Lecture 8: Endocrine Physiology- Control of SerumGlucose and Calcium

Question 1

What happens in a fasted state metabolism with glucose and proteins

Answer 1

• 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

Question 2

What happens in a fasted state metabolism with lipids?

Answer 2

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

Question 3

What is ketone bodies used for? What happens if we have too many?

Answer 3

• Used for energy
• In T1D-> too many lead to ketacidosis b/c pH is too acidic

Question 4

Fasted state:

• Liver glycogen becomes _
• Adipose lipids becomes _ _ _ and _ that enter blood

Answer 4

• Liver glycogen becomes glucose
• Adipose lipids becomes **free fatty acids **and glycerol that enter blood

Question 5

Brain can use only _ and _ for energy

Answer 5

glucose and energy

Question 6

Mucles _ can be used for energy. What can muscle also use?

Answer 6

• Glycogen
• Muscles can also use fatty acids that enter the blood

Question 7

What happens in T2D

Answer 7

liver cont. to produce glucose even through high levels of glucose (no signal sent)

Question 8

What does endocrine pancreas secretes what type of hormones

Answer 8

• insulin by beta cells
• glucagon by alpha cells in the islets of langerhans

Question 9

How is metabolism primarily controlled?

Answer 9

by the ratio of these hormone: insulin, glucagon

Question 10

What do alpha cells secrete? D cells? beta cells?

Answer 10

• a: glucagon (used for hypoglyciema)
• D: somatostatin
• Beta: insulin, amylin

Question 11

What dominates in the fed state?

Answer 11

Insulin
* increase oxidation
* increase glycogen synthesis
* increase Fat synthesis
* increase protein synthesis

Question 12

What dominates in the fasted state

Answer 12

glucagon
* increase glycogenolysis
* increase gluconegensis
* increase ketogenesis

Question 13

Explain how your glucose, glucagon and glucose levels are before and after a meal

Answer 13

Question 14

What are factors that control insulin secretion?

Answer 14

• 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)

Question 15

Explain what happens in this picture

Answer 15

Question 16

Answer 16

Question 17

insulin promotes _

Answer 17

Anabolism
* Enhances cellular utilization & storage of glucose
* Enhances utilization of amino acids
* Promotes fat synthesis

Question 18

What is one way to increase glycose transport into most, bu not all, insulin senstivie cells

Answer 18

excerising skeletal muscle

Question 19

What does glucagon prevent? What is the antagonist of glucagon?

Answer 19

• Glucagon prevents hypoglycemia
• Antagonist to insulin

Question 20

• Explain the mechanism of action of insulin and how it works at a receptor level.
• Explain what happens with skeletal muscle+adipose too

Answer 20

• 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

Question 21

• Explain the mechanism of action of insulin and how it works at a receptor level. ( skeletal muscle+adipose )

Answer 21

• 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

Question 22

Explain what happens in a fasted state in adipose and restin skeletal muscle

Answer 22

In the absence of insulin, there are no GLUT4 transporters in the membrane

Question 23

at 25C what form is glucose in?

Answer 23

Question 24

at 25C what form is glucose in?

Answer 24

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

Question 25

What happens in the fasted state with the liver

Answer 25

heptocytes makes glucose and transports it out into the blood using GLU2 transporter

Question 26

what happens in the fed state in the liver

Answer 26

Insulin binds to tyrosine phosphate receptor and glucose gradient reverses to cause glucose to enter the hepatocytes through the GLUT2 -> singal cascade-> hexokinase phophoralates glucose to keep intracellular glucose low

Question 27

Fill it in

Answer 27

Question 28

What is diabetes mellitus and what does it cause?

Answer 28

• Characterized by abnormally elevated plasma glucose concentrations, i.e., hyperglycemia
• Can cause many complications including damage to blood vessels, eyes, kidneys, & nervous system

Question 29

What is type one and two diabetes characterized by? how is it diagnosed

Answer 29

• Type1:characterized by insulin deficiency from beta cells destruction
• Type2: characterized by insulin-resistance
• Diagnosed by testing blood glucose concentrations & glucose tolerance test