Liver Function and Metabolism

Bile is a fluid produced by the liver that helps in the digestion of fats. It contains bile salts, cholesterol, phospholipids, bilirubin, and water. Bile salts are crucial for emulsifying fats, which means breaking down large fat globules into smaller droplets (micelles) to increase the surface area for lipase action.

The formation of micelles is essential for fat absorption. Micelles are tiny structures formed by bile salts that transport fats to the intestinal lining for absorption.

Enterohepatic circulation is the recycling process of bile salts. After helping in fat digestion, bile salts are reabsorbed in the ileum (the last part of the small intestine) and returned to the liver for reuse.

The liver converts excess glucose into glycogen (glycogenesis) for storage. When energy is needed, it breaks down glycogen (glycogenolysis) to release glucose into the bloodstream.

The liver synthesizes plasma proteins like albumin and clotting factors. It also deaminates amino acids, converting them into ammonia, which is then transformed into urea for excretion by the kidneys.

The liver plays a crucial role in lipid metabolism. It synthesizes lipoproteins (VLDL, HDL, LDL), cholesterol, and phospholipids, which are essential for cell membrane formation and fat transport in the blood.

The liver detoxifies harmful substances such as alcohol, drugs, and toxins. It converts these substances into less toxic compounds or substances that can be excreted by the kidneys.

The liver produces enzymes and other compounds that promote digestive processes in the small intestine. By producing bile and contributing to other metabolic activities, the liver plays a crucial role in the efficient digestion and absorption of nutrients.

Bilirubin is a yellow pigment produced by the breakdown of red blood cells. The liver converts bilirubin into a water-soluble form that can be excreted in bile.

Jaundice is a condition where bilirubin builds up in the blood, causing the skin and whites of the eyes to turn yellow.

The liver stores vitamins A, D, E, K, and B12, which are essential for various bodily functions, including vision, bone health, immune function, and red blood cell production.

The liver stores iron in the form of ferritin, releasing it when needed for hemoglobin synthesis or other metabolic processes.

Kupffer cells are specialized immune cells in the liver that filter bacteria and debris from the blood, contributing to the body's defense system.

The pancreas is an organ that has both an exocrine and endocrine function, playing a crucial role in digestion and blood sugar regulation.

Pancreatic enzymes like amylase, lipase, and proteases break down carbohydrates, fats, and proteins into smaller molecules that can be absorbed in the small intestine.

The pancreas releases bicarbonate into the small intestine to neutralize the acidic chyme coming from the stomach, protecting the intestinal lining and enabling pancreatic enzymes to work optimally.

Insulin, produced by beta cells in the pancreas, lowers blood sugar by helping cells absorb glucose and storing it as glycogen in the liver and muscles.

Glucagon, secreted by alpha cells, raises blood sugar levels by breaking down stored glycogen in the liver and creating new glucose.

The gallbladder stores and concentrates bile produced by the liver, releasing it into the small intestine to help digest fats, especially after eating fatty meals.

When fatty foods enter the small intestine, the hormone cholecystokinin (CCK) signals the gallbladder to release stored bile into the duodenum, the first part of the small intestine.

Bile emulsifies fats, breaking them down into smaller droplets, increasing their surface area for digestion by pancreatic lipase.

Gallstones form when bile contains too much cholesterol or bilirubin, blocking bile ducts and causing pain and digestive issues.

The liver continuously produces bile, which is stored and concentrated in the gallbladder. When fatty food enters the small intestine, bile is released to emulsify fats, allowing pancreatic lipase to break down the fats further.

The pancreas releases hormones that regulate the release of digestive enzymes and bile, ensuring efficient digestion only when food is present in the digestive tract.

The pancreas releases digestive enzymes (carbohydrases, lipases, proteases) and bicarbonate into the small intestine. Bicarbonate neutralizes stomach acid, creating a suitable environment for enzyme activity.

The liver produces bile, a fluid containing bile salts, which emulsify fats, breaking down large fat droplets into smaller ones. This increases the surface area for lipase action, making fat digestion more efficient.

The small intestine contains villi and microvilli, which increase its surface area for efficient absorption of nutrients. These tiny projections allow for maximum contact with digested food, facilitating the uptake of essential nutrients like fatty acids, glucose, and amino acids.

Hormones like cholecystokinin (CCK) and secretin regulate digestion. CCK stimulates bile release from the gallbladder, while secretin triggers the release of pancreatic enzymes and bicarbonate. Insulin and glucagon from the pancreas control blood sugar levels.

The gallbladder stores and concentrates bile, releasing it into the small intestine during digestion to help with fat breakdown.