Cholecystokinin

Definition

Cholecystokinin (CCK) is a peptide hormone produced by I-cells in the duodenum and jejunum of the small intestine. It plays a crucial role in the regulation of digestion, particularly in the stimulation of the gallbladder to release bile and the pancreas to secrete digestive enzymes.

5 Must Know Facts For Your Next Test

1. Cholecystokinin is released in response to the presence of fats and proteins in the small intestine, stimulating the gallbladder to contract and release bile.
2. The release of bile from the gallbladder helps emulsify and break down fats, aiding in their absorption in the small intestine.
3. Cholecystokinin also stimulates the pancreas to secrete digestive enzymes, further enhancing the digestion and absorption of nutrients.
4. In addition to its role in digestion, cholecystokinin acts as a satiety signal, helping to regulate appetite and food intake.
5. Imbalances in cholecystokinin levels have been linked to various gastrointestinal disorders, such as gallstones and pancreatitis.

Review Questions

• Describe the role of cholecystokinin in the digestive system processes and regulation.
  • Cholecystokinin (CCK) is a key hormone in the regulation of digestion. It is released by I-cells in the small intestine in response to the presence of fats and proteins. CCK stimulates the gallbladder to contract and release bile, which helps emulsify and break down fats, aiding in their absorption. CCK also triggers the pancreas to secrete digestive enzymes, further enhancing the digestion and absorption of nutrients. Additionally, CCK acts as a satiety signal, helping to regulate appetite and food intake.
• Explain how cholecystokinin relates to the accessory organs involved in digestion, such as the liver, pancreas, and gallbladder.
  • Cholecystokinin (CCK) plays a crucial role in the functioning of the accessory organs involved in digestion. It stimulates the gallbladder to release bile, which is produced by the liver and stored in the gallbladder. Bile aids in the digestion and absorption of fats in the small intestine. CCK also triggers the pancreas to secrete digestive enzymes, further enhancing the digestive process. The interplay between CCK and these accessory organs, the liver, pancreas, and gallbladder, is essential for the efficient breakdown and absorption of nutrients in the digestive system.
• Analyze the potential implications of imbalances in cholecystokinin levels on the overall functioning of the digestive system.
  • Imbalances in cholecystokinin (CCK) levels can have significant consequences for the digestive system. Decreased CCK levels may lead to reduced bile secretion from the gallbladder, impaired fat digestion, and potentially the formation of gallstones. Conversely, excessive CCK production can overstimulate the gallbladder and pancreas, leading to conditions like gallbladder disease and pancreatitis. Additionally, CCK's role in regulating appetite and food intake means that imbalances in this hormone can contribute to issues like overeating, obesity, and associated metabolic disorders. Understanding the importance of maintaining proper CCK levels is crucial for the overall health and functioning of the digestive system.

Related terms

Gallbladder: A small, pear-shaped organ located beneath the liver that stores and concentrates bile, a digestive fluid produced by the liver.

Pancreas: An organ located behind the stomach that produces enzymes and hormones, including insulin and glucagon, which are essential for digestion and regulating blood sugar levels.

Bile: A yellowish-green fluid produced by the liver and stored in the gallbladder. Bile aids in the digestion and absorption of fats in the small intestine.