Liver: anatomy & functions

Pavle Peić Tukuljac Mentor: A. Žmegač Horvat

Anatomy

• • Largest gland in the body (1.5 Kg) Under the diaphragm, within the rib cage in the upper right quadrant of the abdomen

Anatomy

• 4 Lobes Major : left and right Minor : caudate and quadrate • Ducts Common hepatic Cystic From gallbladder Common bile Choledochus Joins pancreatic duct at hepatopancreatic ampulla

GALLBLADDER ANATOMY

GALLBLADDER ANATOMY

• Thin-walled green muscular sac • On the inferior surface of the liver • Stores bile that is not immediately needed for digestion • When the muscular wall of the gallbladder contracts bile is expelled into the bile duct

LIVER GALL BLADDER

BILE

• BILE – bile salts, bile pigments, cholesterol, neutral fats, phospholipids and electrolytes • Liver produces 0.5-1 l of bile daily • Bile salts emulsify fats

LIVER GALL BLADDER

LIVER ANATOMY

• • Liver lobules hepatocytes – hexagonal structures consisting of • Hepatocytes radiate outward from a central vein • At each of the six corners of a lobule is a portal triad Liver sinusoids

LIVER ANATOMY

• Hepatocytes produce bile • Bile flows through canals called bile canaliculi to a bile duct • Bile ducts leave the liver via the common hepatic duct

LIVER ANATOMY

80 % 20 %

Functions

•

Metabolic

 Synthesis  Breakdown • •  Other functions – storage of vitamin A,D,B 12 ,F…

Excretion

into bile of waste products from bloodstream

Vascular

– storage of blood

• • • •  •   •   • 

Synthesis

Protein metabolism

Synthesis of amino acids

Carbohydrate metabolism

Gluconeogenesis Glycogenolysis Glycogenesis

Lipid metabolism

Cholesterol synthesis Lipogenesis Production of coagulation factors I , II , V , VII , IX , X and protein C , protein S and antithrombin and XI , Main site of Produces protein red blood cell production insulin-like growth factor 1 – anabolic effects (IGF-1), a polypeptide Production of trombopoetin

Breakdown

• • • • Breaks down insulin and other hormones Breaks down hemoglobin Breaks down or modifies toxic substances (methylation) → sometimes results in toxication Converts ammonia to urea

Other functions

• • Produces albumin , the major osmolar component of blood serum Synthesizes angiotensinogen , the hormone responsible for raising blood pressure activated by renin when (enzyme released when the kidney senses low blood pressure)

References

• • • • • http://en.wikipedia.org/wiki/Liver http://www.youtube.com/watch?v=J0AjkKRxb WM&feature=related http://www.mamashealth.com/organs/liver.as

p www.medterms.com

http://www.youtube.com/watch?v=bx6kj6xLC Zw