Download IB 3 Liver - susanpittinaro

The Liver
Anatomy
 Largest
gland in the body (1.5 kg)
 Under the diaphragm, within the rib
cage in the upper right quadrant of
the abdomen
 Only human organ
that can selfregenerate
Anatomy
4
lobes
 Major:
left & right
 Minor: caudate &
quadrate
 Ducts
 Common
hepatic
 Cystic

From gallbladder
 Common

bile
Joins pancreatic duct at
hepatopancreatic ampulla
Anatomy
Blood flow
 Hepatic
artery
 Brings
oxygenated
blood to liver
 Hepatic
vein
 Carries
deoxygenated
blood away from the liver
 Hepatic
 Brings
portal vein
blood from small intestine
 Deoxygenated but full of nutrients
Blood flow
Hepatic portal vein divides into smaller
vessels called sinusoids
 Sinusoids eventually drain into the central
vein of the lobule

 Eventually

drains into the hepatic vein
Hepatic vein
drains into the
inferior vena cava
Bile production
Hepatocytes (liver cells)
secrete bile
 Bile is secreted into the
canaliculi

 To
the bile ductules
 To the common bile duct
 To the gall bladder

Storage
 To
the bile duct
 To the small intestine

Helps digest fats
Gallbladder anatomy
Thin-walled green muscular
sac
 On the inferior surface of the
liver
 Stores bile that is not
immediately needed for
digestion
 When muscular wall of
gallbladder contracts, bile is
expelled into the bile duct

Functions

The liver has more than 200 functions,
including:
 Regulation
of blood glucose & glycogen
 Storage of nutrients

Including iron, vitamin A, & vitamin D
 Breakdown
of erythrocytes
 Bile secretion
 Synthesis of plasma proteins

Incl globulins, albumin, prothrombin, & fibrinogen
 Synthesis
of cholesterol
 Detoxification of harmful substances
Functions
Normal blood glucose
= 90 mg/100 mL
 Liver pulls excess
glucose from blood
plasma and stores it
as glycogen
 As blood sugar levels
decrease, glycogen
reserves are converted
back to glucose

Functions
Adjusts amino acid
levels in blood
 Excess amino acids
are deaminated and
excreted through the
kidney

Functions
What gets broken down?
Insulin & other hormones
 Hemoglobin
 Toxic substances

 Alcohol

& drugs
Some antibiotics & hormones
 Including
estrogen & testosterone
Converts ammonia to urea
 Waste products are excreted through the
kidneys

Erythrocyte breakdown
Red blood cells have a life span of 120
days
 RBCs weaken and rupture, releasing
hemoglobin into the blood plasma

Erythrocyte breakdown


Hemoglobin is absorbed by phagocytosis by
Kuppfer cells in the liver
Hemoglobin is split into:
 Heme groups

Iron is removed from heme
Iron is carried to bone marrow
 Used for hemoglobin in new
RBCs


Remaining substance = bilirubin

Becomes bile pigment
 Globins

Hydrolyzed into amino acids and returned to blood
Erythrocyte breakdown
Problems with excessive alcohol
consumption


Metabolized alcohol may still be toxic to cells
Healthy liver cells are replaced with fibrous scar
tissue
 Reduces
ability to metabolize carbohydrates, fats, &
proteins
 Reduces ability to transport materials through the
body


Blood flow is blocked to and from the liver
Over time, this may lead to nutritional
deprivation & increased susceptibility to infection
Problems with excessive alcohol
consumption

Long term alcohol abuse results in 3 primary
effects on the liver:
– swelling of damaged liver tissue
 Fat accumulation
 Cirrhosis – build up scar tissue left in areas of liver
destroyed by prolonged alcohol exposure
 Inflammation
Any questions?