Compare the role of Pancreas, Liver and Gallbladder in Digestion

1. Compare the role of
Pancreas, Liver and
Gallbladder in
Digestion

2. Accessory Organs
 An organ that helps with digestion but is not part of the digestive tract.
 The accessory digestive organs are the tongue, salivary glands, pancreas, liver,
and gallbladder.
 Chemical digestion in the small intestine relies on the activities of three
accessory digestive organs the liver, pancreas, and gallbladder.

3. Liver
 In the Greek the word hepar meaning liver. It is the largest gland of the body.
occupying much of the right upper part of the abdominal cavity.
 It consists of both exocrine and endocrine parts.
 The liver performs a wide range of metabolic activities necessary for
homeostasis, nutrition, and immune response.
 The liver is the largest glandular organ of the body. It weighs about 1.36 kg.
 It is reddish brown in color and is divided into main two lobes of unequal size
and shape.

4. Diagram

5. location
 The liver almost fully occupies the right hypochondrium, upper part of the
epigastrium.
 It extends upward under the rib cage as far as the 5th rib anteriorly on the left
side and right 5th intercostal space.
 The liver is V shaped.

6. Composition
 The liver consists of 2 main lobes the right and the left.
 Each lobe is made up of thousands of hexagonally-shaped lobules.
 These lobules are very small. Each lobule is made up of numerous liver cells,
called hepatocytes, take up nutrients, absorbed them and release them into the
bloodstream.
 These lobules are connected to small ducts (tubes) that connect with larger
ducts to form the common hepatic duct.
 Liver tissue is composed of thousands of lobules, and each lobule is made up
of hepatic cells, the basic metabolic cells of the liver.

7. Structure
 The liver is a multilobulated gland.
 The right and left lobes of the liver are separated by a falciform ligament.
 The hepatic lobules are the structural and functional units of the Liver
containing hepatic cells arranged in the form of cords.
 Each lobule is covered by a thin connective tissue sheath called the Glisson’s
Capsule.

8. Structure

9. Structure
 The liver secretes bile which is carried by right and left hepatic ducts.
 From the upper part of the common hepatic duct commences the cystic duct
that ends in the gall bladder.
 The hepatic and cystic duct join and form the bile duct. The bile duct opens
into the pancreatic duct and forms the hepatopancreatic duct.
 The heptic artery carries oxygen rich blood from the aorta (a major vessel in
the heart).
 The portal vein carries blood containing digested food from the small intestine.
 These blood vessels subdivide in the liver repeatedly, terminating in very small
capillaries.
 Each capillary leads to a lobule.

10. Function
 Removal of amino acids from organic compounds.
 Urea formation from proteins and conversion of excess amino acids into urea
to decrease body levels of ammonia.
 The ammonia combines with CO2 in the liver and forms the urea and uric acid.
 Conversion of galactose and fructose to glucose.
 Hepatocytes secrete a non-enzymatic digestive juice called bile. Bile has the
functions emulsion of fats in the digestive tract and absorption of its contents.

11. Function
 It is a complex chemical factory which produces many important substances such as
bile, digestive enzymes, clotting factors, cholesterol, and proteins.
 It is essential in the metabolism of fats, carbohydrates, proteins, and the various
vitamins and minerals.
 It helps control the level of blood sugar and fats.
 It cleanses the blood and detoxifies drugs and potentially harmful chemicals such as
alcohol.
 The liver is a storehouse for blood, vitamins and minerals, and glycogen.
 Synthesis of vitamin A from carotene, and with the Kidneys participation in the
activation of vitamin D.

12. Functions

13. Gallbladder
 In vertebrates the gallbladder is a small organ where bile is stored, before it is
released into the small intestine.
 The gallbladder is a hollow organ that sits just beneath the right lobe of the
liver.
 The gallbladder is a pear-shaped sac lying on the undersurface of the liver.
 It has a capacity of 30 to 50 mL and stores bile, which it concentrates by
absorbing water.

14. Relations
Anteriorly:
 The anterior abdominal wall and the inferior surface of the liver.
Posteriorly:
 The transverse colon and the first and second parts of the duodenum.
Parts of gallbladder
The gallbladder is divided into the fundus, body, and neck.

