Chapter 2 Flashcards
The structure of the liver can be broken into which 3 categories
- hepatic vascular system
- biliary tree
- hepatic lobules
Why is the liver considered a vascular organ?
it has a dual blood supply, and at any given time contains 13% of the bodies blood
Describe the dual blood supply of the liver
Arerial blood supplied by hepatic artery and portal vien brings the liver al the blood that was previously passed through the small intestine and spleen.
What are sinusoids in the liver?
vascular channels lined with highly fenestrated endothelial cells and surrounded by hepatocytes.
what provides a major portion of the body lymps?
plasma that is filtered into the space between the endothelium and hepatocytes
describe the flow of blood int the liver
hepatic portal vein + hepatic artery»_space; sinusoids —^plasma—>central vein of each lobule—-> hepatic veins > (leaves liver)—> inferior vena cava.
What is the biliary system?
a series of channels and ducts that transport bile from the liver into the small intestine.
What cells produce and secrete the bile?
hepatocytes
What happens to bile once it reaches the gallbladder?
its concentrated and stored until it is needed for digestive sxs. it re-enters the common bile duct to form ampulla of vater.
What controls the ampullary opening into the duodenum?
muscle sphincter of Oddi.
What is the hepatic lobule consisted of?
hexagonal arrangement of plates of hepatocytes radiating outwards from a central vein. It encompasses the liver tissue that is served by a single branch of the central vein.
What are portal triads?
regions of connective tissue that include branches of the bile duct, portal vein and hepatic artery.
How many hepatic lobules are in a normal liver?
100K
What is the primary purpose of the liver?
to maintain homeostasis by
- detoxification
- metabolism
- synthesis of lipoproteins and cholesterol
- synthesis of plasma proteins
- synthesis of immune factors
- digestive function
- excretion of bilirubin
- storage
Define liver metabolism
hepatic cells assimilate carbs, fats, and proteins
they convert glucose to glycogen
what Glucogenesis?
production of glucose from sources other than carbs- can be carried out by the liver.
Name the plasma proteins produced by the liver
- albumin
- fibrinogen
- certain globulins (transport proteins)
What do the phagocytes in the liver produce in response to the inflammatory process, tissue repair and immune cell activities?
they produce acute-phase protein in response to microbes
What is the purpose of bile? what does it do?
digests and aids in the absorption of fats. The liver adds a bicarbonate-rich solution of inorganic ions, which helps neutralize acid in the duodenum
What is bilirubin?
results from the breakdown of the hemoglobin in the RBC and is excreted into the bile by hepatocytes.
what happens when bilirubin cannot be removed from the blood quickly enough?
Jaundice
What vitamins and proteins are stored in the liver?
- glucose in form of glycogen
- fats
- iron
- copper
- vit K, A, D, B12
What are some primary issues that are associated with the use of FLT’s for liver pathology screening?
- non-specific to Liver function
- LFTs have low sensitivity and specificity
- results can be affected by several factors
- structural or functional damage can evade detection using BW
LFTs are tested to evaluate the specific aspects of the liver. They can be categorized based on their ability to what (5)
- detect injury to hepatocytes
- determine hepatic biosynthetic capacity
- measure excretory function
- detect chronic inflammation of the liver, and hep
- serve as tumour markers.
Name the enzymes that are sensitivity indicators of hepatic injury
Serum aminotransferases.
ATL, AST
ALT is more specific since it is mainly found in liver, where AST i found in many tissues
Why is LDH not typically concerning in the u/w process?
it adds little evaluation of suspected hepatic dysfunction.
When goes elevation of GGT occur?
with minor subclinical hepatocellular damage, in association in ALT. CAD renal failure MI pancreatic disease DM alcohol/medications
What are GGT enzymes?
they are involved in the transfer of amino acids across cellular membranes.
What is bilirubin?
the main bile pigment that is formed from the breakdown of hemoglobin in red blood cells.
Serum Bilirubin levels reflect the livers ability to do what?
take up, process, and secrete bilirubin into the bile.
What is urobilinogens?
this is the chemical compound that emmerges when the bilirubin is acted on by bacteria in the small intesting entrance.
