digestive system 4

where are the 2 hepatic ducts

One on left side and one on right side of liver

What do the hepatic ducts form

The common hepatic duct

What is the common hepatic duct

A region the gallbladder empties its contents

what is the gallbladder responsible for

The storage of bile that is made by the liver which is important for breakdown of lipids

what happens to bile after it is stimulated

It is released along common duct and merges into common hepatic duct. It then leads down into duodenum into sphincter of office and region where pancreatic duct feeds into as well

what is down the middle of the pancreas

The pancreatic duct which is reponsivlr got release of pancreatic juices

where does the pancreatic duct

Responsible for the release of pancreatic joins the common bile duct which is the ampulla of vater

Why is the pancreas a dual organ

It desecrates hormones in an exocrine fashion as tissue around pancreas are islets of langerhan which create hormones

The pancreas also is an exocrine gland and secretes hormones where they exit body by Aciner cells which secretes enzymes and duct cells which secretes bicarbonate rich fluid and pancreatic cells

Where is the pancreas

Below stomach and is an accessory organ

It’s connected to the small intestine by pancreatic duct which joins bile duct

What are the hormones that play a role in secretions released by pancreas

Secretin and CCK. During intestinal phase of gastric secretion there is a release of chime the endocrine cells within epithelial lining of duodenum will signal back to cells in stomach and secretin and CCK will travel in bloodstream to stomach and once they reach stomach they signal to gastric cells to stop releasing HCL and pepsin.

They also play a key role in pancreatic secretions as once they are released in G cells in duodenum they release pancreatic juice

What is pancreatic juice

Exocrine cells are responsible for release of pancreatic juice into duodenum

It aids in transplantation of chime through small intestines

What is pancreatic juice composed of

water, ions(sodium, potassium) and sodium bicarbonate to buffer fluid arriving from stomach which raises PH to 9 alkaline

How much pancreatic juice do we secrete

1.2-.1.5 a day

Name of enzymes released in pancreas

Trypsin

Chymotrysin

Carboxypeptidase

Elastase

What is pancreatic amalyse

Break down carbohydrates if there is undigested starch into maltose.

Also converts maltose, sucrose and lactose into monosaccharides

Maltose forms two glucose

Sucrose form glucose and fructose

Lactose has glucose and galactose

This is done by three key enzymes mulrase, sucrose and lactate found in cell membrane of intestinal epithelial

Absorbed by active transport into blood

What does pancreatic fluid include

Pancreatic fluid responsible for breakdown of tryglycerol to fatty acid and glycerol

how do the large soluble get broken down into smaller pieces first

By bile salts

What happens to the bile salts

They interact with lipid droplets and the hydrophobic parts of blue intergrate with lipid droplets to make them smaller so they can defuse across epithelial cell into lymphatic system

Where is bile produced

In the liver

How much bile is produced

Around a litre everyday

What is the PH like of bile

Neutral 7.6-8.6

Where is bile stored

in gallbladder pouch

What are secretions of bile made up of

Bile salts that are responsible for breakdown of fats

Cholesterol

Ions- for absorption and cellular functions

Bile pignments (bilirubin)

What is the role of bile acid

Emulsifies fats that can be more easily digested and absorbed by sodium and potassium ions

What if someone doesn’t have a gallbladder

The bile goes down to duodenum

What does the gallbladder do

It stores bile that has been produced by liver to emulsify lipids

What is the gallbladder capacity

100ml

What causes bile to come out bile duct into duodenum

The endocrine cells in duodenum detect chime and CCK is produced which causes gallbladder to contract and bile comes out bile duct

What are the three regions of the small intestines

The duodenum- where chime gets into

Jejunum

Lleum

How long is the small intestine in length

6m it’s the longest part of GI TRACT

What are vili and microvilli for

To maximise the surface area to absorb as much of the nutrients as we can

what else is villi useful for

It has a rich nervous, blood and lymphatic supply

Which part contains microvilli

An individual epithelial cell of the lining of small intestines to maximise surface are and contact of chime

What happens in mucosa layer

We have rich blood supply coming in

What is lymphatic supply useful for

Absorbtion of chloride microns across epithelial lining

What is nerve supply

For Movement of villi

What is bruners gland responsible for

Producing mucous that gets into lumen to lubricate environment

How does the large intestines connect to small intestines

Through illeoceal sphincter

What are the parts of the large intestines

The Cecum which leads to ascending colon, transverse colon, descending colon, sigmoid colon then recrum

What is the mucosal layer like in the large intestine

Contains simple columnar cells with intestinal glands in between

What are in intestinal glands

Goblet cells for production of mucous

What is the muscularis layer like in the large intestine

Contains longitudinal muscle that thickens to form three bands called taenia coli which causes formation of Haustra creating bulges for definition

What is the function of small intestines

Concentrate waste by squeezing out moisture from chime to faeces

Where is faeces stored

In haustra until we need the toilet