Digestive Anatomy
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AP Biology › Digestive Anatomy
Why are villi found in the small intestine, but not in the stomach?
The small intestine uses the villi to increase its surface area and facilitate absorption. Absorption does not occur in the stomach.
The small intestine uses villi to adhere to the food particles entering from the stomach, while the stomach has no need for such adhesion.
The villi allow multiple areas where digestive enzymes can be released by the small intestine. The stomach does not release digestive enzymes.
The villi act in a cilia-like motion and move food down the small intestine. Movement in the stomach is generated by smooth muscle contractions.
Explanation
The villi are helpful in increasing the surface area of the small intestine. This greatly increases the absorptive capabilities of the small intestine. The stomach has no villi, and does not contribute to absorption of macromolecules.
Why are villi found in the small intestine, but not in the stomach?
The small intestine uses the villi to increase its surface area and facilitate absorption. Absorption does not occur in the stomach.
The small intestine uses villi to adhere to the food particles entering from the stomach, while the stomach has no need for such adhesion.
The villi allow multiple areas where digestive enzymes can be released by the small intestine. The stomach does not release digestive enzymes.
The villi act in a cilia-like motion and move food down the small intestine. Movement in the stomach is generated by smooth muscle contractions.
Explanation
The villi are helpful in increasing the surface area of the small intestine. This greatly increases the absorptive capabilities of the small intestine. The stomach has no villi, and does not contribute to absorption of macromolecules.
What is the correct order that a bolus of food will pass through the small intestine?
Duodenum, jejunum, ileum
Ileum, duodenum, jejunum
Duodenum, ileum, jejunum
Jejunum, ileum, duodenum
Jejunum, duodenum, ileum
Explanation
The correct order that the food will pass as is first the duodenum, then the jejunum and finally the ileum. These are all sections or portions of the small intestine, the organ responsible for the vast majority of absorption of nutrients from food before it is passed on to the large intestine, where water, vitamins, minerals, and any other remaining nutrients are absorbed into the body.
What is the correct order that a bolus of food will pass through the small intestine?
Duodenum, jejunum, ileum
Ileum, duodenum, jejunum
Duodenum, ileum, jejunum
Jejunum, ileum, duodenum
Jejunum, duodenum, ileum
Explanation
The correct order that the food will pass as is first the duodenum, then the jejunum and finally the ileum. These are all sections or portions of the small intestine, the organ responsible for the vast majority of absorption of nutrients from food before it is passed on to the large intestine, where water, vitamins, minerals, and any other remaining nutrients are absorbed into the body.
In which region of the upper digestive tract does food transition into chyme?
The stomach
The esophagus
The mouth
The sublingual salivary glands
The liver
Explanation
Chyme is formed during the initial breakdown of food. Food is turned into chyme in the stomach due to the combination of smooth muscle contractions and the chemical action of hydrochloric acid. These processes serve to digest the food both mechanically and chemically.
Which of the following is not secreted by the pancreas into the duodenum?
Pepsin
Bicarbonate
Bile salts
Trypsin
Lipases
Explanation
Pepsin is a protein degrading enzyme that is released by the stomach. All the other choices are released by the pancreas into the duodenum.
In which region of the upper digestive tract does food transition into chyme?
The stomach
The esophagus
The mouth
The sublingual salivary glands
The liver
Explanation
Chyme is formed during the initial breakdown of food. Food is turned into chyme in the stomach due to the combination of smooth muscle contractions and the chemical action of hydrochloric acid. These processes serve to digest the food both mechanically and chemically.
Which of the following is not secreted by the pancreas into the duodenum?
Pepsin
Bicarbonate
Bile salts
Trypsin
Lipases
Explanation
Pepsin is a protein degrading enzyme that is released by the stomach. All the other choices are released by the pancreas into the duodenum.
Removal of the gall bladder from the human body would most likely result in which of the following?
An inability to digest fats properly
An inability to digest carbohydrates properly
An inability to digest proteins properly
An inability to digest starch properly
Explanation
The gallbladder is found underneath the liver. The gallbladder is the storage place of bile, which helps to emulsify fats. Bile is necessary for the digestive system to break down fat. Removal of the gallbladder can result in fat malabsorption, which can present as loose stool.
Removal of the gall bladder from the human body would most likely result in which of the following?
An inability to digest fats properly
An inability to digest carbohydrates properly
An inability to digest proteins properly
An inability to digest starch properly
Explanation
The gallbladder is found underneath the liver. The gallbladder is the storage place of bile, which helps to emulsify fats. Bile is necessary for the digestive system to break down fat. Removal of the gallbladder can result in fat malabsorption, which can present as loose stool.