen and operates only in the acidic medium where it cleaves peptide linkages of amino acids to produce di and tripeptides
d. Intrinsic factor
Intrinsic factor is a glycoprotein produced by the parietal cells of the stomach in the secretion of the gastric juice and is essential in the absorption of vitamin B12 in the ileum...
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