Transcript H.4 Liver - SP New Moodle

Liver Anatomy
Figure 21-19: The hepatic portal system
IB ASSESSMENT
STATEMENT
H.4.1 Outline the circulation of blood
through liver tissue, including the hepatic
artery, hepatic portal vein, sinusoids and
hepatic vein.
Blood and
Bile Flow
Through the
Liver
Blood flow of the Liver
• Hepatic Artery delivers oxygenated
blood to the liver.
• Blood leaves the liver by the hepatic
Vein
• Hepatic portal vein bring blood to the
liver from the small intestine.
Blood Flow in the Liver
• Arterial blood mixes with that from the hepatic portal
vein as it flows through the blood-filled channels
known as the sinusoids.
• Sinusoids differ from capillaries because there are no
walls separating the blood from the liver cells.
• Thus blood are indirect contact with the blood cells
• The sinusoids are lined with phagocytic cells that
ingest old red blood cells
Blood flow in the Liver
Animation
• https://www.youtube.com/watch?v=P5_
BxsbmXcA
Structure of Liver Animation
• https://www.youtube.com/watch?v=GnibhGE7PI
• http://www.healthline.com/human-bodymaps/liver#1/8
IB Assessment Statements
• H.4.3 Explain the role of the liver in
regulating levels of nutrients in the
blood.
• H.4.4 Outline the role of the liver in the
storage of nutrients, including
carbohydrate, iron, vitamin A, and
vitamin D.
Functions of the Liver
• Storage
– Glycogen, fat, vitamins, copper and iron.
Hepatic portal blood comes to liver from
small intestine.
• Nutrient interconversion
– Amino acids to energy producing
compounds
– Hydroxylation of vitamin D. Vitamin D
then travels to kidney where it is
hydroxylated again into its active form
Liver as a storage organ
• Liver stores:
– Iron
– Carbohydrates (glycogen)
– Fat Soluble Vitamins (A, B12, D, and K)
IB Assessment Statement
• H.4.5 State that the liver synthesizes
plasma proteins and cholesterol
Functions of the Liver
• Synthesis
–Albumins, fibrinogen, globulins,
heparin, clotting factors
IB Assessment Statement
• H.4.7 Describe the process of
erythrocyte and hemoglobin breakdown
in the liver, including phagocytosis,
digestion of globin and bile pigment
formation.
Composition of Bile
• A yellow-green, alkaline solution containing
bile salts, bile pigments, cholesterol,
neutral fats, phospholipids, and
electrolytes
• Bile salts are cholesterol derivatives that:
– Emulsify fat
– Facilitate fat and cholesterol absorption
– Help solubilize cholesterol
Regulation of
Bile Release
Figure 23.25
Bile Flow around the Liver
• Bile is completely isolated from the blood via bile
channels
• Bile channels are composed of two rows of liver
cells
• Bile is produced in the liver and brought to the gall
bladder for storage via the bile ducts.
• Bile ducts are channels that carry bile.
IB Assessment Statement
• H.4.8 Explain the liver damage caused
by excessive alcohol consumption
H.4.7: Liver damage caused by excessive alcohol
consumption
• Liver damage occurs as a result of
excessive and prolonged alcohol use.
• There are three stages of liver damage
which includes fat accumulation leading to
liver inflammation then cirrohsis of the
liver.
• The breakdown of alcohol occurs in the
liver and the resulting breakdown products
of alcohol are toxic to the liver cells.
IB Assessment Statement
• H.4.6 State that the liver has a role in
detoxification.
Functions of the Liver
• Bile production: 600-1000 mL/day. Bile salts (bilirubin), cholesterol,
fats, fat-soluble hormones, lecithin
– Neutralizes and dilutes stomach acid
– Bile salts emulsify fats. Most are reabsorbed in the ileum.
– Secretin (from the duodenum) stimulates bile secretions,
increasing water and bicarbonate ion content of the bile
• Storage
– Glycogen, fat, vitamins, copper and iron. Hepatic portal blood
comes to liver from small intestine.
• Nutrient interconversion
– Amino acids to energy producing compounds
– Hydroxylation of vitamin D. Vitamin D then travels to kidney
where it is hydroxylated again into its active form
• Detoxification
– Hepatocytes remove ammonia and convert to urea
• Phagocytosis
– Kupffer cells phagocytize worn-out and dying red and white blood
cells, some bacteria
• Synthesis
– Albumins, fibrinogen, globulins, heparin, clotting factors