Post Absorptive Meachanisms

Question 1

What happens to glucose once it is absorbed?

Answer 1

It travels to the liver via the hepatic portal vein

It is then either stored in the liver or adipocytes
Insulin is secreted by the Beta cells of the islets of langerhans. It facilitates the uptake of glucose by the liver which is then converted into glycogen.
In adipocytes it can be converted into triglycerides

Note glycogen can be stored in the muscles

Or transported to the muscles or brain to be used as a respiratory substrate and RBCs (Red blood cells rely on glucose for energy and convert glucose to lactate)

Question 2

What happens to a.as once they are absorbed?

Answer 2

AA - used to produce protein, hormones etc or can be sued as a respiratory substrate

Question 3

How are the body’s glucose levels maintained by the body in a fasting state?

Longer fasting state?

Answer 3

Glucagon breaks down glycogen in the liver into glucose (gluconeolysis). This glucose can then be used by the brain, RBCs etc

After the glycogen stores are sued up, gluconeogenisis can occur (no carbs to glucose), which can then be used by the brain RBCs etc

Question 4

What happens too fast during the fasting state?

Lung time

Answer 4

Glucagon will promote the breakdown if triglycerides

Forming glycerol and fatty acids

Glycerol can form glucose in the liver, Fatty acids can be used to form ketones due to excess Acetyl- CoA

This whole process is known as lipolysis = breakdown of fat

Ketones can be used by the brain
Glucose used in RBCs as they cant use ketones

Question 5

What homes affect fuel metabolism?

Answer 5

GH 
Thyroxine increases metabolism 
Adrenaline - AG
Noradrenaline - AG
Cortisol - AG 
Insulin 
glucagon

Question 6

Definition of anabolic =

Catabolic =

Answer 6

Anabolic = building + maintaining

Catabolic = breaking down - losing mass

Question 7

Obesity affects on health:

X 5

Answer 7

Increased risk of heart disease, stroke, spheres ion, type 2 diabetes, liver disease, cancer

Obesity is becoming a growing issue

Question 8

Role of leptin and ghrelin on appetite?

Answer 8

Leptin:
In a person with a normal weight it surpasses the appetite

However, in those with obesity you can become leptin resistant therefore your petite is not suppressed

Ghrelin - increases before meals and stimulates an appetite. You can get abnormal stimulating leading to an increased appetite

Question 9

Is insulin catabolic or anabolic?

Answer 9

Anabolic, the rest are catabolic

Question 10

What is weight determined by?

Answer 10

Energy intake and expenditure
Genetics
Environment