Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

GI Final > Hepatobiliary Function > Flashcards

Hepatobiliary Function Flashcards

1
Q

Main functions of the liver

A

Bile production and secretion

Metabolism of carbs, proteins, and lipids

Bilirubin production and excretion

Detoxification of substances

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Chronic liver disease in which normal liver cells are damaged and replaced by scar tissue (fibrosis)

A

Cirrhosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Most common cause of cirrhosis

A

Excessive alcohol intake

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How does excess alcohol intake lead to cirrhosis?

A

Initial accumulation of fat within hepatocytes leads to steatohepatitis (fatty liver + inflammation) which leads to liver scarring and cirrhosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Chronic disease that causes bile ducts in liver to become inflamed, damaged, and are eventually lost

A

Primary biliary cirrhosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Most common cause of portal HTN

A

Cirrhosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Portal HTN develops when there is increased _____ to portal blood flow, which most often occurs in the liver

A

Resistance

[this increase in resistance is because of loss of connections in parallel]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Complications of portal HTN in the setting of cirrhosis

A

Hepatic encephalopathy
Esophageal varices
Splenomegaly
Ascites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What changes in the starling forces cause ascites in the setting of cirrhosis?

A

Cirrhotic liver produces less albumin, thus reducing oncotic pressure

Increased portal pressure leads to increased hydrostatic pressure

Fluid begins leaving mesenteric capillaries into interstitial spaces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Bile is produced and secreted by the ___

A

Liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Composition of bile

A 
Bile salts (50%)
Bile pigments like bilirubin (2%)
Cholesterol (4%)
Phospholipids, such as lecithin (40%)
Ions
Water
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Primary function of bile

A

Solubilizes lipids that are naturally insoluble by forming micelles; vehicle for elimination of substances from the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Formation of bile salts begins with primary bile acids, then secondary bile acids, then bile salts.

There are relative amounts of bile acids, which ones are most common?

A

Cholic acid > chenodeoxycholic acid > deoxycholic acid > lithocholic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Where are primary bile acids synthesized?

A

Hepatocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Where are secondary bile acids synthesized

A

Small intestine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Primary bile acids are synthesized in the liver from ________, catalyzed by the ______ enzyme to become cholic or chenodeoxycholic acid

A

Cholesterol; 7-alpha hydroxylase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Where are bile salts conjugated?

A

Liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the primary hormonal mediator of bile secretion? What does it cause?

A

CCK

Causes contraction of gallbladder and relaxation of the sphincter of Oddi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Action of CCK is mediated through extrinsic _____ and intrinsic _____ nerves

_____ may antagonize CCKs actions

A

Vagal; cholinergic

Secretin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What effect do pancreatic polypeptide and somatostatin have on gallbladder contractility?

A

Decrease it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How does the parasympathetic nervous system affect bile secretion?

A

Stimulation via vagus nerve:
Increases bile flow
Induces contraction of gallbladder

[sympathetic system opposes these things]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the role of secretin in bile secretion from the liver?

A

After bile is secreted from the liver, secretin stimulates addition of ions and water, thus diluting the bile

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

After bile is released from the liver, where does it go? What does it do there?

A

Gallbladder, which concentrates the bile

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

CCK stimulates contraction of the gallbladder and relaxation of the sphincter of Oddi. Where does the bile that is released go from there?

A

Enters duodenum, travels through to ileum, and gets reabsorbed via portal circulation for recycling back to the liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

________ bile is secreted by ductule cells in response to the osmotic effects of anion transport

Newly synthesized and returning bile acids are secreted into the _________ as conjugated bili

A

Canalicular

Bile canaliculi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Although most bile transported through the small intestine is recycled, some is excreted in ______. The more that is lost, the _____ gets synthesized

A

Feces; more

[so fecal loss should equal hepatic synthesis of bile]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What transporters in the basolateral membrane of hepatocytes are responsible for bile reuptake/recylcing back into hepatocytes from enterohepatic circulation?

