Term
| Why is glucose regulated? |
|
Definition
| It is the major nutrient used by neural tissue. ~ 60% of basal glucose is utilized |
|
|
Term
| What is the normal concentration of glucose? What about 1-2 hrs after a meal? |
|
Definition
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|
Term
| Which organ gets 2/3 of the absorbed glucose and stores the excess as fuel? |
|
Definition
|
|
Term
| Besides the liver, what other organs are responsible for glucose control? |
|
Definition
Pancreas
Gut
Adrenals
Muscles
SNS |
|
|
Term
| Where does glucose come from? |
|
Definition
1. Intestinal absorption from the digestion of foodstuffs
2. Glycogenolysis
3. Gluconeogenesis |
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|
Term
| ___________________ is the source of 75% of glucose- "old or stored" |
|
Definition
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|
Term
| _______________ is the source of 25% of glucose "new" |
|
Definition
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|
Term
| Glycogenolysis is the breakdown of glycogen. Which tissues have glycogen? |
|
Definition
|
|
Term
| Out of the 3 tissues that have glycogen, which 2 are the only ones that can undergo glycogenolysis? |
|
Definition
Liver and Kidney
(The muscles want to keep there glucose) |
|
|
Term
| How much glycogen is stored in the muscles, kidney, liver? |
|
Definition
If active 3 hr supply
if not active then 8-15 hr supply |
|
|
Term
| Which enzyme is responsible for catalyzing the formation of glucose from G-6-P (derived from glycogen)? |
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Definition
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|
Term
Complete the following breakdown of gluconeogenesis:
______________ (from muscle) = 52% of gluconeogenesis
_________ = 4%
_____________ = 28%
_______________ = 16% |
|
Definition
Lactate
Pyruvate
Amino acid (mainly Ala)
Glycerol |
|
|
Term
| Which hormones tend to increase the blood glucose level? |
|
Definition
AKA Counter regulatory hormones
1. Epi
2. Glucagon
3. GH
4. Glucocorticoids like cortisol |
|
|
Term
| Which hormone is the only one to decrease the blood glucose level? |
|
Definition
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|
Term
| The pancreas is ________% exocrine and ________% endocrine. |
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Definition
|
|
Term
| Where is the pancreas located? |
|
Definition
| In the curve of the duodenum, posterior to the liver and stomach |
|
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Term
| What 2 major types of tissues make up the pancreas? |
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Definition
1. Acinar = exocrine portion
2. Islets of Langerhans = endocrine portion |
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Term
| Which type of tissue of the pancreas accounts for 98-99% of the weight? |
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Definition
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Term
| What 3 cell types account for 75% of the million islet cells of the pancreas? |
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Definition
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Term
| The alpha cells of the Islets of Langerhans make up ________% and makes __________. |
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Definition
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Term
| The Beta cells of the islets of langerhans make up _______% and makes both _________ and ________. |
|
Definition
40-60%
Insulin and amylin |
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Term
| The Delta cells of the Islets of Langerhans makes up _________% and makes ___________. |
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Definition
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Term
| The F cells of the Islet of Langerhans makes up 5-15% and is sometimes called pp cells. What does pp stand for? |
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Definition
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Term
| Parasympathetic innervation effects this enzyme _______________ located in the _________ and this NT is released _____________. |
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Definition
Glycogen Synthetase
Liver
ACH |
|
|
Term
| Where does sympathetic innveration occur in the pancreas? And what NT does it release? |
|
Definition
In the Alpha, Beta and possibly Delta cells of Islet of Langerhans.
Releases Epi and NE |
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Term
| Sympathetic innervation has its receptors located in the ___________. |
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Definition
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Term
| _____________ is a post translational product. |
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Definition
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Term
| T/F: There is paracrine effect in junctional gaps that modulate secretion. |
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Definition
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Term
| Insulin and the C-peptide are stored in _____________. |
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Definition
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Term
| Insulin is stored as a 51 aa peptide: ________21 a.a and _________ 30a.a chain connected by 2 disulfide bridges. |
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Definition
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|
Term
| Amount of insulin stored by the pancreas decreases with _____ and _________. But increases with ____________ and ________. |
|
Definition
Age and Fasting
Obesity and Pregnancy |
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Term
| Insulin release from the pancreas is stimulated by glucose ________ and __________. And occurs via exocytosis. |
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Definition
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|
Term
| What transporter on the pancreas is activated for insulin release? |
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Definition
| Glut-2 which pulls glucose into the cell |
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Term
| When glucose enters the cells it needs to be phosphorylated via _______ enzyme. |
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Definition
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|
Term
| ___________ stimulates the synthesis of insulin. |
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Definition
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|
Term
| Insulin is released in a _____________ manner. |
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Definition
|
|
Term
| T/F: The product of glucose metabolism closes the ATP sensitive K+ channel. This increases the Ca2+ influx. |
|
Definition
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|
Term
| The release of __________ reelases insulin via vagus stimulation. |
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Definition
|
|
Term
| What are inhibitors of insulin release? |
|
Definition
1. NE
2. Epi - via Alpha 2 Receptors, whcih lower the cAMP levels
3. Decrease in blood glucose
4. Somatostatin - decreases Ca2+ coupling |
|
|
Term
| T/F: Insulin is transported bound |
|
Definition
| False; it is in free form |
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|
Term
| ___________and ___________ metabolize about 80% of the insulin. |
|
Definition
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|
Term
| The C-peptide is a good estimate of ______________ and is not degraded. |
|
Definition
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|
Term
| How does insulin initiate physiological effect? |
|
Definition
By binding to high affinity specific receptors.
