Physiology of the liver

Cells

Liver contains hepatocytes, endothelial cells and Kupffer cells.

  • Hepatocytes perform the functions of the liver for conjugation etc.
  • Endothelial cells line the sinusoids and they have very large pores up to 1 μm in diameter. Between the hepatocytes and the endothelial lining of sinusoids is the Space of Disse or perisinusoidal space.
  • Kupffer cells act as macrophages

Bile production

The liver produces bile at between 6 to 1000 ml/day and excretes it through the bile cannaliculi which are drained into the bile ducts and then into the cystic duct and gall bladder or directly into the duodenum through the common bile duct. Hence part of the test of liver function includes the production of bilirubin. Also the liver takes part in the conjugation of substances some which then become less toxic for the body. If it fails then it is unable to conjugate these substance which then enter the blood stream and act as toxicants and toxic agents which then cause hepatic encephalopathy.

Blood function of the liver

The liver receives large amount of blood from both the hepatic artery and the portal vein.  It is able to receive the blood and its content to include large amounts of hormones from the gastrointestinal tract which helps the digestive and other metabolic functions of the liver, failing which the liver undergoes fatty degeneration. The liver also functions as reservoir of blood. It also has large amounts of lymphatic flow through the spaces of Disse. High amount of hepatic vascular pressures lead to formation of ascites.

Regeneration:

Liver is capable of regenerating itself after damage or injury or infection as in hepatitis. Hepatocyte growth factor is the main factor which stimulates the cell division in the hepatocytes that lead to regeneration. The process of regeneration ends when the liver has reached its full size.

Liver kuppfer cell macrophagic system

The liver functions as a blood cleansing system by which its macrophages called Kupffer cells remove debris and foreign bodies, mostly colonic bacilli from the blood system. They also breakdown red blood cells and metabolic end product of hemoglobulin breakdown  which is bilirubin. Liver assists the excretion of bilirubin into bile for its elimination and also the excesses of cholesterol.

Metabolic functions of liver

Liver takes part in carbohydrate metabolism, fat and protein metabolism

Carbohydrate metabolism

Carbohydrate metabolism in the liver has the following parts

  • Glycogen storage in large quantities
  • Gluconeogenesis
  • Conversion of metabolites of carbohydrate metabolism to many compounds
  • Conversion of fructose and galactose to fructose

Fat metabolism

Protein metabolism

  • Formation of plasma proteins
  • Amino acid deamination
  • Urea synthesis which causes removal of ammonia from body fluids
     

Liver physiological measurements

Portal hypertension

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


    

Liver lobule. Click to restart

 
Liver physiology

 

 

 

 

 

 

 

 

 

 

Liver and stomach bed Anterior liver Visceral surface liver Superior liver
Inferior liver Posterior liver Visceral surface liver Fresh liver-diaphragmatic surface
Fresh liver-diaphragmatic surface Fixed liver- diaphragmatic surface Postportem liver-diaphragmatic surface Postportem-liver in greater sac
Diagram of functional lobes Diagram of functional lobes Liver and costal margin Diagram- liver, stomach etc

 

 

 

Li  

 

 

 

 

Items

Introduction

Cell biology

Embryology

Histology

Gross anatomy

Lymphatic drainage

Organ integration
Clinical anatomy

Quiz

Dissector
Physiology

Biochemistry

Pharmacology

Chemical Pathology

Anatomical Pathology

Imaging

Medicine

Surgery

Portal vein
Liver phsiology
Portal hypertension
Portocaval anastomoses
Portosystemic obstruction
Portal venogram

Hepatic encephalopathy
Portosystemic shunt

Schistosomiasis

Main Subject Course Links

eAnatomy eAnesthesia eBiochemistry eChemical pathology eCommunity Health
eDermatology eENT eGynecology eHematology eImaging
eMedicine eMedical microbiology eObstetrics eOphthalmology ePathology
ePediatrics ePharmacology ePhysiology ePsychiatry    eSurgery/eOrthopedics
eLab eOSCE eProcedures eInvestigations eSchool/Videopage
eOrgans eLocator Anatomy Museum eDissector eFractures/Dissect-it-yourself
All diseases eClerking eTreatment eDoctor ePatient

 

Electronic School of Medicine
Creator: Oluwole Ogunranti