A

NTCP

OATP

28
Q

Increased bile secretion should increase the rate of its return via enterohepatic circulation, this will lead to negative feedback on bile synthesis once enough is produced. Thus, the ______ enzyme is inhibited by bile salts

A

Cholesterol 7-alpha hydroxylase

29
Q

Interruption of enterohepatic circulation can ______ bile synthesis to values >10x normal

A

Increase

30
Q

What is the difference between bile acid-dependent secretion, and bile acid-independent secretion?

A

Acid-dependent = driven by bile acids

Acid-independent = driven by secretin (small portion of bile)

31
Q

Secretin stimulates HCO3 and water secretion from ______ cells, which increases volume, ______ pH, and ______ bile salt concentration

A

Ductile; increases; decreases

32
Q

______ bile is plasma ultrafiltrate

A

Cannalicular

33
Q

Describe bile acid secretion between meals (aka the interdigestion period)

A

Gallbladder fills with bile
Gallbladder is relaxed
Sphincter of Oddi is closed

34
Q

Describe bile acid secretion upon ingestion of food

A

CCK is released from I cells in duodenum
Contraction of gallbladder
Relaxation of sphincter of Oddi

35
Q

Bilirubin is initially produced from the breakdown of RBCs via the ________ system, forming bilirubin-albumin which travels to the ______ where it is conjugated. Some of the conjugated is excreted in the urine, but some is secreted in the _______ which travels to the small intestine and colon. Conjugated bilirubin that takes the latter route is converted to _______, then either _____ or ______ which are excreted in feces and give stools their darker color

A

Reticuloendothelial; liver; bile; urobilinogen; urobilin; stercobilin

36
Q

What enzyme, responsible for the conjugation of bilirubin, is synthesized slowly in newborns, thus explaining the relatively common incidence of neonatal jaundice?

A

UDP-gucuronyl transferase

[forms bilirubin glucuronide which is yellow]

37
Q

What are the steps of bilirubin formation from RBCs via the reticuloendothelial system?

A

RBCs —> hemoglobin released —> broken down to biliverdin —> bilirubin —> leaves via bloodstream as bilirubin-albumin

38
Q

______ = icturus

A

Jaundice

39
Q

Jaundice is a sign of what SPECIFIC medical condition

A

Hyperbilirubinemia

40
Q

What are the 5 known hereditary defects in bilirubin metabolism

A 
Gilbert’s syndrome
Dubin-Johnson syndrome
Rotor syndrome
Crigler-najjar syndrome type 1
Crigler najjar syndrome type 2
41
Q

Is the following condition associated with conjugated or unconjugated bilirubin?

Biliary tree obstruction

A

Conjugated

42
Q

Is the following condition associated with conjugated or unconjugated bilirubin?

Dubin Johnson syndrome

A

Conjugated

43
Q

Is the following condition associated with conjugated or unconjugated bilirubin?

Gilbert’s syndrome

A

Unconjugated

44
Q

Is the following condition associated with conjugated or unconjugated bilirubin?

Rotor syndrome

A

Conjugated

45
Q

Is the following condition associated with conjugated or unconjugated bilirubin?

Crigler najjar syndrome

A

Unconjugated

46
Q

Is the following condition associated with conjugated or unconjugated bilirubin?

Hemolytic anemia

A

Unconjugated

47
Q

Is the following condition associated with conjugated or unconjugated bilirubin?

Heart failure

A

Unconjugated (decreased delivery of bilirubin for conjugation)

48
Q

Why does hemolytic anemia lead to increased unconjugated bilirubin leading to jaundice?

A

With more hemolysis, more bilirubin gets produced which at that point is unconjugated

49
Q

2 main causes of neonatal jaundice

A

Elevated bilirubin production d/t breakdown of fetal erythrocytes

Low activity of UDP glucuronyl transferase

50
Q

What condition is characerized by increased levels of unconjugated bilirubin in the blood due to a mutation in the gene that codes for UDP glucoronyltransferase, is often asymptomatic and episodes of jaundice are typically brought on by physiologic stress?

