Structure and functions of Liver

1. Human Anatomy and Physiology-II
Digestive system
(Liver)
Mr N.JEGAN
Associate Professor
K.M.COLLEGE OF PHARMACY.
MADURAI.

2. Structure of Liver

3. Liver- Location
It is located in the upper and right side of the
abdominal cavity immediately beneath diaphragm and
above the stomach .

4. Liver -structure
Liver is the largest gland in human body
Weight- 1500 grams ( 2.5% of the total body weight)
Colour- Reddish-brown
Shape- Wedge

5. Liver-Lobes(Hepatic Lobes)
The liver has four lobes.
From Anterior view
1.Right lobe (Large)
2.Left lobe(Small)
From Posterior view
3.Caudate lobe
4.Quadrate lobe

7. Liver-Lobules(Hepatic Lobules)
Hepatic lobule is the structural and functional unit of
liver.
There are about 50,000 to 100,000 lobules in the liver.
The lobule is a honeycomb-like structure and it is made
up of liver cells called hepatocytes (Liver cell).

9. Hepatocytes and Hepatic Plates
 Hepatocytes are arranged in
columns, which form the
hepatic plates.
 Each plate is made up of two
columns of cells.
 In between the two
columns of each plate lies a
bile canaliculus

10.  In between the neighboring plates, a blood space
called sinusoid is present.
 Sinusoid is lined by the endothelial cells.
 In between the endothelial cells some special
macrophages called Kupffer cells are present(It destroy
the microorganism in blood).

11. Portal Triads
Each lobule is surrounded by many portal triads.
Each portal triad consists of three vessels:
1. A branch of hepatic artery
2. A branch of portal vein
3. A tributary of bile duct

12. „Blood supply to Liver
Hepatic artery
It arises directly from aorta and supplies oxygenated blood
to liver.
„Portal Vein
It brings deoxygenated blood from stomach, intestine,
spleen and pancreas. The blood from hepatic artery mixes with
blood from portal vein in hepatic sinusoids.
Hepatic Vein
Central veins from many lobules unite to form bigger veins,
which ultimately form hepatic veins (right and left) which open
into inferior vena cava.

14. Functions of the liver

15. Functions of the liver
1. Metabolism
a)Carbohydrate metabolism
Glucose is converted to glycogen for storage and glucagon
stimulates conversion of glycogen into glucose (Maintain blood
glucose level).
b) Fat metabolism
Stored fat can be converted to a energy
c) Protein metabolism
Deamination of amino acids.
Transamination
Synthesis of plasma proteins

16. 2.Breakdown of erythrocytes and defence against microbes (
Kupffer cells)
3. Detoxification of drugs and toxic substances –
These include ethanol (alcohol), waste products and
microbial toxins. This is because after absorption from the
alimentary tract, they travel in the blood to the liver where
they are largely metabolised so that levels in the blood
leaving the liver and which enters the systemic circulation are
inadequate to achieve therapeutic effects. This is known as
‘first pass metabolism’.
.

17. 3.Inactivation of hormones like Insulin, glucagon,
cortisol, aldosterone, thyroid and sex hormones
4. Production of heat.
5. Secretion of bile
The hepatocytes synthesise the constituents of bile from
the mixed arterial and venous blood in the sinusoids.
These include bile salts, bile pigments and cholesterol .
6. Storage of substances include:
Glycogen
Fat-soluble vitamins: A, D, E, K
Iron, copper
Water-soluble vitamins, e.g. vitamin B12.

18. Bile juice

19. Bile Juice
It secrete from Liver
Stored in gall bladder
Secrete in to Duodenum of Small intestine through
Heapto pancreatic ampulla through bile duct.
Volume : 800 to 1,200 mL/day

20. COMPOSITION OF BILE
Bile contains 97.6% of water and 2.4% of solids.
Solids include organic and inorganic substances

21. Functions of Bile juice
Bile salt
In the small intestine they emulsify fats, aiding
their digestion.
Fatty acids are insoluble in water, which makes
them very difficult to absorb through the intestinal wall.
Bile salts make cholesterol and fatty acids more water-
soluble, enabling both these and the fat-soluble vitamins
(vitamins A, D, E and K) to be readily absorbed.

22. Bile pigment
It is the excretory products in bile.
Bilirubin and biliverdin are the two bile pigments
formed during the breakdown of hemoglobin.