This set of Clinical Science Multiple Choice Questions & Answers (MCQs) focuses on “Anatomy and Physiology of G.I.T – 1”.
1. What is the pH of an empty stomach?
Explanation: The stomach produces acid to destroy any harmful substances and microbes that may enter the body through food. It also produces pepsin which starts the digestion of proteins. Pepsin requires an acidic medium to work. When the stomach is full, the acidity may fall to pH 4.
2. islets of Langerhans are found in __________
Explanation: Pancreas is one of the organs which has both endocrine and exocrine functions. The islets of Langerhans are dense clusters of cells which act as the endocrine systems of the pancreas. They produce various hormones for the regulation of glucose the most important one being insulin.
3. Digestion of fats begins in _______
Explanation: Fats are in the form of large globules and so because of their small surface area, they cannot be digested easily. When the food in the form of chyme enters the duodenum of the small intestine, it comes in contact with the bile salts which break fat into smaller globules. The pancreatic juices contain enzymes for the digestion of fats.
4. Chewing of food is called ______
Explanation: The chewing process is called as mastication. The incisors bit and cut, the canines rip, the premolars and molars chew. Since the molars and premolars are at the back of the mouth, they receive the most muscle and skeletal support. These teeth cause mastication.
5. Which organ contributes the most enzymes and hormones towards digestion?
Explanation: The major sites of digestion are mouth, stomach, duodenum and ileum. However, the duodenum does not secrete any digestive juices. It is simply the receiving site for the incoming food from the stomach and the secretions from the bile duct. The bile salts are produced in the liver but it is finally the pancreas that brings in juices for the digestion of proteins, fats and carbohydrates. After digestion is done and food has been absorbed by the blood, it is the pancreatic hormonal secretions that help in regulating the amount of glucose in the blood.
6. The movement of an esophagus to help the food down the GI tract __________
Explanation: After chewing, the tongue rolls the food in the form of a bolus and shifts the food to the oesophagus. The walls of the esophagus contract and relax and slowly allow the food to move down and enter the stomach. This allows the food to enter the stomach slowly and avoid and acid splash. This movement is peristalsis.
7. The three different cells found in the stomach
a) Chief cells, renal cells, nephron
b) Renal cells, mucous cells, hepatic cells
c) Nephrons, hepatic cells, parietal cells
d) Chief cells, parietal cells, mucous cells
Explanation: Chief cells are also called as zymogen cells as they secrete enzymes. Parietal cells are oxygentic cells and they secrete HCl to destroy the microbes and any other harmful substances. The mucous cells secrete mucous to protect the walls of the stomach being harmed by the HCl. It also allows for the smooth passage of food.
8. The band of muscles guarding the two openings of the stomach towards the esophageal and intestinal sides is called as _______________
a) pyloric sphincter and pyruvic sphincter
b) diaphragm and pyloric sphincter
c) cardiac sphincter and lower sphincter
d) cardiac sphincter and pyloric sphincter
Explanation: The sphincters are basically a band of muscles that regulate the opening and closing of any opening in the body. The sphincter muscles towards the esophagus are called the cardiac sphincter because they are close to the heart or the lower sphincter because it brings the food down. The opening towards the intestine is called the pylorus and the muscles guarding them are the pyloric sphincter.
9. A vestigial organ for humans found near the junction of the small and large intestine is the _______
b) Nictitating Membrane
Explanation: In herbivores, especially like cows, the appendix produces enzymes that help in the digestion of cellulose, something that the human stomach cant do. Thus, this is a vestigial organ that is present at the junction of the large and small intestine.
Sanfoundry Global Education & Learning Series – Clinical Science.
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