The TOEFL is a rest thai assesses your proficiency in the type of English used in an academic environment* The test is administered on rhe Internet, which we'll explain in more detail on page 6. | 38. Look at the four squares that indicate where the following sentence could be added to the passage. The body is a complex machine however and recent studies have called into question the wisdom of essentially trying to fool its systems into believing they aren t aging. Where would the sentence best fit Click on a square to add the sentence to the passage. Here on this practice test circle your answer below. A Square 1 B Square C Square 3 D Square 4 Hormones in the Body Until the beginning of the twentieth century the nervous system was thought to control all communication within the body and the resulting integration ol behavior. Scientists had determined that nerves ran. essentially on electrical impulses These impulses were thought to be the engine for thought emotion movement and internal processes such as digestion However experiments by William Baybss and Ernest Starling on the chemical secretin which is produced m 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 it stimulates the release ol digestive chemicals. In this tashioo. the intestinal cells that produce secretin ultimately regulate the production ot different chemicals in a different organ the pancreas Such a coordination ot processes had been thought to require control by the nervous system Bayliss and Starling showed that it could occur through chemicals alone This discovery spurred Starling to coin the term hormone Io refer to secretin taking it from the Greek word homwn. meaning to excite or Io 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 .
