Anatomi Fisiologi Ekskresi Empedu Hati (Bilirubin, Garam empedu, Kolesterol, Lesitin)

Summary

The transcript covers the anatomy and physiology of bile production and its role in fat digestion. Bile is produced by the liver and stored in the gallbladder. It is released when fatty food enters the duodenum, triggered by the hormone CCK and the vagus nerve. The key components of bile, including bile salts, cholesterol, lecithin, and bilirubin, help emulsify fats for easier digestion. The process ensures efficient fat metabolism and absorption in the intestines. The transcript also explains the enterohepatic circulation and the impact of bile obstructions on digestion and stool color.

Takeaways

• 🟢 The liver (hepar) is the largest endocrine organ, responsible for producing bile.
• 🟢 Bile is secreted through two main ducts: the right and left hepatic ducts, which join to form the common hepatic duct.
• 🟢 The gallbladder (vesica biliaris) stores bile temporarily and consists of three main parts: the fundus, corpus, and neck.
• 🟢 Bile flows from the gallbladder via the cystic duct, which joins with the hepatic duct to form the common bile duct (ductus choledochus).
• 🟢 The common bile duct merges with the pancreatic duct before releasing its contents into the duodenum through the major duodenal papilla, controlled by the sphincter of Oddi.
• 🟢 Bile is secreted in response to the presence of fatty food in the duodenum, primarily stimulated by the hormone cholecystokinin (CCK) and the vagus nerve.
• 🟢 The components of bile include bile salts, cholesterol, lecithin, and bilirubin, but it does not contain digestive enzymes.
• 🟢 Bile salts play a key role in emulsifying fats and preventing them from clumping together, thereby aiding in fat digestion and absorption.
• 🟢 Lecithin and cholesterol assist bile salts in the emulsification process, improving fat absorption efficiency.
• 🟢 Bilirubin, a breakdown product of red blood cells, gives stool its yellow-brown color. Blockages in bile secretion can cause pale stools and dark urine.

Q & A

What is bile, and where is it produced?

Bile is a substance produced by the liver (hepar), the largest endocrine organ in the body. It is secreted through the right and left hepatic ducts.

What is the function of the gallbladder in bile storage?

The gallbladder (vesica biliaris or vesica fellea) serves as a temporary storage for bile. It consists of parts like the fundus, corpus (body), and neck, and releases bile through the cystic duct.

What happens to bile after it leaves the gallbladder?

Bile from the gallbladder is transported through the cystic duct and combines with bile from the liver to form the common bile duct (ductus choledochus), which then merges with the pancreatic duct to empty into the duodenum.

When is bile released into the digestive tract?

Bile is released into the duodenum when fatty food enters the digestive system, triggering the release of the hormone cholecystokinin (CCK), which signals the gallbladder to contract and release bile.

What is the role of the sphincter of Oddi in bile secretion?

The sphincter of Oddi regulates the flow of bile into the duodenum. It relaxes in response to hormonal and neuronal signals, allowing bile to flow into the digestive tract.

What are the main components of bile?

Bile consists of four main components: bile salts, cholesterol, lecithin, and bilirubin. It is important to note that bile does not contain digestive enzymes.

What is the role of bile salts in fat digestion?

Bile salts help emulsify fats, breaking down large fat globules into smaller droplets, which increases the surface area for digestive enzymes like lipase to act on.

How do bile salts prevent fat droplets from rejoining in the intestine?

Bile salts coat fat droplets with a hydrophilic outer layer, preventing the droplets from coalescing and ensuring effective fat digestion.

What is the enterohepatic circulation of bile?

Enterohepatic circulation refers to the process where bile salts are reabsorbed in the ileum, returned to the liver via the portal vein, and secreted again into the bile, with only about 5% lost in the feces.

What is the function of bilirubin in bile?

Bilirubin, a breakdown product of red blood cells, gives bile its yellow pigment and contributes to the coloration of feces. It does not play a role in digestion.