1. Human Digestion and Nutrition
Liver – Organ of many functions

2. Liver Overview Football-sized in upper right abdomen
Largest organ by weight (~3 lbs.)
“Swiss Army Knife”
Performs functions related to:
Digestion
Excretion
Metabolism
Carbohydrates
Fats
Proteins

3. Liver and Blood Blood enters liver from two sources
From intestines through portal vein
Includes all absorbed nutrients
Some are processed/altered
Some are released directly
From heart through hepatic artery
Includes oxygen/nutrients for liver cells to perform their functions

4. Liver Functions – Digestion
Liver makes/ secretes bile
To gall bladder
Gall bladder makes/secretes bile salts
To small intestine
Bile salts break up large fat globules
Mechanical Digestion
Lipase breaks up small fat globules
Chemical Digestion
Glycerol and fatty acids
Absorbed to blood

5. Liver Functions – Carbohydrate Metabolism
High glucose – Glucose converted to glycogen
Low glucose - Glycogen converted to glucose
High glycogen – glucose stored as fat
Low glycogen – fat and protein converted to glucose
Regulated by hormones
Used primarily for cell respiration/energy production in all cells

6. Liver Function – Lipid/Fat Metabolism
Fatty acids converted to molecules used in cell respiration
Glycerol converted to molecules used in cell respiration
Fatty acid and glycerol are put together to make fat molecules for energy storage
Fatty acid and glycerol are put together to make fat molecules used in cell membranes
Used primarily for cell respiration and cell membranes in all cells

7. Liver Function – Protein Metabolism
Amino acids go directly to cells for protein synthesis
Amino acids used by liver to make proteins for blood
Amino acids converted to different amino acids as needed by cells
Amino acids converted to molecules for energy
Amino acids broken down for nitrogen to build DNA/RNA
Used primarily for protein synthesis in all cells

8. Liver Function - Excretion
Removes nitrogen compounds from amino acids and converts to urea
Removes and breaks down old/damaged red blood cells from blood
Removes toxins from blood – including alcohol and drugs (legal and illegal)
All of these products are filtered from blood by the kidneys and excreted in urine

9. Liver Functions
Liver Functions Video
Liver Ted Talk