The pancreas and release of insulin

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  • Created by: Esme.B
  • Created on: 23-10-17 12:56
List the two main secretions of the pancreas?
1. Pancreatic juices containing enzymes=secreted into the small intestines. 2.Horomes secreted from the islets of Langerhans into the blood.
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What name is given to the group of exocrine cells that surround tiny tubules in the pancreas?
Acinus (plural acini)
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What is the first part of the small intestine called?
The duodenum
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What is the name of the inactive protease found in the pancreatic juice?
Trypsinogen (active form is trypsin)
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What is the name of the small patches of endocrine tissue in the pancreas?
Islets of Langerhans
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What hormone is secreted by the alpha cells?
Glucagon
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What hormone is secreted when blood glucose concentration is too high?
Insulin
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In the plasma membrane of beta cells are potassium ion channels normally open or closed?
open
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What enzyme is used in the metabolism of glucose in beta cells?
Glucokinase
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What causes the vesicles of insulin to fuse with the plasma membrane?
Calcium ions entering the cell when calcium ion channels open
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What process releases insulin from the beta cell?
Exocytosis
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why is the pancreas an unusual organ?
Has both exocrine+endocrine functions
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List an examples of Exocrine the pancreas undertakes?
1. pancreatic juices- amylase,Trypsinogen,lipase,soduim hydrogencarbonates - pancreatic duct carries juices to duodenum.
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List the functions of the 4 mains pancreatic juices?
1. amylase=carbohydrate that digests amylose to maltose 2.Trypsinogen= inactive protease,converted to active when enters duodenum3.Lipase=digests lips molecules 4.Na+ hydrogencarbonate=make alkaline, neutralises contents of digestive system.
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List an example of Endocrine the pancreas undertakes?
Islets of Langerhans contain=alpha (secretes Glucagon)+beta (secretes insulin) cells
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How do the Beta cells secrete insulin?
1 .K+ open =out of cell/Ca2+ closed 2.Glucose moves into cell,broken down to ATP 3 .K+ channel close-using ATP release a phosphate. 4.Ca2+open move in via facilitated diffusion=vesicles containing insulin to move. 5.inslusin removed by exocytosis.
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what two channels are involved in the secretion of insulin?
POTASSIUM and CALCUIM ion channels
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Why is it essential that insulin is not secreted in large amounts continuously?
This would reduce the blood glucose concentration too much. It will be secreted as log as the blood glucose concentration is too high. Once blood glucose drops to normal levels the secretion will stop.
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Distinguish clearly between exocrine and endocrine functions of the pancreas.
Exocrine function is to release enzymes via the pancreatic duct. These enzymes pass along the duct to the intestines to digest food. The endocrine function is to release hormones. Insulin and glucagon are released directly into the blood
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Suggest why the protease trypsin is released in the inactive form trypsinogen.
Active trypsin is a protease, so would digest any proteins in the cell and pancreatic duct. It is activated in the intestines.
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Other cards in this set

Card 2

Front

What name is given to the group of exocrine cells that surround tiny tubules in the pancreas?

Back

Acinus (plural acini)

Card 3

Front

What is the first part of the small intestine called?

Back

Preview of the front of card 3

Card 4

Front

What is the name of the inactive protease found in the pancreatic juice?

Back

Preview of the front of card 4

Card 5

Front

What is the name of the small patches of endocrine tissue in the pancreas?

Back

Preview of the front of card 5
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