10. functions of the Liver Flashcards
the LIVER is the LARGEST SOLID ORGAN in the body with what WEIGHT
1.5 KG
(rugby ball)
WHERE is the LIVER
RIGHT UPPER QUADRANT
under RIBS, Diaphragm ‘roof’
LIVER has how many SEGMENTS
8
- each have their own blood supply and bile drainage
what SUPPLY BLOOD IN to the LIVER
- HEPATIC ARTERY
(heart) - PORTAL VEIN from Intestines and Spleen
LIVER takes about 75% (MOST) of its BLOOD SUPPLY FROM…
HEPATIC PORTAL VEIN
from INTESTINES and SPLEEN
VENOUS DRAINAGE of LIVER by..
HEPATIC VEIN
(to IVC, to HEART)
BILE DRAINAGE BILIARY TREE consists of:
RIGHT and LEFT HEPATIC DUCT from liver
- COMMON HEPATIC DUCT
joins with CYSTIC DUCT from GALLBLADDER
-> COMMON BILD DUCT
(joins with pancreatic duct and secretes into duodenum via Ampulla)
LIVER is ARRANGED in..
LOBULES
each LIVER LOBULE has a … that DRAINS it
CENTRAL VEIN
- SURROUNDED by PORTAL TRIADS
what does a PORTAL TRIAD CONSIST of
- PORTAL VEIN branch
- HEPATIC ARTERY branch
- BILE DUCT
LIVER CELLS:
- 60% HEPATOCYTES
- 30% KUPFFER CELLS
- STELLATE CELLS
- ENDOTHELIAL CELLS
- BILIARY EPITHELIUM (in bile ducts)
what is the name of the PATH from the PORTAL TRIAD TO the CENTRAL VEIN (Portal Vein and Hepatic Artery blood travels through on the way to central vein)
SINUSOID
- FENESTRATED DISCONTINUED CAPILLARIES
LIVER ACINUS is the FUNCTIONAL UNIT of MICROCIRCULATION
it has 3 ZONES:
ZONE 1 - closest to portal triad
O2 RICH, OXIDATIVE METABOLISM
ZONE 2
- TRANSITION zone
ZONE 3- closest to central vein
LOW O2, ANAEROBIC METABOLISM, DRUG METABOLISM
which ZONE of the ACINUS has the HIGHEST OXYGEN
ZONE 1
(zone 3 - low o2)
what takes place in ACINUS ZONE 1
OXIDATIVE METABOLISM
what takes place in ACINUS ZONE 3
ANAEROBIC METABOLISM,
DRUG METABOLISM CP450
what are the KUPFFER CELLS of the liver
Liver-Resident MACROPHAGES
- EAT UP:
ANTIGENIC MATERIAL,
SENESCING (dying) RBC
LIVER KUPFFER CELLS are CRUCIAL FOR…
CLEARING BACTERIA / endotoxins
from PORTAL VEIN (blood from gut - rich in bacteria)
what do KUPFFER CELLS Eat up
ANTIGENIC MATERIAL
SENESCING (dying) RBC
WHERE are KUPFFER CELLS in the liver
in SINUSOIDS
what is the ROLE of STELLATE CELLS of the liver
- STORE FAT
- STORE VITAMIN A (fat soluble)
- REGULATE the TURNOVER of ECM (proteins holding cell together)
what can STELLATE CELLS do UNDER STRESS (ie alcohol consumption, excess fat deposition)
STIMULATE INFLAMMATORY CYTOKINES
- leading to FIBROSIS
(LAYER EXTRA ECM)
what do STELLATE CELLS STORE
FAT and VITAMIN A
WHERE are STELLATE CELLS in the liver
PERISINUSOIDAL SPACE - end of SINUSOIDS
in SPACE OF DISSE
what do STELLATE CELLS REGULATE the TURNOVER of and what can it cause
ECM
can cause FIBROSIS in stress/inflammation
what do HEPATOCYTES DO
LIVER FUNCTIONS
- PROTEIN, LIPID, CH20 (CARBOHYDRATE) METABOLISM
- BILE, CHOLESTEROL, STEROID Hormones METABOLISM & SYNTHESIS
- DRUG METABOLISM
- PROTEIN SYNTHESIS
HEPATOCYTES make up how much of LIVER CELLS
60 - 80 %
which LIVER CELLS make up 30%
