Quiz 16: The Digestive System

Biology

1. Oral cavity, teeth, tongue 2. Pharynx 3. Esophagus 4. Stomach 5. Small intestine 6. Large intestine There are also four accessory organs that add to the digestive system: 7. Salivary glands 8. Liver 9. Gallbladder 10. Pancreas

1. The pyloric sphincter is a muscular band that is positioned between the small intestine and stomach. This structure is located distally from the stomach and extends from the pylorus. The pyloric sphincter's main responsibility is to regulate the flow of chyme between the stomach and small intestine. Thus, the correct answer is (c). 2. Liver cells are otherwise called hepatocytes. They are arranged as series of irregular plates resembling the spokes of a wheel. Hence, the correct match is (k) hepatocytes. 3. Intrinsic factor is a protein that aids our body in the absorption of vitamin B12. Vitamin B12 is essential for the formation and growth of red blood cells. Hence, the correct match is (g). 4. Mesentery is a double layered serous membrane sheet suspending the jejunum and ileum from the posterior wall of the abdomen. Therefore, the correct match is (a). 5. The chief cells are also called gastric zymogenic cells or peptic cells. They are present in the stomach and release pepsinogen. Hence, the correct match is (i). 6. Palate is the roof of the oral cavity or mouth. It is seen in all mammals including humans. The main role of it is to separate the oral cavity from the nasal cavity. Hence, the correct match is (h). 7. Parietal cells are also called oxyntic cells or delomorphous cells. They are a kind of stomach epithelial cells. Their role is to secrete gastric acid that is hydrochloric acid and intrinsic factor. Hence, the correct match is (j). 8. Parasympathetic system controls external organs like digestive organs. For example, the parasympathetic stimulation increases the muscular activity of the digestive system. Hence, the correct match is (d). 9. Sympathetic actions and parasympathetic actions are opposite to each other. For example, sympathetic stimulation inhibits the muscular activity of digestive tract. Hence, the correct match is (f). 10. Peristalsis is a kind of movement that aids in the movement of materials along the digestive tract. Therefore, the correct match is (b). 11. Bile salts are released from the gall bladder. They are used for the emulsification of fats. Therefore, the correct match is (l). 12. Salivary amylase is an enzyme present in the saliva of mammals including humans. It catalyzes the hydrolysis of starch. It breaks down the starch into sugars. Hence, the correct match is (e).

The digestive system has the following functions: 1. Ingestion 2. Mechanical processing 3. Digestion 4. Secretion 5. Absorption 6. Excretion Ingestion refers to food that enters the mouth and digestive tract. Mechanical processing is the physical breakdown of food, beginning with the tongue and teeth and ending in the digestive tract. Digestion is the chemical breakdown of food that can be absorbed by the digestive epithelium. Secretion refers to the release of water, enzymes, acids by the digestive epithelium and accessory organs. Absorption refers to the diffusion of organic molecules, ions, and water into interstitial fluid from the epithelium. Excretion is the last step, where waste products are removed from the body.