Endocrine Module

1b

Pancreas Gland

• 6” long• Horizontal• Behind stomach• Upper left abdominal

quadrant• Both endocrine &

exocrine functions

Endocrine Pancreas

• Islets of Langerhans• Alpha cells– Glucagon

• Beta cells– Insulin

• Delta cells– Somatostatin

Insulin• Produced and

secreted by…– Beta cells

Insulin• Primary function…– Stimulates the active

transport of glucose– from the blood into

muscle, liver and adipose tissue

– __?__ blood glucose levels•

Glucose Content of Food

• What % of the carbohydrates consumed breaks down into glucose?– 100%

• What % of the protein consumed breaks down into glucose?– 58%

• What % of the fat consumed breaks down into glucose?– 10%

Secretion of Insulin

• Is stimulated by:– What change in homeostasis does the sensor

identify and then stimulates the beta cells to secrete insulin?

– Hyperglycemia

• Glucose levels in the bloodstream regulate the rate of insulin secretion

The major action of insulin

• blood glucose levels• the permeability of target cell membrane to

glucose– Main target cells

• Muscle• Liver• Adipose tissue

Insulin info

• The glucose is either metabolized or stored • In the absence of insulin, glucose is not able to

get into the cells and it is excreted in the urine• Brain cells are not dependent on insulin for

glucose intake

Insulin

• Eat the glucose– Muscle energy

• Storage of glucose– Liver = freezer– Glycogen– Synthesis of Adipose tissue = 2nd freezer

• Give it away– Glycosuria

Other functions of Insulin

• Promote the conversion of glucose glycogen– Glycogenesis

• Also inhibits the conversions of glycogen glucose – Glycogenolysis

• Glycogen = the form in which glucose is stored in the liver

Other functions of Insulin

• Promoting the conversion of fatty acids fat– Adipose tissue

Other functions of Insulin

• Preventing the breakdown of fat ketone bodies

• Ketone bodies: the byproduct of fat metabolism

Other functions of Insulin

• Stimulating protein synthesis

• Inhibiting the breakdown of protein amino acids

Insulin Summary

• Insulin blood glucose levels• Promotes the storage of glucose• energy production from other

sources–Glycogen, fat or protein metabolism

Glucagon

• Produced and secreted by the – Alpha cells of the Islets of Langerhans

• Glucagon stimulates the release of– Glucose by the liver

Glucagon stimulates the release ofGlucose by the liver

• What “G” word means the release of glucose by the liver?

A.GlycogenB.GlycogenesisC.GlycogenolysisD.GlucoseE.Gone-is-my-brain

• The affect of glucagon– blood glucose level– Hyperglycemia

Glucagon

• Glucagon is secreted is response to– Hypoglycemia– Stress

• Hypoglycemia may occur during– Stress– Exercise– Fasting

Somatostatin

• A hormone secreted by the delta cells of the Islets of Langerhans

• Secreted in response to– Hyperglycemia

• Action– Interferes with glucagon– Interferes with growth hormone

Somatostatin

• Has a hypoglycemic effect

Diagnostic tests

• Blood glucose / Fasting blood glucose

• 2 hr PPG• Glucose tolerance Test• Glycosylated

Hemoglobin Assay

Blood Glucose Fasting blood Glucose

• Measures blood glucose levels after fasting

• Results– Normal – 70-115 mg/dL– Diabetic level > 126 mg/dL– Critical > 400 mg/dL – Critical < 50 mg/dL

Fasting Blood GlucoseNursing Responsibility

• Fast 6-8 hours• Water OK• No insulin or anti-diabetic meds• Exercise will effect results• Meds that interfere

2-hour post-prandial glucose

• Measure blood glucose 2 hours after a meal• Normal – 70-140 mg/dL

• Diabetic level – > 140 mg/dL

2-hour post-prandial glucoseNursing responsibility

• Eat entire meal• Don’t eat anything more until blood draw• Water OK• Notify lab when meal is finished• Exercise with effect results

Glucose Tolerance TestNursing responsibility

• Evaluates blood glucose and urine glucose– 30 minutes before– 1 hour after– 2 hours after– 3 hours after– 4 hours after

• A glucose load

Glucose Tolerance Test• Normal– Blood glucose < 140mg/dL at 2 hours– Urine negative for glucose (all times)

• Diabetic level– Blood glucose > 140 mg/dL at 2 hours– Glucose in urine

Glucose Tolerance TestNursing responsibility

• Fasting 6-8 hours before test• Hold meds that interfere• Administer glucose load• Water encouraged• Collect urine hourly• Administer meal and meds afterwards

Glycosylated Hemoglobin Assays (Hgb A1C)

• Percentage of glycosylated hemoglobin– RBC lifecycle • @ 120 days (4 months)

– Glucose slowly binds with Hgb glycosylated– serum glucose level glycosylated Hgb levels

Hgb A1C

• Provides an average blood glucose levels – Past 2-3 months

• Can be taken any time

• Normal levels (non-diabetic)– 4-6%

• Diabetic level (goal)– <8%

Small group questions

1. What is the difference between exocrine and endocrine glands?

2. Describe anatomically the location of the pancreas.

3. What are the Islets of Langerhans?4. Name the three hormones of the pancreas

and identify what cells secrete what hormone.

Small group questions

5. What stimulates each hormone to be secreted?6. What effect does insulin have on…

a. Glucoseb. Glycogenc. Protein metabolismd. Protein synthesise. Fat metabolismf. Fat synthesis