Quiz 3: The Human Body: a Nutrition Perspective
The stomach guards itself from being digested by enzymes and other acid by the following ways: 1. A thick layer of mucus lines the stomach and protects it. 2. The enzymes and acids are released only by the hormonal action o gastrin. Gastrin releases only at the time of eating. 3. With the increase in acid production in the stomach, hormonal control causes acid production to taper off. Hence the correct option is (b). Stomach protects itself through the mucus lining and hormonal control of acid production. Thus options 'a', 'c', and'd' are irrelevant.
Different organs aggregate to form body systems that have an entire chain of functions. The entire human body comprises of twelve body systems that include cardiovascular, lymphatic, nervous, endocrine, immune, digestive, urinary, integumentary, skeletal, muscular, reproductive and respiratory systems. Each of them has a specialized function of its own. 1. The cardiovascular system is responsible for pumping blood to all parts of the body and blood contains nutrients. Thus, cardiovascular system is responsible for the transport of nutrients to all parts of the body. 2. The lacteals are part of the lymphatic system. They are present in the intestinal villi and help in the absorption of fat form the intestines to the circulatory system. 3. The nervous system controls mechanisms related to hunger and satiety. The sensation of pain and its response is also attributed to the nervous system. 4. The endocrine system plays an important role in the absorption of various nutrients in the body. For example, the anti-diuretic hormone, secreted by the posterior pituitary, regulates the release of water form the nephrons. Insulin, secreted by the pancreas, binds to sugars and facilitates their absorption. 5. The immune system is related to removal of toxins and pathogens entering the body through various routes, including through food.6. The digestive system acts as the primary site where the action of breaking down complex nutrients into simpler substances takes place. 7. The urinary system is chiefly concerned with the removal of waste products resulting after the complete absorption of food in the body. 8. The skin, which is part of the integumentary system, helps in the regulation of water in the body. It also helps in maintaining the water balance of the body through the regulation of sweat from the body. 9. The skeletal system is a reservoir of calcium. It stores 99% of all calcium in the body. It provides the necessary framework for support, facilitates locomotion, and protects the internal organs, 10. The mechanism of peristalsis is caused by the muscles of the gastrointestinal tract. Together they contraction and relax in rhythmic pattern to propel food from the mouth to the anus. 11. The respiratory system provides oxygen that is utilized by all cells of the body for various processes including that for releasing energy. It also helps in the release of carbon dioxide from the body. Excess of carbon dioxide in the body causes hyperacidity. 12. The reproductive system, apart from the evident function of enabling the activity of reproduction, is also the seat of nutrition to the fetus. The placenta that surrounds the fetus provides nutrition from the mother's body.
Sphincters are muscular bandlike structures placed at the interface of openings. They regulate the flow of contents from one side of the opening to the other. b.The sphincter located between the stomach and duodenum is called pyloric sphincter and it helps in regulating the flow of food from the stomach to the small intestine. Hence, option "b" is incorrect. c.The sphincter between the ileum and cecum is referred to as the ileocecal valve. Relaxation of the ileocecal valves helps in propelling the food from the small intestine to the large intestine. Hence, option "c" is also incorrect. d.The sphincter between the colon and the anus is called the anal sphincter. It prevents the rectum from emptying the contents involuntarily. Hence, option "d" is also incorrect. a.The sphincter between the stomach and esophagus is called the lower esophageal sphincter. it prevents the food from entering back from the stomach to the esophagus. Hence, option "a" is the correct option. Answer: