- Fatty acid metabolism by provide surface-active detergent molecules that facilitate excretion of cholesterol and solubilization of the lipids for intestinal absorption. - Excretion of waste products. - Kill off bad microbes. - Blood sugar metabolism

12) Liver function Flashcards by Samantha Boyer

what makes the liver unique?

only organ in mammals that can regenerate

How well did you know this?

Not at all

Perfectly

divides liver’s lobes

falciform ligament

How well did you know this?

Not at all

Perfectly

liver receives —% of blood per minute

How well did you know this?

Not at all

Perfectly

explain dual blood supply of liver

Portal vein: Carries blood from GI tract (nutrient rich) and spleen

Hepatic artery: a branch of celiac axis (well-oxygenated)

How well did you know this?

Not at all

Perfectly

liver lobule

Basic microscopic unit
contains four to six portal triads

How well did you know this?

Not at all

Perfectly

portal triad has branches of…

Portal vein
Hepatic artery
Bile duct

How well did you know this?

Not at all

Perfectly

acinus

Functional anatomical unit of the liver

Diamond-shaped mass of liver parenchyma

How well did you know this?

Not at all

Perfectly

kupffer cells

phagocytes that engulf bacteria, old red blood cells (RBCs), toxins, and cellular debris from the blood flowing through the sinusoids

How well did you know this?

Not at all

Perfectly

The ———— and ———– flow in opposite directions.

bile in the bile canaliculi
blood in the sinusoids

How well did you know this?

Not at all

Perfectly

space of disse

Space between the endothelial cells and hepatocytes where nutrient uptake occurs

How well did you know this?

Not at all

Perfectly

5 major categories of liver function

Metabolism
Excretion
Detoxification
Storage
Immunologic

How well did you know this?

Not at all

Perfectly

liver’s metabolism functions

Most of plasma proteins, except gamma globulins, vWF, and hemoglobin
Produces, stores, and breaks down glycogen
Lipid and lipoprotein synthesis
Synthesis of Urea

How well did you know this?

Not at all

Perfectly

liver’s excretion functions

Bile acids
Cholesterol
Bilirubin

How well did you know this?

Not at all

Perfectly

bile functions

Fatty acid metabolism by provide surface-active detergent molecules that facilitate excretion of cholesterol and solubilization of the lipids for intestinal absorption.
Excretion of waste products.
Kill off bad microbes.
Blood sugar metabolism

How well did you know this?

Not at all

Perfectly

liver’s detox functions

Bilirubin conjugated to direct bilirubin
Drugs
Alcohol dehydrogenase

How well did you know this?

Not at all

Perfectly

liver’s storage functions

Glycogen
Iron
Copper
Vit A, D, E, K

How well did you know this?

Not at all

Perfectly

liver’s immunologic functions

Phagocytosis of bacteria and other substances by Kupffer cells
Secretion of I g A

How well did you know this?

Not at all

Perfectly

Approximately 200 to 400 mg of bilirubin produced daily, 80% of which is produced from…

hemoglobin released from old RBCs.

How well did you know this?

Not at all

Perfectly

Degradation of RBCs occurs in the…

macrophages of the reticuloendothelial system (spleen, liver, and bone marrow).

How well did you know this?

Not at all

Perfectly

what happens to hemoglobin’s porphyrin ring?

Converted to biliverdin (green bilirubin) by the action of heme oxidase
Biliverdin is reduced to unconjugated bilirubin by biliverdin reductase in the macrophages
Unconjugated bilirubin is transported to the liver by plasma albumin

How well did you know this?

Not at all

Perfectly

unconjugated bilirubin has an affinity for…

nervous tissue

kernicterus

How well did you know this?

Not at all

Perfectly

Unconjugated bilirubin reaches liver
albumin is removed in the sinusoidal space
enters the hepatocyte by binding to ——- or passive diffusion.

ligandin

How well did you know this?

Not at all

Perfectly

Unconjugated bilirubin is conjugated to glucuronic acid by …

UDP-glucuronyl transferase

How well did you know this?

Not at all

Perfectly

3 types of conjugated bilirubin found in plasma

Bilirubin monoglucuronide
Bilirubin diglucuronide
Delta bilirubin

unconjugated is found in serum

How well did you know this?

Not at all

Perfectly

conjugated bilirubin is bound to ------ acid

glucaronic

Seen only in cases of significant hepatic obstruction

delta bilirubin

pathway of conjugated bilirubin

Bile canaliculi → larger bile ducts → hepatic ducts → gallbladder → duodenum

Conjugated bilirubin is metabolized into ----------, ----------, and ---------- by bacteria enzyme.

urobilinogen stercobilinogen mesobilinogen

------------- is accountable for more symptoms of jaundice than ------------ because it is more easily absorbed into the tissues

conjugated unconjugated

types of prehepatic jaundice

- increased production of bilirubin (hemolysis, dyserythropoiesis) - decreased delivery to hepatocytes

most common cause of unconjugated hyperbilirubinemia

neonatal jaundice

examples of posthepatic jaundice

- Common bile duct stones, gallbladder stones (most common) - Cancer of the bile ducts, pancreas, or ampulla of Vater - Bile duct stricture or stenosis

↑ total bilirubin N conj. bilirubin ↑ unconj. bilirubin ↑ urine urobilinogen N or ↑ fecal urobilinogen N urine bilirubin

prehepatic jaundice

↑ total bilirubin ↑ conj. bilirubin ↑ unconj. bilirubin ↑ or N urine urobilinogen N or ↑ fecal urobilinogen ↑ urine bilirubin

hepatic jaundice

↑ total bilirubin ↑ conj. bilirubin ↑ unconj. bilirubin ↓ urine urobilinogen ↓↓ fecal urobilinogen ↑ urine bilirubin

posthepatic jaundice

Benign condition manifested by mild unconjugated hyperbilirubinemia

gilbert's syndrome

Rare disorder caused by complete absence of UDP-glucuronyl transferase

Crigler-Najjar Syndrome (CNS)

Most patients die of severe brain damage caused by kernicterus within the first year of life.

type 1 CNS

Milder form, partial deficiency of enzyme, 10% of enzyme activity.

type 2 CNS

Defect in canalicular excretion of the conjugated bilirubin into the bile.

