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 = 2 nd 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 of Glucose by the liver What “G” word means the release of glucose by the liver? A.Glycogen B.Glycogenesis C.Glycogenolysis D.Glucose E.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 – mg/dL – Diabetic level > 126 mg/dL – Critical > 400 mg/dL – Critical < 50 mg/dL

Fasting Blood Glucose Nursing 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 – mg/dL Diabetic level – > 140 mg/dL

2-hour post-prandial glucose Nursing 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 Test Nursing 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 Test Nursing 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 120 days (4 months) – Glucose slowly binds with Hgb  glycosylated –  serum glucose level   glycosylated Hgb levels

Hgb A 1 C 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.Glucose b.Glycogen c.Protein metabolism d.Protein synthesis e.Fat metabolism f.Fat synthesis