Lecture 15 - Liver & Gallbladder Flashcards
General Function of Gallladder?
Store and Concentrate bile
What is the organizational pattern of the liver?
- Hexagonal Lobules
- Portal Triads at connections
- Cords of hepatocytes surround a central vein
What type of capillaries are in the liver?
Sinusoid
What is the flow of blood in the liver?
- Mesenteric and other artieries
- GI tract
- Hepatic portal vein (along w/ hepatic artery)
- Back to heart
Where do sinusoids drain into?
Central vein
What cells make up the linear cords?
Hepatocytes
Where does blood from the GI tract go?
ALL of it goes to the liver
How does the liver prevent you from becoming hyperglycemic?
The liver is able to remove glucose from hepatic portal blood (w/ the aid of insulin, and gets stored as glycogen)
What is the general function of the liver?
Take up nutrients during feeding and release nutrients during fasting
How do substances easily get into the blood or liver sinusoids?
- Endothelial layer has fenestrations
2. No basement membrane
How does the liver help digest lipids?
Hepatocytes secrete bile which emulsifies fat in the intestine
Where is bile made?
- It is in the hepatocytes
2. Bile canaliculi run between hepatocytes are are surrounded by tight junctions
What is the path of bile?
- It is produced by heptocytes, travels to canaliculi to a branch of the bile duct and then to the duodenum
- It goes in to opposite direction as the flow of blood
Besides bile acids, what else is in bile?
- Cholesterol and other lipids
- Drugs/Toxins/ Other liver metabolites (excrete substances from the body)
- Biliruben
Where does biliruben come from?
- Macrophages in spleen destroy old/deformed RBC
- Metabolizes heme
- Now it is biliruben (yellow pigment)
- Goes into bile
- Biliruben is changed to biliverdein (green pigment)
- Travels into the duodenum
What happens to bilirubin in the duodenum?
- Goes to the colon
2. Becomes stercobilin (brown pigment)
What happens if bile is prevented from leaving the liver?
- Can’t excrete biliruben (jaundice)
- Pale or grey stool (no brown pigments)
- Can’t excrete bile acids - Fatty Stool
Major structures in a hepatocyte
Smooth ER - produces cholesterol
Rough ER - makes proteins and albumin
Peroxisomes - metabolize toxins in liver
What do kupffer cells do?
- Phagocytize Substances - “liver macrophages”
- Clear old or malformed erythrocytes
- Phagocytize bacteria - host defence
* can take over function of spleen*
Where do reticular fibers in the liver come from?
Stellate or Ito Cells
Where do kupffer cells originate?
Bone marrow
What type of cells make up the gallbladder?
Simple columnar epithelium (absorption)
What is the gallbladder lined with SCE?
Designed to absorb water and concentrate bile
