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Which of the following stimuli activates sensors in the walls of digestive organs?

A. breakdown products of digestion

B. distension

C. pH of chyme

D. all of the above

Answer Explanation:

d) all of the above

- Correct: All of the listed stimuli activate sensors in the walls of digestive organs:

a) Breakdown products of digestion: The presence of breakdown products, such as nutrients and smaller molecules resulting from digestion, can activate sensors in the walls of digestive organs. These sensors help regulate various digestive processes and signal the release of digestive enzymes and hormones.

b) Distension: Distension, or stretching of the walls of the digestive organs, is a stimulus that activates sensors. It occurs as the volume of the digestive tract increases due to the presence of ingested food, and it triggers reflexes that coordinate muscular contractions for propulsion and mixing.

c) pH of chyme: The pH of the chyme (the semi-liquid mixture of food and digestive juices in the stomach and small intestine) is another stimulus that activates sensors. Changes in pH can signal the need for adjustments in the secretion of digestive enzymes and the regulation of gastric and intestinal functions.

Therefore, all of the mentioned stimuli play a role in activating sensors and regulating digestive processes in response to the specific conditions within the digestive organs.

Therefore, the Correct Answer is D.

More Questions on TEAS 7 Science

  • Q #1: Where are most fat-digesting enzymes produced?

    A. small intestine

    B. gallbladder

    C. liver

    D. pancreas

    Answer Explanation

    d) pancreas

    - Correct: Most fat-digesting enzymes, such as pancreatic lipase, are produced in the pancreas. Pancreatic lipase is secreted by the pancreas into the small intestine, specifically the duodenum, where it plays a crucial role in the digestion of dietary fats. Additionally, other enzymes involved in fat digestion, such as pancreatic colipase and phospholipase, are also produced by the pancreas.

    a) small intestine

    - Incorrect: While some fat-digesting enzymes are present in the small intestine, the majority of these enzymes are produced by the pancreas and delivered to the small intestine via the pancreatic duct.

    b) gallbladder

    - Incorrect: The gallbladder stores and concentrates bile produced by the liver, but it does not produce fat-digesting enzymes. Bile stored in the gallbladder contains bile salts, which aid in the emulsification and digestion of fats, but they are not enzymes themselves.

    c) liver

    - Incorrect: The liver produces bile, which contains bile salts that aid in fat digestion by emulsifying large fat globules into smaller droplets, but it does not produce fat-digesting enzymes. The liver also plays a role in lipid metabolism and the synthesis of lipoproteins but does not produce enzymes directly involved in fat digestion.

  • Q #2: During the process of absorption, nutrients from food go from:

    A. the intestines into the bladder

    B. the blood into the organs

    C. the intestines into the bloodstream

    D. the mouth into the stomach

    Answer Explanation

    c. the intestines into the bloodstream

    - Correct: During the process of absorption, nutrients from food pass from the intestines into the bloodstream. After food is broken down into its constituent nutrients through digestion in the stomach and small intestine, these nutrients are absorbed across the lining of the small intestine into the bloodstream. The small intestine is highly specialized for absorption, with villi and microvilli increasing the surface area available for nutrient absorption. Once absorbed into the bloodstream, nutrients are transported to various organs and tissues throughout the body to provide energy, support growth and repair, and maintain overall health.

    a. the intestines into the bladder

    - Incorrect: The bladder is part of the urinary system and is responsible for storing urine produced by the kidneys. Absorption of nutrients does not involve passage into the bladder.

    b. the blood into the organs

    - Incorrect: While nutrients absorbed into the bloodstream are indeed transported to various organs and tissues throughout the body, absorption itself occurs in the intestines, not directly from the blood into the organs.

    d. the mouth into the stomach

    - Incorrect: The mouth and stomach are primarily involved in the initial stages of digestion, including mechanical breakdown of food and the initiation of chemical digestion of carbohydrates and proteins. Absorption of nutrients occurs primarily in the small intestine, not from the mouth into the stomach.

  • Q #3: Which of these cells secrete hormones?

    A. parietal cells

    B. mucous neck cells

    C. enteroendocrine cells

    D. chief cells

    Answer Explanation

    c) enteroendocrine cells

    - Correct: Enteroendocrine cells are specialized cells located in the epithelium of the gastrointestinal tract that secrete hormones. These hormones play various roles in the regulation of digestion, nutrient absorption, and other physiological processes. Examples of hormones secreted by enteroendocrine cells include gastrin, secretin, cholecystokinin (CCK), and ghrelin.

    a) parietal cells

    - Incorrect: Parietal cells are found in the gastric glands of the stomach and secrete hydrochloric acid (HCl) and intrinsic factor, but they do not secrete hormones.

    b) mucous neck cells

    - Incorrect: Mucous neck cells are found in the gastric glands of the stomach and secrete mucus, which helps protect the stomach lining from the acidic environment, but they do not secrete hormones.

    d) chief cells

    - Incorrect: Chief cells are found in the gastric glands of the stomach and secrete pepsinogen, the precursor to the enzyme pepsin, which plays a role in protein digestion. Chief cells do not secrete hormones.