Liver Physiology

Question 1

functions of the liver

Answer 1

1. metabolism: nutrients, drugs
2. detoxification: bilirubin
3. production: glucose, albumin
4. storage: glycogen, vitamins, copper

Question 2

lobes of the liver

Answer 2

1. right lateral
2. right medial
3. quadrate
4. left medial
5. left lateral
6. caudate

Question 3

where is the gallbladder located

Answer 3

between right medial and quadrate lobes

Question 4

normal appearance of the liver

Answer 4

red, smooth capsule

Question 5

enhanced reticular pattern

Answer 5

distinct outline of lobules

indicates pathology (except pigs)

Question 6

blood flow to the liver

Answer 6

dual blood supply:
- hepatic artery
- portal vein

Question 7

hepatic artery

Answer 7

brings oxygenated blood directly from the heart

Question 8

portal vein

Answer 8

brings deoxygenated blood from elsewhere in the body

supplies largest volume of blood to the liver

Question 9

hepatic sinusoids

Answer 9

fenestrated sinuses between rows of hepatocytes that allows for nutrient exchange, absorption, and product secretion

allows for mixing of blood between hepatic artery and portal vein

Question 10

central vein

Answer 10

located in the center of each liver lobule; receives nutrient rich blood after is passes through sinusoids

carries blood to hepatic vein

Question 11

hepatic vein

Answer 11

takes blood away from liver to heart

Question 12

hepatic acinus

Answer 12

functional unit of the liver that spans from hepatic train to central vein

divided into 3 zones

Question 13

hepatic triad

Answer 13

hepatic artery + portal vein + bile duct

Question 14

zone 1

Answer 14

periportal zone; located closest to hepatic triad

receives most oxygen and nutrient rich blood

Question 15

zone 3

Answer 15

centrilobular zone; located closest to central vein

receives deoxygenated blood

site of drug metabolism

Question 16

rate of blood flow through the liver

Answer 16

must remain constant

Question 17

main regulator of blood flow

Answer 17

hepatic artery

uses adenosine washout

Question 18

effect of adenosine on hepatic blood flow

Answer 18

inhibits vasoconstrictors to cause hepatic artery to dilate

does NOT affect portal vein

adenosine gets washed away by venous and arterial flow

Question 19

adenosine washout

Answer 19

maintains constant rate of blood flow

as portal vein flow increases –> adenosine gets washed away quickly –> hepatic artery constricts –> hepatic artery flow decreases

as portal vein flow decreases –> adenosine remains longer –> hepatic artery dilates –> hepatic artery flow increases

Question 20

affect of liver disease on blood flow

Answer 20

liver disease causes ascites :
1. hypoalbuminemia –> decreases oncotic pressure –> water flows out of vessels –> ascites
2. decreased hepatic blood flow –> increased hydrostatic pressure In portal vein – leakage –> ascites

Question 21

hepatocytes

Answer 21

functional unit of the liver; maintains plasma oncotic pressure by producing albumin, stores glycogen, vitamins, copper, and iron

has abundant mitochondria

Question 22

hepatocyte polarity

Answer 22

basal side: (top and bottom) faces sinusoids
apical side: (between hepatocytes) faces bile canaliculi

Question 23

kupffer cells

Answer 23

macrophages in the liver

Question 24

enzymes that indicate cell injury

Answer 24

ALT, AST, GGT

(leakage enzymes)

Question 25

acute phase proteins

Answer 25

albumin, bilirubin, glucose, cholesterol, blood urea nitrogen

assess liver function