The Gastrointestinal System

Question 1

What are the main functions of the small intestine?

Answer 1

• Absorbs nutrients and proteins.
• Produces lactate.
• Crohn’s can affect absorption and therefore leads to mineral deficiencies.

Question 2

What are the main functions of the large intestine?

Answer 2

• Absorbs water and defecation.
• Produced lactate.

Question 3

What are the main functions of the liver?

Answer 3

• Metabolism (e.g. lactate)
• Synthesis
• Detoxification
• Storage and production of bile
• Clotting factors are produced here (e.g. DIC: Disseminated intravascular coagulation)

Question 4

What does the gallbladder do?

Answer 4

• It stores and releases bile to help the digestive system break down fat.
• To respond to intestinal hormones.

Question 5

What does the pancreas do?

Answer 5

• Produced pancreatic juice containing enzymes. This helps to digest food, particularly protein.
• It makes insulin, which helps to regulate blood glucose levels.

Question 6

How does your body control glucose?

Answer 6

• Glucose is the main source of energy for most cells in the body.
• The actions of hormones insulin and glucose helps to maintain the narrow range of glucose.
• Regulation of blood glucose is an example of homeostasis.
• Glucose is regulated through negative feedback.
• A rise in blood glucose levels triggers a release from beta cells in the pancreas.
• The pancreas contains a cluster of cells called the Islets of Lanlerhans, which contains alpha and beta cells.

Question 7

How is insulin released?

Answer 7

• Beta cells in the pancreas synthesise and release insulin.
• Insulin is released into the bloodstream acts on the liver, skeletal muscle, and adipose tissue by binding to the cells insulin receptors.
• This opens up glucose transporter proteins in the cell membrane and glucose, from the blood, is transported into the cells.
• This results in the overall decrease of glucose levels in the blood.
• The glucose is stored as glycogen in the liver and muscles, but stored as fat in the adipose tissue.

Question 8

How is glucagon released?

Answer 8

• If blood glucose levels drop, the alpha cells release the hormone glucagon.
• This causes the breakdown of glycogen into glucose by the liver.
• This breakdown is called glycogenesis.
• Glucose is released into the bloodstream to raise blood glucose levels.
• This suppresses the release of glucagon so that glucose doesn’t continuously be released.

Question 9

What is Type 1 Diabetes?

Answer 9

• Caused by the autoimmune destruction of the beta cells.
• Reduces the body’s ability to produce insulin.
• Often occurs early in life with a rapid onset.
• Thought to be associated with environmental triggers such as a virus.
• Effects around 10% of those with diabetes.

Question 10

What is Type 2 Diabetes?

Answer 10

• Progressive.
• Usually there is an insulin resistance so the body produces it but is unable to use it effectively.
• This is because the muscle, fat and liver cells do not respond effectively.
• Risk factors include: obesity, physical inactivity; ethnicity.
• High blood sugars can cause development in beta cell failure, leading to reduced insulin release and high BM’s.

Question 11

What is Diabetic Ketoacidosis (DKA)?

Answer 11

• Develops when there are 3 elements: Hyperglycaemia, Ketonemia, Ketonuria.
• When insulin deficiency develops the body is unable to use glucose for energy.
• Instead, fat stores are broken down and fatty acids are released for energy.
• Excessive amounts of regulatory hormones are released which stimulates glycogenolysis (breakdown of glycogen into glucose in the liver.
• The liver also produces glucose.
• Therefore this leads to hyperglycaemia.
• Free fatty acids are converted to ketones by the liver and released into the bloodstream.
• Ketones, containing acetone are acidic and lower the PH of the blood causing acidosis.

Question 12

When Potassium is Low is the PH High or Low?

Answer 12

High PH.

Question 13

What Potassium is High is the PH High or Low?

Answer 13

Low PH.

Question 14

What are the key priorities in DKA?

Answer 14

• Correction of dehydration
• Clearance of ketones
• Correction of electrolyte imbalance

Question 15

What is Hyperosmolar Hyperglycaemic State (HHS)?

Answer 15

• Medical emergency.
• Can be due to undiagnosed T2DM or T1DM complicated by illness that causes reduced fluid intake.
• Higher mortality rate than DKA.
• Significant illness can cause a reduction of circulatory insulin.
• Can cause cerebral oedema and pontine myelinolydsis.

Question 16

Why do we use fixed rate insulin (FRII) ?

Answer 16

• Insulin suppresses ketogenesis and reduces blood glucose, and corrects electrolyte disturbance.
• The goal is to halt the production of ketones.
• Once the BGL drops below 14mmol/l then glucose 10% should be commenced to prevent hypoglycaemia.

Question 17

What are the key messages from a Diabetic Specialist Nurse?

Answer 17

• Long acting insulin must continue in ICU.
• Always consider the precipitating cause of DKA and treat this.
• Always consider how you are navigating your feeding regime with insulin.
• When stopping IV insulin you increase the risk of DKA.
• Must restart subcut insulin in good time. As it takes time to get into the system.