KUPFFER CELLS (macrophages)
list some LIVER FUNCTIONS
-METABOLISM
of NUTRIENTS, BILIRUBIN, DRUGS, HORMONES
- DETOXIFICATION
of DRUGS, TOXINS, Hormones - STORAGE
of MINERALS and VITAMINS - ENDOCRINE functions
activation VIT D, T4 -> T3 Conversion, Angiotensinogen, metabolism - IMMUNE FUNCTIONS
Antigen Presentation, Phagocytosis (kupffer cells), filtering portal blood Bacteria - EXCRETION (BILE)
- SYNTHESIS (PROTEINS)
what can LIVER do to DRUGS as they PASS
DETOXIFICATION
and Phase 1 METABOLISM
how does LIVER have role in CARBOHYDRATE (CH20) METABOLISM
- by which PROCESSES:
- GLYCOLYSIS
BREAKING down glucose/sugars to release Energy - GLYCOGENESIS
glucose uptake to STORE as Glycogen - GLYCOGENOLYSIS
glycogen break down to RELEASE glucose - GLUCONEOGENESIS
MAKING glucose from new sources ie. fatty acids, lactate
ROLE of LIVER with LACTATE
MAIN ORGAN that CLEARS LACTATE
- uses in GLUCONEOGENESIS to form glucose -> glycogen
if high lactate, indicates acute liver failure
how does LIVER RECEIVE SUGARS
VIA PORTAL VEIN
- Fructose, Galactose, Lactose, Glucose
(GLYCOLYSIS)
LIVER REGULATES..
BLOOD GLUCOSE
where are GLYCOGEN STORES
MOSTLY LIVER
& MUSCLE CELLS
what PROTEINS does LIVER SYNTHESIS
- low levels can indicate liver problems
- CLOTTING PROTEINS
- AST/ALT (enzymes)
- ALKALINE PHOSPHATASE
- ALBUMIN
- COMPLEMENT PROTEINS
- CRP (inflammatory protein)
what does LIVER do in PROTEIN METABOLISM
- DETOXIFICATION of AMMONIA (lower levels)
(urea metabolism) - DEAMINATION of AMINO ACIDS
ORGANELLES that are important in LIVER FUNCTIONS
- SMOOTH ER
- ROUGH ER
- MITOCHONDRIA
- PEROXISOMES
LIVER ENZYMES:
- TRANSAMINASES
- PHOSPHATASES
- DEHYDROGENASES/HYDROXYLASES
- CYTOCHROMES OXIDO-REDUCTASES
in LIVER BLOOD TESTS, what proteins LEVELS would you look at
- AST
- ALT
- ALBUMIN
- PT / INR
- BILIRUBIN
- ALKALINE PHOSPHATASE
- GAMMA GT
ALT and AST are what types of ENZYMES
TRANSAMINASES
AST and ALT LEVELS MARK /INDICATE what
INFLAMMATION
and Hepatocyte injury
- RELEASED by DAMAGED HEPATOCYTES
(AST also from skeletal and cardiac muscles)
what are ALBUMIN and PT / INR LEVELS MARKERS OF
LIVER FUNCTION
- 1st blood test to go wrong with liver damage
-> indicate some liver inflammation which stops liver functioning
LOW ALBUMIN LEVELS are a GOOD MARKER of..
CHRONIC LIVER DAMAGE
ALBUMIN HALF LIFE:
20 DAYS
(long)
stays normal for 20 days even if liver damage
what does PT LEVELS MARK and what does it show
ACUTE AND CHRONIC LIVER DAMAGE
- REFLECTS CLOTTING ENZYMES produced by liver
- CLOTTING TIME
what do BILIRUBIN, ALKALINE PHOSPHATASE and GAMMA GT LEVELS MARK
CHOLESTATIC LFTs
- mark STASIS (STOPPING) of BILE FLOW
what is BILIRUBIN
formed from BREAKDOWN of RBCS and EXCRETED AS BILE
so high levels mark bile flow stasis
what can cause INCREASE in ALKALINE PHOSPHATASE LEVELS
BILIARY OBSTRUCTION
but also
PREGNANCY - released by PLACENTA
BONE DAMAGE - released
GAMMA GT (enzyme) LEVELS can be ELEVATED due to..
ALCOHOL or CHOLESTASIS (BILE FLOW STASIS)