(only have to bind 5-10% to get activation)
After binding, a signal is transmitted thru a second messenger. |
|
|
Term
| What are other stimulis for insulin release? |
|
Definition
1. GI hormones
2. Glucagon
3. A.A.
4. Ketone Bodies
5. FFA |
|
|
Term
| What effects does insulin have on cAMP? Tyrosine kinase system? and Mg-activated Na-K-ATPase? |
|
Definition
decreases cAMP
Increases Tyr Kinase
Increase Na-K-ATPase |
|
|
Term
| Insulin increases intracellular ___________, and increases transport of K+, Mg, PO4 and A.A. |
|
Definition
Ca2+
(leads to the decrease in cAMP) |
|
|
Term
| What is the major action of insulin? |
|
Definition
| To increase the uptake of glucose at the tissue surface |
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Term
| ______________ is Ubiquitious, RBC. System operates close to max transport velocity. The Km is 5-10 mM which is at the physiological level of glucose. |
|
Definition
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Term
| Glut 2 levels are high in the __________, small intestine and ____________, and on the proximal tubules of kidney. |
|
Definition
Liver
Pancreatic Beta cells |
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|
Term
| The Km of Glut 2 transporter is 20-40 mM, this means low _______ so probably operates within the most linear part of its velocity substrate curve onver normal ranges. |
|
Definition
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|
Term
| Patients with Type 1 and 2 diabetes have a ____________ expression of Glut 2 Transporters. |
|
Definition
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|
Term
| What is the major glucose transporter in the brain? |
|
Definition
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|
Term
| The Km of Glut 3 is very low (1-5 mM) so it has a ____________. |
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Definition
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|
Term
| Not only is Glut 3 found in the brain but also in the _____________ and ___________. |
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Definition
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|
Term
| Glut 4 is aka ___________. |
|
Definition
|
|
Term
| Where are Glut 4 transporters located? |
|
Definition
| In adipose, skeletal and cardiac muscle |
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|
Term
| In obese and Type 2 diabetes patients, Glut 4 numbers are ___________. |
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Definition
|
|
Term
| T/F: Glut 4 transporters have a high turnover and insulin is continously recycled from cell to surface. |
|
Definition
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|
Term
| List the enzymes that insulin stimulates. |
|
Definition
1. Glycogen synthetase
2. Glucokinase
3. Glycerol kinase
4. Pyruvate kinase
|
|
|
Term
| List the enzymes that insulin inhibits. |
|
Definition
1. Glycogen phosphorylase
2. Glucose 6- Phosphatase
3. Gluconeogenic enzymes |
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|
Term
| Insulin has ____ effects on carbohydrate metabolism in the liver. |
|
Definition
|
|
Term
| How is glucose release from the liver decreased by insulin? |
|
Definition
1. There is a decreases in cAMP. To inhibit phophorylase enzymes
2. An increase in glycogen synthesis and glucokinase to store glucose
3. Inhibit gluconeogenic enzymes |
|
|
Term
| How does insulin promote glucose uptake in the muscle? |
|
Definition
1. Facilitative diffusion
2. Glut 4 transporters
3. Muscle has hexokinase enzyme |
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|
Term
| During exercise is insulin released? |
|
Definition
| No it is inhibited. (otherwise no release of stores) |
|
|
Term
| Is insulin needed for glucose to enter an exercising muscle? |
|
Definition
|
|
Term
| Can muscle use fat as an energy substrate? |
|
Definition
| Yes, uses fat since resting muscle is impreamble to glucose without insulin. |
|
|
Term
| The primary effects of insulin on blood glucose is to : |
|
Definition
1. Decrease hepatic glucose production
2. Increase peripheral glucose uptake |
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|
Term
| The effect of insulin on lipid metabolism is ___________. |
|
Definition
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|
Term
| There is an increase in glucose entry to adipocytes via __________. |
|
Definition
|
|
Term
| Why is there an increase of glucose into the liver? |
|
Definition
| Insulin stimulates glucokinase |
|
|
Term
| What affects does insulin have on A.COA carboxylase and a-glycerol PO4 in lipid metabolism? |
|
Definition
1. Increase in acetyl CoA carboxylase to increase FFA
2. Increase in a-glycerol phosphate to increase formation of glycerol for TG |
|
|
Term
| Insulin ________ the lipoprotein lipase that promotes the break dwon of TG into FFA and glycerol. |
|
Definition
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|
Term
| Insulin ____________ The hormone sensitive lipase (adipose cell lipase) whereas _____________cofactors for FFA synthesis like NADPH. |
|
Definition
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|
Term
| Generally speaking, insulin increases the synthesis and storage (______________) and decreases utilization (______________) of lipids. |
