Pancreas and Liver Flashcards
When a drop in duodenal pH is detected - as chyme enters - what is released by cells in the duodenum? What effect does the secretion of this substance have?
Secretin is release which stimulates the release of bicarbonate rich secretions from the pancreas which help raise the pH of duodenal contents
What structures enter and exit via the porta hepatis?
Hepatic portal vein, hepatic arteries and hepatic bile ducts
In the porta hepatis which structures are transferring substances into the liver and which structure out?
In - hepatic portal vein and hepatic arteries
Out - hepatic bile ducts
The hepatic veins drain the liver into…
Inferior Vena Cava (IVC)
When is the common bile duct formed?
When the common hepatic duct joins the cystic duct
Where does the pancreas connect to the GIT to transfer its exocrine secretions?
2nd part of the duodenum (descending portion)
What controls the opening of the pancreatic and common bile ducts into the duodenum?
muscular sphincter of Oddi
How would you describe the properties of chyme as it leaves the stomach?
Hypertonic
Acidic
What is chyme?
A semi-fluid mixture of partially digested food
Why is chyme hypertonic?
Walls of the stomach are not permeable to water. Normally water would flow into an area of high solute like the lumen of the stomach to dilute it
What is the primary function of bile?
To facilitate lipid digestion - helps disperse lipids in solution, creating a larger surface area for lipase to work on
What are bile acids converted to?
Bile salts
What is the name of the functional unit of the liver?
the acinus
The functional unit of the liver, the acinus, is divided into 3 zones. Zone 3 is more at risk of ischaemic damage than zone 1. Why?
Greater distance from where blood (arterial and venous) enters the acinus at the portal triad. If there is a sustained drop in blood entering the acinus then zone 3 cells will face greater necrosis from ischaemia than zone 1 cells
Which cell types make up zones 1,2 and 3 of the liver acinus?
Hepatocytes - the main cell of the liver
When fatty acids and amino acids are detected in the duodenum, what GI hormone is released that stimulates the pancreas to produce digestive enzymes?
Cholecystokinin (CCK)
What is the role of CCK in digestion?
It is secreted in response to the presence of amino acids and fatty acids in the duodenum.
It stimulates the pancreas to secrete enzymes, contraction of the gallbladder and relaxation of the sphincter of Oddi
What stimulates the secretion of secretin?
Drop in duodenal pH
What is the role of secretin in digestion?
It is secreted in response to a drop in duodenal pH and stimulates the release of a bicarbonate rich pancreatic secretion
What is the structural unit of the liver called?
Lobule
What is the name of the structure in the centre of a lobule?
Central vein
What is the name of the structure at the vertices of a lobule?
Portal triads
How is the structure of the liver lobule formed?
Invaginations of the liver capsule
What abdominal ligament connects the liver to the anterior abdominal wall?
Falciform ligament