Liver, Bile, peritoneum, pancreas and imaging Flashcards
What is the liver
Is a vital organ with a complex structure and diverse functions that plays a key role in metabolism, detoxification, and nutrient storage
Where is the liver in the abdomen
Located in the dome of the diaphragm within the abdominal cavity
4 main lobes of liver
left, quadrate, right, caudate
Parts of caudate lobe (in most species )
2 parts- caudate and papillary processes
How are the liver lobes divided (dog,cat)
split into medial and lateral parts
What do the liver lobes allow
movement of organ due to diaphragm
Name some functions of the liver
removal of bacteria
production of clotting factors
breakdown of RBC (degradation of haem)
carbohydrate, lipid, amino acid metabolism
synthesis of plasm proteins
storage of glycogen, iron, copper and vitamins
detoxification of body wastes, xenobiotics and drugs
synthesis of cholesterol and bile acids
percentage of blood entering liver from hepatic portal vein
75%
percentage of blood entering liver from hepatic artery
25%
Blood flow for sinusoids
venous and arterial blood mix as they flow into sinusoids
blood flow for central veins
blood from sinusoids empty into central veins
blood flow for hepatic veins
central veins coalesce into hepatic veins
blood flow for caudal vena cava
hepatic veins empty into caudal vena cava
What is the portal vein
vital blood vessel that carries nutrient-rich, deoxygenated blood from GI tract to the liver for processing, It allows the liver to metabolize nutrients, detoxify harmful substances, and produce essential proteins
What are portosystemic anastomoses
connections between the veins of the portal venous system and systemic venous system
Use of portosystemic anastomoses
alternative pathways for blood to bypass the liver when normal portal circulation is obstructed, such as portal hypertension
What is bile
yellow-green fluid essential for digestion and absorption of fats, as well as the excretion of waste products like bilirubin and cholesterol
What is the enterohepatic circulation
process of bile production, storage , release and recycling involving the liver, gall bladder and small intestine in a continuous cycle
Describe the rough hierarchy of biliary system
Hepatocytes, canaliculi, ductules, ducts, hepatic bile ducts, cystic duct and gallbladder, common bile duct
Cholesterol breakdown for synthesis of bile acids products
cholic acid and chenodeoxycholic acid
Cholic acid bio synthesis of primary bile acid product
glycocholic acid
Chenodeoxycholic acid bio synthesis of primary bile acid product
Taurochenodeoxycholic acid
Cholic acid bio synthesis secondary bile acid product
Deoxycholic acid
Chenodeoxycholic acid bio synthesis of secondary bile acid product
Lithocholic acid
What is Intrahepatic circulation
network of blood flow within the liver
what is the role of intrahepatic circulation
processing nutrients, detoxifying harmful substances, and managing the flow of bile
What is the peritoneum
Large and continuous membrane that lines the abdominal cavity and covers most of the abdominal organs
What is the parietal peritoneum
outer layer that lines the walls of the abdominal cavity
What is the visceral peritoneum
inner layer that covers the surfaces of abdominal organs, such as the stomach, liver, intestines, and others.
What is the omentum
double- layered fold of peritoneum that connects the stomach to other organs such as the intestines and the spleen
what is the greater omentum
larger, apron like structure that hangs down from the greater curvature of the stomach and drapes over the intestines
what is the lesser omentum
smaller fold that connects the lesser curvature of the stomach and the first part of the duodenum to the liver
what is omental milking
physiological process involving the omentum, a fatty layer of tissue in the abdomen that plays a key role in the immune response by encapsulating the infection so inflammatory cells can be carried to infection.
facilitating the localized immune response
Structure of the pancreas
Head body and tail and lies close to the duodenum
types of tissue of the pancreas and percentage make-up
exocrine tissue 98%
endocrine tissue 2%
2 major functions of pancreas
digestion (exocrine)
regulation of metabolism (endocrine)
percentage mass of pancrease of the islets of langerhans
1-2%
major types of cell of islets of langerhans
B(65%), a(-25%), δ(-10%)
Hormones of pancreas endocrine
insulin B cells
glucagon a cells
somatostatin δ cells
What does somatostatin do
paracrine effect to inhibit both insulin & glucagon secretion
where do pancreas endocrine hormones get secreted to
blood stream and passes to liver via hepatic portal vein prior to circulating to other tissues
Haem conversion to bile pigments stages
Haem-> biliverdin
Biliverdin-bilirubin
bilirubin-> transported to liver in blood bound to albumin
bilirubin-> conjugated with glucoronic acid
What do kupffer cells do
remove bacteria, debris, and damaged red blood cells from the bloodstream
What forms the portal vein
superior mesenteric vein
splenic vein
Where does the superior mesenteric vein drain blood from
small intestine, cecum, ascending colon and transverse colon
Where does the splenic vein drain blood from
spleen and receives tributaries like the inferior mesenteric vein( rectum sigmoid colon and descending colon)
What do hepatocytes do
extract and metabolize nutrients, detoxify substances and synthesize bile
Location of oesophageal anastomoeses
portal system-left gastric vein
systemic-oesophogeal vein
Location of rectal anastomoses
portal system- superior rectal vein
systemic- inferior rectal veins
Location of paraumbilical anastomoses
portal system- paraumbilical vein
systemic- superfical epigastric veins
Location of retroperitoneal anastomoses
portal system- colic veins
systemic- retroperitoneal veins
Location of hepatic anastomoses
portal system- liver capsule
systemic- diaphragm and thoracic wall veins
Structure of liver
lobes( left, right, quadrate, caudate)
blood supply- hepatic artery and portal vein
hepatocytes are main functional cell
function of liver
detoxification, metabolism, protein sysnthesis
bile production
storage of vitamins and glycogen
What happens in dog, cat and pig liver
left and right lobes split into medial and lateral parts
Parts of caudate love
caudate and papillary processes
What do lobes allow
movement of organ due to diaphragm
Dog and cat liver lobes structure? and organisation of liver cells/tissue
structure and organized lovular design with defined portal triads, sinusoids and connective tissue
Rodents liver lobes structure? and organisation of liver cells/tissue
Liver lobules are smaller and less clearly defined than dogs, central vein and portal triads have limited connective tissue delineation
Birds, reptiles and fish liver lobes structure? and organisation of liver cells/tissue
Poorly organized or absent lobular structure and hepatocytes arranged in less distinct patterns
What is portal vein
collects blood from GI tract, spleen and pancreas and merged with hepatic vein in liver
What are porto-systemic anastomoses
alternative pathways when portal circulation is obstrucutred
Sites- oesophagus, rectum and umbilicus
Where is bile production and components
originates in hepatocytes and contains: bile salts, bilirubin, cholesterol and water
What is cycling (bile)
stored in gallbladder between meals, released via common bile duct into duodenum, enterohepatic circulation
What is enterohepatic circulation
Bile salts reabsorbed in the ileum
What is peritoneum
serous membrane lining abdominal cavity
Function of peritoneum
friction reduction, protection and support for organs
What is omentum
double layered peritoneal fold
Function of omentum
fat storage, immune response and infection isolation
Pancreas Structure
Divided into exocrine(acini) and endocrine (islets of Langerhans)
Function of pancreas
Exocrine- digestive enzymes (amylase, lipase) and bicarbonate
Endocrine- secretion of insuline, glucagon and somatostatin
What hormone is responsible for releasing Bile
CCK