|
Definition
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|
Term
| The effects of insulin on protein metabolism are __________. |
|
Definition
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|
Term
| Insulin effects on protein metabolism is considered anabolic because they increase what? |
|
Definition
1. A.A. transport
2. Protein synthesis
3. RNA synthesis |
|
|
Term
| What is the synthetic analog of amylin? |
|
Definition
|
|
Term
| What are some of Symlin's features? |
|
Definition
1. Enchances the way insulin works
2. Slows rate of release of nutrients
3. Helps control appetite
4. Supresses Glucagon |
|
|
Term
| GLP-1 are made in the L cells of the GI tract. They enhance ______________ secretion in glucose dependent manner and ______________ glucagon secretion and delay gastric secretion. |
|
Definition
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|
Term
| In Type 2 diabetes patients there is a impaired secretion of _______ from the gut during a meal. |
|
Definition
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|
Term
| _____________ is an incretin mimetic for treatment of Type 2 diabetes. |
|
Definition
|
|
Term
| T/F: GLP-1 may also preserve beta pancreatic cell function. |
|
Definition
|
|
Term
| GLP-1 increases satiety thus _________ food intake. |
|
Definition
Decreases
(helps to lose weight in patients) |
|
|
Term
|
Definition
|
|
Term
| DPP4 inhibitors block the metabolism of GLP-1 thus there is more ___________ around. |
|
Definition
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|
Term
| _______________ is from the brain, increases food intake and insulin release and growth of beta cells. |
|
Definition
| Melanin concentrating hormone (MCH) |
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|
Term
| Resistins are __________ derived hormone so is __________ in obese, and insulin resistant animals. |
|
Definition
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|
Term
| ____________ compromise the action of insulin with its dominant effect is to reduce insulin's inhibitory action on the liver. |
|
Definition
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|
Term
| ____________and ___________ decrease synthesis of glucagon by repressing transcription of its gene. |
|
Definition
|
|
Term
| What things cause an increase in glucagon secretion? |
|
Definition
Most A.A. (Ala, Arg, Leu)
SNS |
|
|
Term
| What things inhibit the release of glucagon? |
|
Definition
1. Increase in cellular Ca2+
2. Increase in blood glucose
3. Somatostatin
4. Insulin |
|
|
Term
| What second messenger increases glucagon? |
|
Definition
|
|
Term
| Glucagon has opposite effects to that of insulin. So what enzymes does Glucagon stimulate for carbohydrate metabolism? |
|
Definition
1. Gluc-6-Phosphatase
2. Gluconeogenic enzymes
3. Glycogen phosphorylase
(all these break down glycogen stores)
(Only occurs in the liver) |
|
|
Term
| What enzymes does glucagon inhibit in carbohydrate metabolism? |
|
Definition
1. Pyruvate kinase
2. Glucokinase
3. Glycogen synthetase |
|
|
Term
| In general, in carbohydrate metabolism Glucagon stimulates ______________ and ____________. |
|
Definition
Gluconeogenesis
Glycogenolysis |
|
|
Term
| Glucagon is a ____________ hormone and can lead to hyperglycemia and ketone formation. |
|
Definition
|
|
Term
| What effects does glucagon have on lipid metabolism? |
|
Definition
| Increases hormone sensitive lipase which then increases cAMP and there is a shift of FFA from TG synthesis to B-oxidation. |
|
|
Term
What is the molar ratio of insulin:glucagon?
During fasting/exercise?
After a pure Carb meal? |
|
Definition
|
|
Term
| ______________ is the first biological product of mammal to be produced by recombinant DNA. It also has the shortest half life. |
|
Definition
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|
Term
| Somatostatin is an effective ___________of both glucagon and insulin. |
|
Definition
|
|
Term
| T/F: Glucagon functions to limit the maximal elevation of blood glucose under physiological conditions. |
|
Definition
| False; Somatostatin does this! |
|
|
Term
| What things increase the release of somatostatin? |
|
Definition
1. A.A.
2. Glucose
3. FFA
4. Glucagon
5. GI hormones |
|
|
Term
| What things decrease the release of somatostatin? |
|
Definition
|
|
Term
| Somatostatin is a very negative substance. What things does it reduce? |
|
Definition
1. Gastric empytying
2. Gastric secretions
3. Gall bladder contraction
4. Pancreatic exocrine function
5. Glucose absorption |
|
|
Term
| Somatostatins impair the uptake of ______________ by B-cell pancreas. |
|
Definition
|
|
Term
| Why would it be beneficial to administer somatostatin with insulin in a Type 1 diabetic? |
|
Definition
| It inhibits Glucagon and also lowers the postprandial glucose levels. |
|
|
Term
| Which A.A. stimulates all 3 islet hormones? |
|
Definition
|
|
Term
| High concentrations of FFA stimulate _____________ and inhibit ___________. |
|
Definition
|
|
Term
| ______________ increases sensitivity of glucagon. |
|
Definition
|
|
Term
| Catecholamines ____________ insulin/somatostatin and ____________ glucagon. |
|
Definition
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