Dubin-Johnson Syndrome (DJ)

Dark brown pigment, **lipofuscin**, in hepatocytes and Kupffer cells

Dubin-Johnson Syndrome (DJ)

Defect in hepatic uptake and storage of bilirubin

rotor syndrome

Rapidly progressive encephalopathy with hepatic dysfunction Often begins several days after apparent recovery from a viral illness, especially varicella or influenza A or B Salicylate use identified as a risk factor in kids with varicella or influenza A or B

Reye's syndrome

Vomiting and confusion, rapidly evolving to seizures and coma.

Reye's syndrome

causes of hepatitis

Infections (viral hepatitis) Toxic (alcohol-related disease) Genetic (hemochromatosis) Immune (autoimmune hepatitis and primary biliary cirrhosis) Neoplastic (hepatocellular carcinoma)

picornavirus

HAV

hepadnavirus

HBV | also Dane particle

Persistent HbsAg without clinical hepatitis

chronic carrier

Always present once infected with HBV

HBcAb

Indicates recovery from HBV infection or immunity status

HBsAb

core window

Brief interval between disappearance of HBsAg and appearance of HBsAb during HBV infection

flaviviridae

HCV

75% acutely infected individuals fail to clear the virus and develop a chronic infection

HCV

coinfection vs superinfection

**Coinfection**: Infections with two virus at the same time; **Superinfection**: HDV infection occurs in the presence of persistent HBV infection

Infection when HBsAb is present but observe clinical deterioration of the patient

suspect HDV

80%-90% develop chronic hepatitis, leading to cirrhosis or hepatic cancer

HDV coinfection

herpesvirus

HEV

Devastating to pregnant women (20% mortality rate for both mom & baby)

HEV

hepatitis with no vaccine

HCV HEV

most common causes of chronic hepatitis

hepatitis B hepatitis C autoimmune disease Wilson disease α1-antitrypsin deficiency

suspect ALD in these pts

>15 drinks per week for men and >10 drinks per week for women over at least a two-year period

Fat accumulation in the hepatocytes.

steatosis

Occur within two weeks of regular alcohol ingestion and resolves rapidly with abstinence

alcoholic steatosis

Fatty accumulation in the hepatocytes and inflammation

alcoholic steatohepatitis

Follows 6 months to a year of moderate alcohol consumption

alcoholic steatohepatits

Symptoms caused by the loss of functioning hepatocytes, increased resistance to hepatic blood flow or portal hypertension, ascites, and hepatic encephalopathy

cirrhosis

leading cause of both chronic hepatitis and cirrhosis

HCV

cirrhosis complications

- Portal hypertension - Varices formed in the stomach and esophagus - Edema and ascites - Bruising - Itching - Hepatic encephalopathy

Child-Turcotte-Pugh cirrhosis stages

Class A: score <7 points Class B: 7-9 points Class C: 10-15 points

3 blood tests used to get Model for End-Stage Liver Disease (MELD) stage

Bilirubin Prothrombin time Creatinine

3 inherited liver diseases that present as chronic hepatitis

Hereditary hemochromatosis (HH) Wilson disease α1-antitrypsin deficiency (AAT)

Mutations in the HH gene (HFE), increased intestinal iron absorption can lead to total-body iron overload.

hereditary hemochromatosis

Associated with lung (emphysema) and liver disease

AAT deficiency

Impairment in the excretion of bile

cholestasis

T-lymphocyte-mediated attack on small interlobular bile ducts.

Primary biliary cirrhosis (PBC)

Chronic inflammatory disease of unknown origin Inflammation, fibrosis and obliteration of the intrahepatic and extrahepatic bile ducts

Primary sclerosing cholangitis (PSC)

associated with IBD

Primary sclerosing cholangitis (PSC)

The presence of hepatic steatosis in the absence of excessive alcohol consumption.

Nonalcoholic fatty liver disease (NAFLD)

Fat accumulation and inflammation and/or fibrosis ALT level is ≥ AST (De Ritis ratio <1)

Nonalcoholic steatohepatitis (NASH)

Jendrassik-Grof Test

bilirubin method

**Jendrassik-Grof Test** Bilirubin pigments react with a ----- reagent ---------- is added (stops reaction by destroying excess sulfanilic acid) ----------- promotes the displacement of bilirubin from albumin and increases the reaction rate. ----------- buffers the solution. Results in formation of ----------- Azobilirubin

diazo ascorbic acid caffeine sodium benzoate blue-green

Converts purple azobilirubin to blue azobilirubin.

Alkaline tartrate

2 possible results of PT test with injected vitamin K

PT corrects: Malabsorption of vitamin K in **cholestasis** PT doesn’t correct: **Hepatocellular** disease

ammonia elevated in...

advanced liver disease renal failure

ammonia sample

arterial blood preferred avoid tourniquettes, fist clenching if venous heparinized on ice, centrifuged, separated w/i 15 mins

Berthelot reaction

ammonia method

glutamate dehydrogenase

ammonia method