Lecture 8: Endocrine Physiology- Control of SerumGlucose and Calcium Flashcards
What happens in a fasted state metabolism with glucose and proteins
- glycogen-> glucose via glycogenolysis
- Protein used to make ATP
* Deamination of aa to organic acids, pyruvate, acetyl coA, intermediates of the citric acid cycle
* Broken down with production of ATP
What happens in a fasted state metabolism with lipids?
Lipids broken down via
* glycerol feeds into glycolysis
* fatty acids undergo beta-oxidation to produce acetyl CoA
* Excess acetyl CoA become ketone bodies
* Strong metabolic acids lead to ketoacidosis
* ketogenic diets rich in proteins and fat low in carbohydrates
What is ketone bodies used for? What happens if we have too many?
- Used for energy
- In T1D-> too many lead to ketacidosis b/c pH is too acidic
Fasted state:
- Liver glycogen becomes _
- Adipose lipids becomes _ _ _ and _ that enter blood
- Liver glycogen becomes glucose
- Adipose lipids becomes **free fatty acids **and glycerol that enter blood
Brain can use only _ and _ for energy
glucose and energy
Mucles _ can be used for energy. What can muscle also use?
- Glycogen
- Muscles can also use fatty acids that enter the blood
What happens in T2D
liver cont. to produce glucose even through high levels of glucose (no signal sent)
What does endocrine pancreas secretes what type of hormones
- insulin by beta cells
- glucagon by alpha cells in the islets of langerhans
How is metabolism primarily controlled?
by the ratio of these hormone: insulin, glucagon
What do alpha cells secrete? D cells? beta cells?
- a: glucagon (used for hypoglyciema)
- D: somatostatin
- Beta: insulin, amylin
What dominates in the fed state?
Insulin
* increase oxidation
* increase glycogen synthesis
* increase Fat synthesis
* increase protein synthesis
What dominates in the fasted state
glucagon
* increase glycogenolysis
* increase gluconegensis
* increase ketogenesis
Explain how your glucose, glucagon and glucose levels are before and after a meal
What are factors that control insulin secretion?
- Increased plasma glucose
- Increased plasma amino acids
- Feed-forward effects of GI hormones (GLP-1 and GIP)
- Parasympathetic activity stimulates (ach)
- Sympathetic activity inhibits in time of stress (NE)
Explain what happens in this picture
insulin promotes _
Anabolism
* Enhances cellular utilization & storage of glucose
* Enhances utilization of amino acids
* Promotes fat synthesis
What is one way to increase glycose transport into most, bu not all, insulin senstivie cells
excerising skeletal muscle
What does glucagon prevent? What is the antagonist of glucagon?
- Glucagon prevents hypoglycemia
- Antagonist to insulin
- Explain the mechanism of action of insulin and how it works at a receptor level.
- Explain what happens with skeletal muscle+adipose too
- Insulin binds to the tyrosine receptor and phosphorates IRS (insulin-receptor substrates)-> activates second messengers to alter protein synthesis and existing proteins
- Then membrane transport is modified-> glut4 (for skeleton muscle and adipose) brings glucose into the cells
- Explain the mechanism of action of insulin and how it works at a receptor level. ( skeletal muscle+adipose )
- Insulin binds to the tyrosine receptor and phosphorates IRS (insulin-receptor substrates)-> activates second messengers to alter protein synthesis and existing proteins
- Then membrane transport is modified-> glut4 (for skeleton muscle and adipose) brings glucose into the cells
Explain what happens in a fasted state in adipose and restin skeletal muscle
In the absence of insulin, there are no GLUT4 transporters in the membrane
at 25C what form is glucose in?
at 25C what form is glucose in?
62% in bera pyranose
38% in alpha pyranose
0.5-2% in furanose
0.02%-> little bc it can be the cause of toxic effects of glucose
