Term
| What are the three major blood supplies to the pancreas? |
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Definition
1. Celiac Artery 2. Splenic Artery 3. Superior Mesenteric Artery |
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Term
| Is the pancreas an endocrine or exocrince gland? |
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Definition
Both! Haha I Romito-ed you! Exocrine (For digestion-through a series of ducts) Endocrine (DUCTLESS!- Like all endocrine) |
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Term
| What cells produce insulin and glucagon, how many do people normally have, and where (SPECIFICALLY) are they located? |
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Definition
Islets of Langerhans Approximately 1 million Concentrated in the tail region of the Pancreas |
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Term
| What type of Islets of Langerhans cells produce insulin, what is their % of the total Islet Count? |
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Definition
| Beta Cell produces Insulin and Amylin and composes about 60% of total Islets |
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Term
| What type of Islets of Langerhans cells produce glucagon, what is their % of the total Islet Count? |
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Definition
| Alpha cells produce glucagon and they compose about 25% of islets |
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Term
| What are the four major types of Islet of langerhans cells and the hormones they produce? |
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Definition
Alpha Cell-Glucagon (25% of islets) Beta Cell- Insulin and Amylin (60%) Delta- Somatostatin (10%) F cell- Pancreatic and Polypeptide (1%) |
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Term
| What type of langerhan's cell composes the bulk of the core of the islets? |
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Definition
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Term
| What is a common characteristic of all endocrine glands? |
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Definition
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Term
| Where does GLUT2, which transport glucose into Beta cells, reside? |
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Definition
In the canaliculi between the cells "Oh Geez Babs, what a nice place to take a nap!" :-) |
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Term
What is the major site for GLUT-2? How about GLUT-4? |
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Definition
GLUT-2 is found in the Liver, B-Cells, kidney, and small intestine. (Low affinity, high capacity glucose transporter) GLUT-4 is found in muscle and fat The insulin-responsive glucose transporter |
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Term
What is the purpose of insulin? What are the 3 major targets? |
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Definition
purpose of insulin is to allow cells to utilize glucose from nutrients for the purpose of energy production and if in excess, the storage of those nutrients. 1. Liver 2. Muscle 3. Fat |
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Term
| What class of hormone is insulin? |
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Definition
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Term
| How can C-peptide serve as a marker for insulin production? |
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Definition
Insulin is composed of A and B segment connected by a disulfide bond. The C-segment is separated and is present in equal ammounts. The C-peptide not extracted by the liver...makes a good marker for insulin secretion |
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Term
| Describe the INCRETIN effect |
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Definition
When glucose is administered orally there is a much higher insulin response then a IV glucose drip. It’s due to the fact that by consuming the glucose orally and going through the digestive tract, gut hormones actually heighten the sensitivity of the beta cells to the glucose |
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Term
List the steps of Insulin Secretion VERY IMPORTANT TO KNOW! |
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Definition
1. Glucose is transported by facilitate diffusion (GLUT-2 in caliculi) into beta cells 2. Glycolytic Activity increases ATP in cell 3. ATP-dependent K+ channels close 4. Depolarization and opening of voltage gated Ca++ channels. 5. Calcium influx + second messengers (DAG, IP3, cAMP) cause insulin secretion. |
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Term
| List some stimulators of Insulin Production |
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Definition
1. High blood glucose (Most important) 2. Amino acids and fatty acids 3. GI hormones (incretin effect) 4. Ach 5. Parasympathetic NS 6. Sulfonylureas (Drug) |
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Term
| List some inhibitors of insulin production |
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Definition
1. Somatostatin 2. Epinephrine and NE 3. Sympathetic NS |
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Term
| What kind of receptor is the insulin receptor and describe how it works. |
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Definition
It is a protein kinase receptor, specifically TYROSINE KINASE RECEPTOR When insulin binds to the alpha subunit of this receptor, the receptor is activated, you have an activated hormone-receptor complex, and the beta subunit autophosphorylates. This interacts with the family of Insulin receptor substrates (IRS 1-6) the most studied is IRS-1 |
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Term
| What is the effect of insulin on proteins? |
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Definition
| It increases the uptake of a.a. into target cells for teh production of proteins. |
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Term
| Where is amylin secreted from and what is its function? |
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Definition
Amylin is secreted from the beta-cells of the islets of langerhans (just like insulin) It supresses postcrandial glucagon secretion (slows gluconeogenisis in the liver) which gives insulin a chance to catch up and balance out blood glucose with insulin secretion. |
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Term
| Where is glucagon secreted from and what is it major function? |
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Definition
This catabolic hormone is produced in the alpha cells of the islets of langerhans in the pancreas. Its main target is the liver where it acts to mobilize glycogen, fat, and protein during times of hypoglycemia. |
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Term
| What are stimulators of glucagon secretion? |
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Definition
Hypoglycemia Amino Acids (also activates insulin) Ach Sympathetic response (Epi and NE) |
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Term
| What are the inhibitors of Glucagon secretion? |
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Definition
Fatty Acids Insulin Somatostatin |
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Term
| Describe somatostatin and its function with insulin and glucagon |
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Definition
Somatostatin is a peptide hormone and is basically the "Buzz Killington" of the endocrine system. It inhibits both insulin and glucagon secretion |
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Term
| What processes does glucagon use to produce glucose from carbohydrates in the liver? |
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Definition
1. Glycogenolysis of Glycogen 2. Gluconeogenesis from the TCA cycle Both processes produce glucose |
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Term
What is the action of glucagon on fat metabolism in the liver? |
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Definition
Tryglycerides are broken down into their fatty acid components by Hormone Sensitive Lipase. The fatty acids are then converted into Ketone Bodies which are used as energy. |
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Term
| What is the action of glucagon on protein metabolism in the liver? |
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Definition
| Protein is degradated into amino acids, then gluconeogenisis converts them into glucose...SHAZAAAAM |
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Term
| In the fed state, what is the ratio of insulin to glucagon (which is higher) |
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Definition
Insulin is much higher Glucagon would be suppressed. |
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Term
In the fasting state what is the ratio of insulin to glucagon? Which would be higher? |
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Definition
Glucagon would be much higher (hypoglycemia) Insulin would be low (suppressed) |
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Term
| Are there more cases of Type I or Type II diabetes? |
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Definition
Much more Type II Diabetics!!! 90% Type II 10% Type I |
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Term
What are the three types of diabetes. |
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Definition
Type I Complete beta cell insufficiency -autoimmune destruction of beta cells -limited genetic basis Type II Dual defect of peripheral insulin resistance and pancreatic insufficiency Gestational Diabetes Mellitus -Glucose intolerance of variable severity with onset or first recognition of pregnancy. FYI: Diabetes insipidous is technically a type of diabetes but is unrelated b/c it has nothing to do with glucose regulation, insulin, glucagon, or the pancrease. It is due to lack of ADH/AVP |
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Term
| Which has a high genetic link, Type I or Type II diabetes? |
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Definition
Type II Also influenced by being a fatty |
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Term
| Discuss the mechanisms for Type II DM |
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Definition
1. Peripheral insulin resistance decrease in # of insulin receptors decrease in post-receptor activity 2. Inadequate insulin secretion still producing, insufficient ultimately beta-cells fail |
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Term
| Name 3 ways to diagnose diabetes |
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Definition
1. Random glucose test over 200 mg/dl 2. Fasting blood glucose over 126 mg/dl 3. OGGT (Oral Glucose Tolerance Test) Fast over night, give glucose dose and test two hours later and its over 200 mg/dl |
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