15. Parts of the gallbladder
 The fundus is rounded and projects below the inferior margin of the liver,
where it comes in contact with the anterior abdominal wall at the level of the
tip of the ninth right costal cartilage.
 The body lies in contact with the liver and is directed upward, backward, and
to the left.
 The neck becomes continuous with the cystic duct, which turns into the lesser
omentum to join the common hepatic duct, to form the bile duct.
 The peritoneum completely surrounds the fundus of the gallbladder and binds
the body and neck to the visceral surface of the liver.

16. Cystic Duct
 The cystic duct is about (3.8 cm) long and connects the neck of the gallbladder
to the common hepatic duct to form the bile duct.
 It usually is somewhat S-shaped.
 The mucous membrane of the cystic duct is raised to form a spiral fold that is
continuous with a similar fold in the neck of the gallbladder.
 The fold is commonly known as the spiral valve.
The function of the spiral valve is to keep
the lumen constantly open.

17. lymphatic drainage
Blood supply:
 The cystic artery, a branch of the right hepatic artery, supplies the gallbladder.
The cystic vein drains directly into the portal vein.
Lymph Drainage:
 The lymph drains into a cystic lymph node situated near the neck of the
gallbladder. From here, the lymph vessels pass to the hepatic nodes along the
course of the hepatic artery and then to the celiac nodes.
Nerve Supply:
 Sympathetic and parasympathetic vagal fibers form the celiac plexus. The
gallbladder contracts in response to the hormone. which is produced by the
mucous membrane of the duodenum on the arrival of fatty food from the
stomach

18. Function
 Storage of bile, and its release into the duodenum when required.
 The normal gall bladder also absorbes small amounts of a loose bile salt
cholesterol compound.
 It regulates pressure in the biliary system by appropriate dilatation or
contraction.
 In fasting state 80% of the bile secreted by liver is stored in the gallbladder.
 It rapidly absorbs sodium Chloride and water concentrating the bile as much as
10 folds.

19. Pancreas
 The pancreas (pan= all , kreas = flesh) is a looks like a flat, elongated tadpole
(18-25 cm) long.
 It lies behind the stomach in the upper abdomen. Its broadest part, called the
head, is attached to the duodenum
 It is a gland that is partly exocrine and partly endocrine.
 The exocrine part secretes the digestive pancreatic juice, and the endocrine part
secretes hormones, eg. Insulin.
 It is soft, lobulated and elongated organ.
 It has a duct running through its length which is joined by many small branches
from the glandular tissue.

20. Pancreas

21. Composition
 The pancreas is composed of two main types of tissue.
 Most of this is known as exocrine tissue which produces pancreatic enzymes a
liter or more every day. which aid digestion.
 Throughout the mass of exocrine tissue are the grape-like clusters of hundreds
of thousands of endocrine cells, known as islets of Langerhans.
 These produce two main hormones which regulate pancreatic secretions and
control blood glucose, the body's fuel.

22. Head of the pancreas
 Head is the enlarged flattened right end of the pancreas, situated within the
curve of duodenum.
 The head has three borders : superior, inferior and right lateral.
 It has two surfaces anterior and posterior.
 It has one process called the uncinate process, which projects from the lower
and left part of the head towards left.

23. The Exocrine Pancreas
 This consists of a large number of lobules made up of small acini, the walls of
which consist of secretory cells.
 Each lobule is drained by a tiny duct and these unite eventually to form the
pancreatic duct, which extends the whole length of the gland and opens into
the duodenum.
 The function of the exocrine pancreas is to produce pancreatic juice containing
enzymes that digest carbohydrates , proteins and fats.
 As in the alimentary tract, parasympathetic stimulation increases the secretion
of pancreatic juice and sympathetic stimulation depress it.

24. The Endocrine Pancreas
 Distributed throughout the gland are groups of specialized cells called the
pancreatic islets (islets of Langerhans).
 The islets have no ducts so the hormones diffuse directly into the blood.
 The endocrine pancreas secretes the hormones insulin and glucagon, which are
principally concerned with control of blood glucose levels.
 Alpha cells produce glucagon.
 Beta cells produce insulin.
 Delta cells produce somatostatin.