What gives feces it dark color? What can result from the absence of bilirubin in the intestine?
uribilinogen
clay-colored stools
Bilirubin is chemically different after it goes through the conjugation process in the liver, how do lab test will differentiate between them?
The unconjugated (indirect) and conjugated (direct) bilitybin reflects how it reacts to certain dyes added to the blood specimen.
Unconjugated hyperbilirubinemia is caused by?
- increase production of bilirubin- hemolytic anemia
2. decreased conjugation- familial hyperbilirubinemia.
Conjugated hyperbilirubinemia is caused by?
- decreased secretion of bilirubin by the liver- cirrhosis, hep,
- cholestasis- found in biliary obstruction, cholesdoscholithiasis, stricture, neoplast,
In the liver, what causes increased AP levels?
rise of bile acids, early marker of cholestasis- which results in increased synthesis and secretion of alk Phos
If the AP is elevated d/t hepatic pathology, Will GGT and/or bilirubin also be elevated?
yes
What are the most common causes of AP elevations?
- liver- bilary obstruction, cholestatis
- bone diease-
- malignant tumors
- renal disease
- primary hyperthyroidism
- polycythemia vera
- pregnancy
Where is albumin synthesized?
liver,
What causes Changes in albumin levels?
progressive hepatocellular injury, hepatic synthetic capacity.
heavy alcohol intake and chornic inflammation inhibit albumin synthesis.
What is Alpha-fetoprotein (AFP)
a glycoprotein synthesized in the yolk sac, liver, and GI of the futur. It is a major protein in fetaol serum.
As fetal liver matures it AFP levels decline.
Do normal livers in non-pregnant adults still produce small levels of AFP?
no
Tumor markers can be used for what 4 purposes?
- cancer screening
- making a dx of caner
- determining prognosis
- monitoring effectiveness of cancer treatments.
AFP is a tumor marker for what?
- hepatocellular carcinoma. AFP caused by abN cell proliferation in the liver.
- heptoblastoma and nonseminomatous germ cell tumors-
- cirrhosis and viral hep
What does prothrombin time (PT)measure?
the rate of conversion of prothrombin to thrombin after activation of the extrinsic coagulation pathway.
prolonged= coagulation deficiency/ acute liver disease
Which coagulation factors are synthesized by the liver?
factor 1, 2, 5, 7, 9, 10
What are some non-hepatic causes of prolonged PT times?
Vit K deficiency, coagulopathies, inherited deficiency of a coagulation factor, or medications that antagonize the prothrombin complex (warfarin)
What is Carbohydrate-deficient transferrin (CDT)?
a blood test use to help detect heavy alcohol consumption.
What is transferrin, and what happens to it when you ingest ++ ETOH?
Plasma transport protein for iron.
ETOH causes the make-up of the protein.
What is Hemoglobin-associated acetaldehyde (HAA) assay
A specific confirmation test that distinguishes alcohol-related from non-alchohol-related LFT elevations. ITs a metabolite of Ethanol.
What can be detected through an abdo x-ray (in terms of liver
on occasion, calcificatoins d/t gallstones, cytst, or scarring.
tumors, or vascular lesions
What can be detected through an abdo ultrasound?
first choice study- many hepatobiliary disorders: focal lesions, biliary dilation, stones, and facilitate biopsies or solid hep masses..
in expensive
non invasive,
portable
What can be detected through an abdo CT?
becoming preferred technique for hepatobiliary system- not for GB
-detects masses, and differentiates types, cavernous hemangiomas, and neoplastic vascular invasion. Cirrhosis, and portal HTN, and changes in liver.
What can be detected using an MRI?
characterizing and staging liver leisons seen on other imaging tests.
What is a (Transient Elastography) fibroscan and why is it used?
non invasive procedure that utilizes an ultrasound probe to measure shear wave velocity in order to determine the severity of hepatic fibrosis. Less expensive then biopsy.
- less reliable in people with low grade fibrosis and with acute liver inflammation
What id the purpose of a liver biopsy
confirm dx of specific liver disease.
provides information about structural integrity of the liver, type and degree of injury.
What are the methods for obtaining liver tissue
percutanrous ** transjugular laproscopic ultrasound CT-guided fine needle aspiration
List the informaiton of the liver the biopsy will provide.
