Liver A&P

Liver location

right hypochondrium and epigastric region (RUQ**)

Liver Functions

-filters blood
-detoxifies chemicals
-metabolizes drugs
-produces bile

how many lobes does the liver have?

2

Falciform Ligament

separates the right and left lobes of the liver and attaches the liver to the anterior abdominal wall

the right lobe of the liver is divided into _______ and _______ lobes

caudate and quadrate

The round ligament is a remnant of the ___ ___

umbilical vein

Glisson Capsule

fibroelastic capsule innervated by lower intercostal nerves

Distension of Glisson capsule can cause pain in liver dz

Porta Hepatis

-opening or fissure
-portal vein, hepatic artery proper, and hepatic ducts enter/leave the liver

Arterial supply to liver

Celiac trunk > common hepatic artery > hepatic artery proper > right and left hepatic arteries which then carry oxygenated blood to liver

Venous supply to liver

Hepatic portal vein > right and left branches that enter parenchyma

Blood rich in substances absorbed from GI tract (deoxygenated blood)

Hepatic portal vein is a convergence of _____ vein and __________________ vein and recieves _____________ blood that contains nutrients, drugs, etc

splenic vein; superior mesenteric vein; deoxygenated blood

Venous supply from liver

venous blood from liver flows through hepatic vein into inferior vena cava

Liver Lobules

-multiple in the liver
-made of hepatocytes

Hepatocytes

-functional cells of liver capable of regeneration
-secrete electrolytes, lipids, cholesterol, lecithin, bile acids into bile canaliculi
-synthesize plasma proteins which can be released into bloodstream

What are small capillaries btwn hepatocytes?

Sinusoids
-receive mixture of venous and arterial blood from branches of hepatic artery and hepatic portal vein

Central Vein

-where blood from the sinusoids drain

-located in the middle of each liver lobule (which then drain into the hepatic vein)

Subendothelial Space/space of Disse

-located between hepatocytes and sinusoid
-drains interstitial fluid into hepatic lymph system

subendothelial space (Space of Disse) contains _________ that regulate sinusoidal blood flow, participate in liver fibrosis, remove foreign substances from blood and trap bacteria

lipocytes (stellate cells) - contains Vit A

Sinusoids are lined with ___ and ____

permeable endothelium and Kupffer cells (macrophages)

sinusoids enhance transport of nutrients into ____

hepatocytes

Sinusoidal endothelial cells have Natural Killer cells that are important in our tumor defenses

Bile

alkaline, bitter-tasting, yellowish green fluid

Bile contains bile salts + …………..

cholesterol, bilirubin, electrolytes, and water

Bile salts are required for intestinal emulsification and ____________________

Absorption of fats

bile and bile salts are formed by hepatocytes and secreted into ___________

bile canaliculi - which empty into bile ducts and eventually drain into common bile duct

Primary Bile Acid Pool

-cholic acid, chenodeoxycholic acid
-made from cholesterol by hepatocytes

Bile salts are mostly absorbed in the _______________ and return to liver by the ______

Terminal ileum; portal hepatic system

Secondary Bile Acid Pool

-deoxycholic acid, lithocholic acid
-formed in intestines by bacteria

Enterohepatic Circualtion

recycling of bile salts

Billirubin is produced by the

destruction of aged RBCs and gives bile a greenish color and yellow tinge of jaundice

Unconjugated bilibrubin is…

lipid soluble (free) bilirubin > can cross membranes

Conjugated bilirubin

water soluble bilirubin > allows it to be excreted from body

conjugated bilirubin is deconjugated by bacteria in the distal ileum and colon to ________

urobilinogen (gives urine its yellow color and feces its brown color)

Stercobilin

gives feces brown color

Urobilin

gives urine its yellow color

Liver Heme Functions

-stores and releases blood
-synthesizes clotting factors (prothrombin, Factors 7,9,10)

Vitamin K

-essential for synthesis of clotting factors
-absorption depends on adequate bile production

2 functions of Liver Fat Metabolism

-hydrolyzes triglycerides
-synthesizes phospholipids and cholesterol

Hydrolysis of Triglycerides

-triglycerides broken into glycerol and free fatty acids
-produces ATP
-can be released into the bloodstream bound to proteins (lipoproteins)

where lipoproteins are stored

adipose cells

Phospholipids and Cholesterol are needed to produce ____

bile salts, steroid hormones, components of plasma membranes

what consumes aged RBCs in the spleen and liver

Macrophages (Kupffer cells in liver)

Heme

broken down into biliverdin and iron

Iron

attaches to transferrin and is stored in liver or used by bone marrow to make new RBCs

Bilverdin

converted to unconjugated bilirubin and released into plasma

unconjugated bilirubin binds to ______ for transport to the liver

albumin

bilirubin has to be _______ to be secreted in the bile

conguated

Protein Function

-muscle contraction
-energy source
-fluid balance
-immune protection
-regulation of chemical reactions and hormones
-structural support
-transport of molecules
-coagulation

Deamination

the removal of ammonia which converts amino acids into carbohydrates

ammonia is converted to ______ and excreted in the kidneys

urea

The liver synthesizes ___ and ____

plasma proteins (albumin, a/b globulins) and nonessential amino acids and serum enzymes (AST, ALT, LDH, GGT, AP)

liver releases _______ in states of hypoglycemia

glucose

liver takes up ______ in states of hyperglycemia

glucose

the liver stores glucose as __________ or converts it to fat

glycogen (glycogensis)

when all glycogen stores have been used, amino acids and glycerol are converted to glucose. What it this called?

Gluconeogenesis

vitamin stored in greatest quantity in the liver

Vitamin A

**D, B12, E, and K also stored

Ferritin

-how iron is stored in the liver
-stored when iron levels are high
-released when iron levels are low

Hepatic cells contain ____ that reversibly binds with iron to form ferritin

apoferritin

Metabolic Detoxification of the Liver

-alters chemicals (drugs), foreign molecules, and hormones
-makes things less toxic or less active (dec reabsorption which promotes intestinal/renal excretion)
-protective usually . End products can become toxins( ETOH > toxins (acetaldehyde and hydrogen)