Brainscape's Knowledge GenomeTM

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


See full index

PHYSIOLOGY III > L35: Hepatic physiology > Flashcards

L35: Hepatic physiology Flashcards

1
Q

what organ has the greatest regenerative capacity

A

liver; it is able to regenerate

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

what are the 2 blood sources of the liver

A
  • hepatic artery from the aorta (provides O2)
  • hepatic portal vein from the GI tract (provides nutrients)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

where does the hepatic portal vein collect blood from

A

stomach, SI and part of LI
takes nutrients and delivers it to the liver

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

most of the liver blood is ____ blood

A

venous
increases after a meal

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

through what vein does blood leave the liver

A

heaptic vein

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

what are the functional units of the liver

A

lobules = hexagonal tissue surrounding a central vein

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

what is the role of Kupffer cells

A

destroy old RBCs and bacteria
get exposed to large volumes of blood

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

Vitamin A is stored as ____ in ?

A

retinol
hepatocytes or stellate cells

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

what is the space of disse

A

space b/w hepatocytes and sinusoids
fills w/ collagen = fibrosis

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

what is the portal triad

A

the 3 vessels in a lobule that drain into a central vein
- bile duct
- hepatic artery
- portal vein

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

blood enters the sinusoids from the _____ vein and the ____ artery

A

portal vein and hepatic artery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what are the different zones in the lobule

A

periportal hepatocytes (zone I)
centrilobular (pericentral, zone II)
hepatocytes (zone III)

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

what is responsible for the variability in activity of each zone of the lobule

A

heterogeneity of O2 supply

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

what zone of the lobule is highest in O2

A

zone I
* has many mitochondria
* oxidative metabolism
* bile acid secretion
* glycogen and other nutrient storage

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

what lobule zone is responsible for bile acid secretion

A

zone I

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

what lobule zone is concerned w/ oxidative metabolism (FA oxidation, gluconeogenesis, urea genesis)

A

zone I

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

what zone is the transition zone

A

zone II

18
Q

What lobule zone is lowest in O2 and therefore anaerobic metabolism occurs here

A

zone II

19
Q

in what zone of the lobule does biotransformation of drugs/chemicals/toxins occur

A

zone III

20
Q

what zone is most sensitive to damage caused by ischemia

A

zone III - least O2 supply
most susceptible to centrilobular necrosis, hypoxia, congestion

21
Q

what is centrilobular necrosis and what zone does it usually occur

A

necrosis around the central vein
zone III

22
Q

what are the 2 capillary beds blood runs through before it returns to the heart

A
  • mesenteric
  • portal
23
Q

what drives blood through the portal capillary bed

A
  • pressure in portal vein being higher than in the hepatic sinusoids (precapillary resistance in portal inflow is low)
  • central vein of liver is large so resistance is low
  • venous outflow of the liver goes into thoracic vena cava
24
Q

what is the consequence of right sided heart failure on the liver?

A

it increases vena cava pressure which leads to reduced blood flow from the intestine
excess interstitial fluid leaks into edematous tossie and accumulates in the peritoneal cavity (ascites)

25
Q

what can cause necrosis of zone 1 (periportal)

A
  • phosphorous poisoning (rat poison, fertilizer, fireworks)
  • eclampsia (sudden pregnancy/postpartum seizures)
26
Q

what can cause necrosis of zone 3 (centrilobular zone)

A
  • ischemic injury
  • toxic effects
  • carbon tetrachloride exposure
  • chloroform ingestion
27
Q

what liver enzymes are most likely elevated when there is an increase in cell membrane permeability or death

A
  • alanine transaminase (ALT)
  • asparate transaminase (AST)
  • alkaline phosphatase (ALP)
  • gamma glutamyl transpeptidase (GGT)
28
Q

elevated liver enzymes may indicate?

A

inflammed or damaged liver cells b/c they leak higher than normal amounts of enzymes into the bloodstream which can result in elevated liver enzymes in a blood test

29
Q

why does a decreased uptake and conversion of ammonia into urea cause high ammonia concentrations

A

high ammonia concentration in urine are followed by low urea nitrogen concentration and PU/PD
b/c urine concentrating ability depends on medullary interstitial tonicity which is generated by urea and NaCl

30
Q

what is the function of bile

A
  • excretory route for solutes that aren’t excreted by the kidney
  • bile salts and acids are needed for lipid digestion and absorption
31
Q

what is the composition of bile

A
  • bile salts (50%)
  • phospholipids (40%)
  • bilirubin, electrolytes, water
32
Q

bile is continuously secreted by ____ into _____

A

hepatocytes into canaliculi

33
Q

where are bile caniculi located

A

b/w adjacent hepatocytes, they drain into bile ducts at the periphery of lobules

34
Q

what are the 2 primary bile acids

A
  • cholic acid
  • chenodeoxycholic acid
35
Q

what does the liver conjugate bile acids w/

A

Taurine and glycine

36
Q

what are the 2 secondary bile acids and how are they formed

A

deoxycholic and lithocholic acid
primary bile acids that get dehydroxylated by bacteria into secondary bile acids

37
Q

bile salts are derivates of ?

A

cholesterol

38
Q

what happens to bile salts after they are used in fat digestion and absorption

A

they get reabsorbed into the blood through an active transport mechanism in the distal ileum and by passive absorption throughout the intestine

39
Q

what are the sites at which bile salts get reabsorbed

A
  • distal ileum (via active transport)
  • throughout the intestines (passive abs)
40
Q

after being reabsorbed how do bile salts get back to the liver

A

hepatic portal system
= enterophepatic circulation

41
Q

is bilirubin involved in digestion

A

no but excreted in bile

PHYSIOLOGY III (31 decks)

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