A

Gilbert’s syndrome

51
Q

What is Crigler Najjar syndrome? What is the difference between the 2 types?

A

Increased levels of unconjugated bilirubin in the blood due to mutation in the gene that codes for glucuronyltransferase

Type 1 = severe
Type 2 = less severe

52
Q

Form of brain damage caused by neural accumulation of unconjugated bilirubin, leading to permanent neurologic sequelae of bilirubin-induced neurologic dysfunction

A

Kernicterus

53
Q

Which type of crigler-najjar syndrome starts earlier in life, is associated with kernicterus, and does not respond to phenobarbitol?

A

Type 1

54
Q

Which type of Crigler Najjar starts later in life, has less than 20% function of UDP glucuronyltransferase, is less likely to develop kernicterus and can be treated with phenobarbitol?

A

Type 2

55
Q

Dubin Johnson syndrome is associated with ________ bilirubin in the serum without elevation of liver enzymes. This condition results from a mutation in _____ which affects the ability of hepatocytes to secrete conjugated bilirubin into bile. Another characteristic sign is _____ pigmentation in the liver

A

Conjugated; MRP2; black

56
Q

Rotor syndrome is associated with both unconjugated and conjugated bilirubin in the blood but the majority is ______, due to mutations in _____ and _______. It is similar to Dubin Johnson, except that ____ cells are not pigmented

A

Conjugated; OATP1B1; OATP1B3; liver

57
Q

What is the primary treatment in neonates with unconjugated hyperbilirubinemia? How does this work?

A

Phototherapy

Process of isomerization that changes trans bili to cis bili

58
Q

4 primary causes of gallstones

A
  1. Too much absorption of water from bile
  2. Too much absorption of bile acids from bile
  3. Too much cholesterol in bile
  4. Inflammation of epithelium
59
Q

Which of the following is the most common?

A. Small gallstones impacted in cystic duct; causing acute cholecystitis
B. Small stones intermittently blocking cystic duct; causing intermittent biliary pain
C. Large gallstones that stay in the gallbladder; usually asymptomatic
D. Small stones impacted in distal bile duct; causing jaundice, biliary type pain, and risk of cholangitis and pancreatitis
E. Cannot be determined

A

C. Large gallstones that stay in the gallbladder; usually asymptomatic

(Followed by B, A, then D]

60
Q

The liver modifies drugs or toxic substances through the “____ _____ metabolism”

A

First pass

61
Q

Liver enzymes can modify both drugs, endogenous, and exogenous toxins to render them water soluble, which allows the excretion of these substances through bile or urine

What are the 2 possible phases of metabolism?

A

Phase 1 = drugs are processed via cytochrome p450 enzymes

Phase 2 = conjugation with glucuronide, sulfate, amino acids, or glutathione for further detox of drug

62
Q

One type of LFT is liver enzymes tests, which are commonly measured in the serum. What are these tests and what might they indicate?

A

Serum aminotransferase (ALT and AST) - when elevated, indicates hepatocyte injury

Alkaline phosphatase - when elevated indicates cholestasis

63
Q

Abnormal serum levels of what compounds might indicate impaired hepatic synthetic function?

A

Bilirubin
Albumin
Prothrombin time

64
Q

Why is albumin used as a liver indicator?

A

Severe impairment in liver function/hepatocyte function reduces albumin levels (i.e., liver failure)

Albumin is exclusively synthesized in the liver and levels will fall with worsening cirrhosis

65
Q

What LFT reflects the degree of hepatic synthetic dysfunction based on its increase as the ability of cirrhotic liver to synthesize clotting factors diminishes?

A

Prothrombin time (PT)

[also known as INR]

GI Final (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions