Lecture 8: The Digestive System pt. 2 Flashcards
What does Metabolic Regulation consist of?
The liver impacting what is available in the blood for use of energy
The liver is one of the two main organs that determines what?
The composition of your blood?
What is the other composition?
Kidneys
What is specific function #1 under Metabolic Regulation?
The liver has a huge role in carbohydrate metabolism.
The organ in your body that has the most impact of regulating blood glucose levels is your liver. Why?
Bc liver decides whether to store glucose or carbohydrates that are coming in from digestive system. Whether to let them go bc we’re at the level we need, or whether we need to break down glycogen and put that glucose in the blood.
What affects the carbohydrates that are passing by?
Insulin and Glucagon.
How can the liver increase blood glucose cells?
- Break down glycogen
- take amino acids and make them into glucose (gluconeogenesis)
Both of those happen under control of what?
Glucagon (which raises blood glucose)
How can we lower blood glucose?
Insulin will stimulate liver to take glucose out of the blood, and store it as glycogen. (NOT throwing it away, we store it until we need it later)
The liver is also important in what?
Lipid metabolism
When your digesting lipids in the small intestine. We need to do things to increase the surface area. But once those things get absorbed into an intestinal cell, what happens?
We get a chylomicron.
What are in chylomicrons?
They have cholesterol, triglycerides, fatty acids in them.
What are chylomicrons made by?
They are made by enterocytes and put them in lactyls.
Where are the chylomicrons going?
They are going into the lymph and wind up in the thoracic duct and into the left subclavian vein.
What does this mean?
That the chylomicron is in the blood and gradually, all these things are going to pass through the liver.
When they get to the liver, the liver is going to do a couple of things to the chylomicron. What will the liver do?
- The liver changes the proteins
- liver removes triglycerides
- add cholesterol
This new thing that the liver just made from a chylomicron is now called a…
Low density lipoprotein
What happens to this LDL?
It’s going to be put in the blood as a system to deliver cholesterol to cells that need OR pick up excess up cholesterol from cells that need to get rid of stuff
Why is LDL bad?
LDL can be incorporated into plaques and arteries and help obstruct a blood vessel.
The proteins will be changed again to a High Density Lipoprotein. What happens to a HDL?
Cells can take or add cholesterol where it will go back into the blood and back into the liver to store cholesterol.
Where are LDL made from?
made in Liver
Where are HDL made from?
made in cells that are not Liver cells
What are enterocytes?
Epithelial cells of the intestine.
The next thing the liver is metabolically involved in is…
(Metabolic Regulation #3)
amino acid metabolism.
The liver monitor if there are too much or too little amino acids of a particular type.
What is one way that the liver can affect amino acid concentration in the blood.
Gluconeogenesis
What happens if we have too much but not enough glucose in the blood?
We convert amino acids in glucose (gluconeogenesis)
What is the metabolic regulation #4?
waste product removal
Hepatocytes that are on either side of the cytosoid are chemically examining whats in the blood moving past them. Things that could be harmful can have a couple of things happen to them…
Hepatocytes might take them in and change them into something else, might take them in and store them, take them and chemically change them and put them in the bile to leave the body.
This is the body can clear some drugs. Some drugs can be take out of the blood from the kidneys. What are the examples of two different drugs.
Tylenol: If take too much, can fry your liver. Bc hepatocytes take it in and try to hold it all and it damages it.
A drug that is not cleared by the liver but cleared by the kidneys is…
Naproxen
The last Metabolic function are…
storing minerals and storing fat soluble vitamins
What does it mean to store fat soluble vitamins?
The fat that we can store in fat soluble vitamins means its possible to accumulate too much of them
What happens when you have too much of a particular mineral or a fat soluble vitamin?
you will store it
What happens when there’s not enough in the blood?
the liver will release some of those storage supplies back into the blood to keep the levels consistent.
What consists of Hematological Regulations?
- Phagocytosis and Ag Presentation
- Synthesis of Plasma Proteins
- Removal of Circulating Hormones
- Removal of Abs (antibodies)
- Removal of storage of Toxins
- Synthesis and Secretion of Bile
What is the main digestion function of the liver?
Production of bile to emulsify fats to digest them
What is the only organ in the body that makes bile?
The liver!
The things we use to emulsify fats to keep them as tiny droplets instead one big fat drop is…
something that has a hydrophobic side to face the fat droplets and a hydrophilic to face the water environment that it’s in.
What gives color to the bile?
Biliverdin and Bilirubin. They are color pigments.
What are one of the things you may see when someone has an obstruction in the bile duct?
They have gray feces.
what give feces the characteristic brown color?
The biliverdin and bilirubin
What shape is the galbladder?
Pear shaped
How long is the galbladder?
7-10 cm long
What are the functions of the gallbladder?
- stores bile
- concentrate of bile
- eject bile
How much bile can the gallbladder hold?
30-50 ml of bile
True or False?
The gallbladder is part of the alimentary canal?
FALSE
The gallbladder is an accessory organ and food SHOULD NOT be found in the gallbladder.
The wall of the gallbladder has a mucosa, musclular layer, and serosa layer. In the mucosa, we have…
rugae
Why do we have rugae in the gallbladder?
We get more surface area to absorb water AND
It’s a muscular bag, it’s going to stretch a little bit. As it gets full, having the rugae will keep the lining from tearing.
Inflammation of the gallbladder is called?
Cholecystitis
Gall stone formation is called what?
Cholelithiasis
You can accumulate stones in the gallbladder where a person gets a flare up of pain. What are some ways?
You can block the cystic duct or the common bile duct. OR pancreatic duct and common bile duct this last little piece to have their contents enter the small intestine through the duodenal papilla. A stone there can cause all sorts of problems bc it can block bile from getting into the intestine, but it can block those pancreatic enzyme precursors that will accumulate enough sometimes to actually have one molecule of trypsinogen to trypsin and now we’re digesting the common bile duct and back up the pancreatic duct. (NOT GOOD)
What can lead to gallbladder removal?
Gall stone formation or Cholelithiasis
What are the risk factors for having gallbladder trouble?
To cause gallbladder trouble:
- fat
- female
- 40
What happens to the control of bile if somebody has their gallbladder removed?
- no storage
- no concentration
- bile that was continually made by the liver is going directly into the small intestine