Spectrum Biology - September 2016

Large Intestine, Rectum and Anal

Canal

 The large intestine is about 1.5 m long, beginning at the

caecum in the right iliac fossa and terminating at the

rectum and anal canal deep in the pelvis.

 The rectum is slightly dilated part of the colon, which is

about 13 cm long. It leads from the sigmoid colon and

terminates in the anal canal.

 The anal canal is a short canal about 3.8 cm long in adult and

leads from the rectum to the exterior.

Pancreas

 It is a pale-grey gland weighing about 60 gms. It is about

12-15 cm long and is situated in the epigastric and left

hypochondriac regions of the abdominal cavity.

 It is both an exocrine and endocrine gland.

Liver and Gall Bladder

 The liver is the largest gland in the body, weighing between

1-2.3 kg. It has four lobes. The two are larger right lobes and

smaller wedge-shaped left lobes. The other two, the caudate

and quadrate lobes, are areas on the posterior surface.

 The gall bladder is a sac like structure located on the

inferior surface of the liver. Its principle function is

the storage and concentration of bile secreted by

liver.

Biliary Tract

 The right and left hepatic veins join to form the

common hepatic duct just outside the portal fissure.

 The cystic duct joins it and together they form the

common bile duct.

Lactose Intolerance

Lactose or milk sugar is a disaccharide composed of glucose and

galactose. Ingested lactose must be digested before it can be

absorbed. It is accomplished by the action of lactose enzyme. This

enzyme is found only in juvenile mammals, except in some

humans of European descent.

These people inherit a dominant gene that allows them to

produce lactose after childhood. In non-western cultures most

adults lack the gene and synthesise less intestinal lactose.

Decreased lactose activity is associated with a condition known

as lactose intolerance. If a person with lactose intolerance drinks

milk or eats dairy products, diarrhea may result.

Thus, it can be concluded that alimentary canal is a

unique macromolecule splitting tool, which shows

diversity among organisms of different groups.

Common

hepatic artery

Coeliac artery

Aorta

Body and tail

of pancreas

Hepatopancreatic Pancreatic duct

ampulla

Interior of

duodenum

Gall

bladder

Common

bile duct

Cystic duct

Hepatic duct

Portal vein

The pancreas in relation to the duodenum and biliary

tract. Part of the anterior wall of the duodenum removed

Quadrate lobe

Falciform ligament

Bile duct

Hepatic

artery

L. lobe

Gastric

impression

Caudate

Portal lobe

Inferior vena cavavein

R. adrenal gland

impression

R. renal impression

Duodenal impression

Colic impression

R. lobe

Gall

bladder

The liver turned up to show the posterior surface

Bile from liver

L. hepatic duct

Cystic duct

Hepatic duct

Cut open

Common

bile duct

Pancreatic duct

Head of

pancreas

Hepatopancreatic

sphincter

Hepatopancreatic

ampulla

Duodenum

Gall bladder

cut open

R. hepatic duct

Direction of the flow of bile from the liver to the duodenum

Hepatic

flexure of colon

Spleenic

flexure of colon

Transverse

colon

Descending

colon

Sigmoid colon

Rectum

Ascending colon

Caecum

Vermiform

appendix

Parts of the small intestine and large intestine (colon)

Terminal end of ileum

ileum

Jejunum

Duodenum

Pancreas