tailieunhanh - Cracking the toefl ibt 2008 part 39

Tham khảo tài liệu 'cracking the toefl ibt 2008 part 39', ngoại ngữ, toefl - ielts - toeic phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 29. The word OMSB in the passage is closest in meaning to A remembered B surprised C invented D motivated Hwwimm In the Body Up to the beginning of the twentieth century the nervous system was thought to control alt communication within die tody and the resulting Integration of behavior. Scientists had determined that nerves ran essentially on electrical impulses. These impulses were brought to to the HI thought emotion movement and internal processes such as digestion However experiments by William Bayliss and Erpest Sterling on the. chemical secretin which is produced in the small intestine when food enters the stomach eventually challenged that view. From the small intestine secretin travels through the bloodstream to the pancreas There stimulates the release Cit digestive chemicals. In this fashion the intestinal cells that produce secretin ultimately regulate the production of different chemicals in a different organ the ocreas. Such a coordination of processes had bean thought to require contra by the nervous system Bayliss and Starling showed that it could occur through chemicals alone. This discovery NM Sterling to coin the term hormone to rater to secretin taking it from the Greek word hornan meaning to excite or to set in motion. A hormone is a chemical produced by one tissue to make things happen elsewhere. As more hormones were discovered they were categorized primarily according to the process by which they operated on the body. Some glands which make up the endocrine system secrete hormones directly into the bloodstream Such glands include the thyroid and the pituitary. The exocrine system consists of organs and glands that produce substances that are used outside the bloodstream primarily for digestion. The pancreas is one such organ although It secretes some chemicals into ths blood and this is also part of tto endocrine system Much has teen teamed about hormones since their discovery Some play sudi rales in regulating todiiy processes or behavior .