Liver: anatomy & functions

Pavle Peić TukuljacMentor: 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 rightMinor: caudate and

quadrate•Ducts

Common hepaticCystic

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 – hexagonal structures consisting of hepatocytes • 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 SynthesisBreakdownOther functions – storage of vitamin A,D,B12,F…• Excretion of waste products from bloodstream

into bile• 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 XI,

and protein C, protein S and antithrombin• Main site of red blood cell production• Produces insulin-like growth factor 1 (IGF-1), a polypeptide

protein – anabolic effects• 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 when activated by renin (enzyme released when the kidney senses low blood pressure)

References

• http://en.wikipedia.org/wiki/Liver • http://www.youtube.com/watch?v

=J0AjkKRxbWM&feature=related• http://

www.mamashealth.com/organs/liver.asp• www.medterms.com• http://www.youtube.com/watch?v

=bx6kj6xLCZw