- evaluation of abN dx findings and hepatomegaly
- confirm dx and prognosis
- confirm suspected hep neoplasm
- dx cholestatic liver disease
- evaluate infiltration or granulomatous disease
- evaluate and stage chornic hep
- identify and staging of alc. liver disease
- evaluate effectiveness of tx of liver disorders.
What are some risks associated with completing a liver biopsy. What are the limitations
pain, hemorrage, biliary peritonitits,
bacteremia
sampling error, d/t adequacy or location
What is Fatty liver?
what are the classifications?
What is the severity?
when more than 5% of the liver mass is made of fat, usually trigs.
Classified as alcoholic or non-alcoholic
mild stenosis(fatty liver) to inflammation (setathohepatitis) to fibrosis or cirrhosis.
What is NASH?
Non alcoholic steatohepatitis, and can be associated with progressive fibrosis, cirrhosis, and liver failure.
Hepatic stenosis can be caused by what detects in the movement of fatty acids through the liver.
- ^ peripheral mobilization of fatty acids into the liver
- ^ hepatic synthesis of fatty acids
- impaired hepatic catabolism of fatty acids
- impaired synthesis and excretion of VLDL from the liver
- necroinflammatory changes
How are the most advanced stages of NAFLD (nonalcoholic fatty liver disease) marked?
disposition of collagen in the liver, results in -> fibrosis and eventually cirrhosis.
What are the causes of NAFLD?
poorly controlled diabetes insulin resistance metabolic syndrome hyperlipidemia obesity acute starvation post-bariatric surgery medications
How is NAFLD detected?
most people are Asxs
-usually indicated by mildy elevated ALT and/or AST.
Ferritin levels are also increased
- U/s, CT/ and MRI are reliable to detect moderate to severe Fatty changes in liver.
Which immaging test is able to distinguish between simple steanosis and NASH or indicating the stage of fribrosis?
none
Liver biopsy- dx the presence and extend of NAFLD.
If a disease progresses from simple steatosis to NASH, what would you find on the liver boipsy?
- stetosis- fat droplets within hepatocytes
- inflammation
- mallory bodies
- glycogen nuclei
- fibrosis- chicken wire pattern
- cirrhosis
NAFLD is not curable, but what can help prevent the progression?
weight loss, diet modifications to reduce carbs and fats, and tighter control of hyperlipidemia and diabetes resistance.
The pathology of alcoholic liver injury comprises which 3 major components?
- fatty liver,
- alcoholic hepatitis
- cirrhosis
What are 7 risk factors that affect alcoholic liver disease>
- quantity of ETOH
- female gender
- hep C (HCV)
- genetic variability in alcohol-metabolizing enzymes
- malnutrition
- co-exposure to drug toxins
- immunologic dysfunction.
How does the Wold Health Organizations define cirrhosis?
- a diffuse process characterized by fibrosis and the conversion of normal liver architecture into structurally abN nodules that lack normal lobular organizations.
> > an irreversible` chronic injury of the hepatic parenchyma and includes extensive fibrosis in association with the formation of regenerative nodules.
What are the 5 criterias used to determnine a dx of cirrhosis?
- pronounced, insufficiently repaired necroses of the parenchyma
- diffuse connective tissue proliferation
- varying degrees of nodular parenchymal regeneration
- loss and transformation of the lobular structure within the liver as a whole
- impaired intrahepatic and intra-acinar vascular supply.
Why is cirrhosis classified based on ethology of the disease?
- morphologic classification is more difficult to determine d/t the overlap of findings amoung different etiologies, and
- tx and prognosis are based on etiology.
What are the major causes of cirrhosis?
alchohol, chronic infection cholestasis autoimmune hep chemical agents venous congestion hemochromatosis NASH
What does cirrhosis cause? sxs of the impairement
jaundice portal HTN esophageal varices ascites spintaneous bacterial perionitits hepatorenal syndrome hepatic encephalopathy coagulopathy.
What is Jaundice and the 3 classes of cause for it?
Its the excess levels of bilirubin
- pre-hepatic or hemolytic jaundice- d/t increased breakdown of RBC
- hepatic jaundice
- extrahepatice Jaundice( obstructive)