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Role of the Liver
Do Now-Introductory Paragraph check-in
Homework Google Quiz will be available by 7:30 tonight and will go until Friday at
midnight On the Wikisite
The Liver “Renaissance Man” of the body
Important in digestion of fat Detoxifies drugs and alcohol Make cholesterol and proteins vital to the body
The Liver Blood is filtered through the liver
Liver filters out amino acids, fatty acids and glucose
Destroys bacteria that have made their way into the blood
Liver Function on Metabolism Maintains normal blood glucose level
100 mg/100 mL of blood
After eating heavy duty amount of carbs, liver removes glucose and stores as glycogen in the liver (glycogenesis)
Blood sugar levels will drop, and liver breaks down stored glycogen and releases it to the body (glycogenolysis)
Liver can also create glucose from fats and proteins, known as glyconeogenesis
Liver Function and Blood Sugar As blood sugar increases, glycogenesis converts glucose to glycogen and
stores it
As blood sugar falls, glycogenolysis breaks down stored glycogen, converts it to glucose and releases it to the blood
Cholesterol Only 15% comes from diet, 85% is made by the liver
High cholesterol is genetic
Cholesterol helps build plasma membranes of cells
Not soluble, can’t circulate freely in the blood
Transported by HDLs and LDLs
HDLs v. LDLs LDLs transports cholesterol to the body cells
Large amounts of LDLs circulated increases the risk of becoming imbedded in the arterial walls
HDLs transport cholesterol from the tissue to the liver to be disposed
HDLs “good”, LDLs “bad” But both necessary
Body Temperature Regulation
Heat Protecting Mechanism Hypothalamus in the brain regulated body temp to stay between 96-100
degrees
When body temp falls, the body must conserve heat Vasoconstriction
Blood vessels of skin shrink, preventing blood flow and keeping blood deeper, toward more vital organs
Shivering
Vasoconstriction Temporarily, vasoconstriction can be harmless
However, if vasoconstriction can eventually cause a deprivation of oxygen, thus causing skin cells to die (frostbite)
When vasoconstriction is no longer effective and core body temp drops, shivering starts Skeletal muscle activity produces lot of heat
Frostbite
Heat Releasing Mechanisms Most heat released through the skin (radiation)
If external environment is as hot as the body, heat cannot be lost by radiation, only evaporation of sweat
If weather is humid, evaporation is much less effective
Heat Stroke v. Heat Exhaustion Increased heat production, increases the rate of the metabolism
Skin becomes hot and dry, but is unable to lose heat via sweat
Heat stroke can cause permanent damage to the brain
Heat exhaustion is when an individual faints following physical activity, usually associated with dehydration
Homework Quiz tomorrow