CCK

Definition

Cholecystokinin (CCK) is a peptide hormone produced in the small intestine that plays a vital role in the digestive process. It is released in response to the presence of fatty acids and amino acids in the chyme, stimulating the gallbladder to release bile and the pancreas to secrete digestive enzymes. CCK also helps regulate gastric emptying and promotes satiety, thus influencing appetite and food intake.

5 Must Know Facts For Your Next Test

1. CCK is secreted by I cells in the mucosa of the duodenum when fatty acids and amino acids enter the small intestine.
2. In addition to stimulating bile and enzyme release, CCK slows gastric emptying, allowing for better nutrient absorption.
3. CCK also acts on the brain to promote a feeling of fullness, helping to regulate food intake and appetite.
4. The release of CCK can be influenced by factors such as meal composition, particularly meals high in fat or protein.
5. Disruptions in CCK signaling can lead to digestive issues or obesity due to altered appetite regulation.

Review Questions

• How does CCK influence digestion and what are its main effects on the gallbladder and pancreas?
  • CCK significantly influences digestion by stimulating the gallbladder to contract and release bile into the small intestine, which is essential for emulsifying fats. Additionally, it prompts the pancreas to secrete digestive enzymes necessary for breaking down proteins, carbohydrates, and fats. This coordinated response ensures that nutrients are effectively processed and absorbed during digestion.
• Discuss the role of CCK in regulating appetite and how it contributes to feelings of satiety after eating.
  • CCK plays a crucial role in regulating appetite by signaling satiety to the brain once food enters the small intestine. As CCK levels rise after a meal high in fat or protein, it promotes a sense of fullness, thereby helping individuals reduce food intake. This feedback mechanism helps maintain energy balance and can prevent overeating by signaling when enough food has been consumed.
• Evaluate how abnormalities in CCK function could impact overall digestive health and potential links to obesity.
  • Abnormalities in CCK function can severely impact digestive health by disrupting the normal release of bile and pancreatic enzymes, leading to malabsorption of nutrients and gastrointestinal discomfort. Furthermore, if CCK signaling is impaired, it may result in decreased feelings of satiety, encouraging overeating and contributing to obesity. Understanding these links highlights the importance of CCK not just in digestion but also in maintaining healthy body weight.

Related terms

Bile:

A digestive fluid produced by the liver, stored in the gallbladder, and released into the small intestine to emulsify fats for easier digestion.

Pancreatic Enzymes: Digestive enzymes secreted by the pancreas that aid in breaking down proteins, carbohydrates, and fats in the small intestine.

Gastric Emptying:

The process of moving food from the stomach into the small intestine, which is regulated by hormones like CCK to ensure proper digestion.