Absorption
Overview
Digestion has done its work and your food is now a soup of small soluble molecules. Absorption is the moment they finally cross into your blood. It happens mostly in the small intestine, an organ built like no other for one job: soaking up as many molecules as possible, as fast as possible.
In this lesson you will see where absorption happens and learn the clever tricks the small intestine uses to make its surface enormous: millions of finger-like villi, each covered in even tinier microvilli. Extended students will dissect a single villus and meet the capillaries and lacteals that carry the absorbed food away.
Objectives
- State that the small intestine is the region where nutrients are absorbed
- State that most water is absorbed from the small intestine but that some is also absorbed from the colon
- [Supplement] Explain the significance of villi and microvilli in increasing the internal surface area of the small intestine
- [Supplement] Describe the structure of a villus
- [Supplement] Describe the roles of capillaries and lacteals in villi
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Lesson Note
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Lesson Evaluation
Congratulations on completing the lesson on Absorption. Now that youve explored the key concepts and ideas, its time to put your knowledge to the test. This section offers a variety of practice questions designed to reinforce your understanding and help you gauge your grasp of the material.
You will encounter a mix of question types, including multiple-choice questions, short answer questions, and essay questions. Each question is thoughtfully crafted to assess different aspects of your knowledge and critical thinking skills.
Use this evaluation section as an opportunity to reinforce your understanding of the topic and to identify any areas where you may need additional study. Don't be discouraged by any challenges you encounter; instead, view them as opportunities for growth and improvement.
- Most absorption of digested food takes place in the: A. stomach B. small intestine C. mouth D. rectum Answer: B
- Besides the small intestine, some water is also absorbed from the: A. oesophagus B. stomach C. colon D. pancreas Answer: C
- [Supplement] The main role of villi and microvilli is to: A. produce enzymes B. increase surface area for absorption C. store bile D. kill bacteria Answer: B
- [Supplement] Glucose and amino acids are absorbed mainly into the: A. lacteal B. blood capillaries C. bile duct D. stomach Answer: B
- [Supplement] The products of fat digestion are absorbed mainly into the: A. capillaries B. salivary glands C. lacteal D. pancreas Answer: C
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