Digestion is a coordinated process that transforms food into absorbable nutrients and removes waste. It begins before food enters the mouth and depends on the ordered work of organs, muscles, secretions, and sphincters.
The sight, smell, feel, and taste of food can stimulate appetite and prompt the salivary glands to release saliva in anticipation of eating. In the mouth, mastication (chewing) mechanically breaks food into smaller pieces. The tongue helps move food and secretes mucins and lingual lipase, which contributes to lipid digestion.
All flashcards
What is mastication?
Mastication is chewing. It mechanically breaks food into smaller pieces in the mouth, helping prepare it for swallowing and further digestion.
What does peristalsis do?
Peristalsis is a series of involuntary, wave-like muscular contractions that move food and digestive contents through the esophagus and intestines.
What is chyme, and where is it formed?
Chyme is the partly digested mixture produced when the stomach churns food and combines it with gastric secretions.
How do the liver and gallbladder contribute to digestion?
The liver produces bile. The gallbladder stores and concentrates it, then bile is released into the duodenum to assist digestion.
How do the anal sphincters differ in their roles?
The internal anal sphincter relaxes reflexively in response to rectal stretching. The external anal sphincter is generally under conscious control and helps a person decide when to pass stool.
Quiz questions
What is the main role of intrinsic factor produced by stomach parietal cells?Answer: It is necessary for vitamin B₁₂ absorption.
For people with celiac disease, which dietary component is an important trigger?Answer: Gluten
Which esophageal condition may be associated with food allergies?Answer: Eosinophilic esophagitis
What may decreased pancreatic digestive enzyme production in older adults reduce?Answer: Protein and fat digestion
Why can nutrient-dense foods be useful when an older adult eats less?Answer: They provide essential nutrients in fewer calories.
Based on Nutrition for Nurses by Emerald Charity Bilbrew, Jody Vogelzang, Kelli Whittington (OpenStax), licensed CC BY 4.0. Adapted into a summary, flashcards and quizzes.