Nutrition and Metabolism Negative Feedback System Pancreas: Hormones in Balance Insulin & Glucagon Hormones that affect the level of sugar in the blood

A. Meal is eaten …… food is converted to glucose B. Intestines absorb the glucose C. Glucose enters the bloodstream; Blood glucose levels rise D. Pancreas produces insulin E. Liver & other tissue cells take in glucose F. Blood sugar level drops and pancreas stops secreting insulin How Food is digested

When Blood Sugar Levels Decrease: Hungry or Starving And the body needs glucose Glucagon is released by the pancreas & Stimulates the conversion of glycogen in the liver to glucose raises the level of glucose (sugar) in the blood

Insulin is the only hormone that Decreases Blood Sugar Levels Help glucose across the plasma membrane Once inside the cell, glucose is oxidized for energy OR Converted to glycogen (in the liver) or fat for storage Blood sugar (glucose) levels will FALL and Insulin release ends

The pancreas should produce enough insulin for the body Insulin stimulates cells to use glucose protein, fats, and carbohydrates will be broken down into usable glucose or converted to stored glycogen in the liver Or synthesize lipids

Negative-Feedback Totally responding to blood glucose Either insulin or glucagon are working in this cycle of hormones Another one involved: Somatostatin may regulate the secretion of glucagons and insulin

Making food usable Intestine absorbs it Insulin is released Liver converts it to glycogen

Glucagon - Hormone of metabolism When the body needs glucose glucagon converts amino acids & breaks down lipids in the liver - to make glucose available Stored glycogen in the liver is converted into usable glucose in the bloodstream Main Target is the Liver

Pancreas releases either glucagon or insulin into the blood stream Has high blood Sugar -Releases Insulin Needs glucose Has not eaten recently Releases glucagon OR

Cellular Metabolism & Respiration Series of chemical reactions that happen in every cell of living organisms. glucose + oxygen carbon dioxide + water C 6 H 12 O 6 + O 2 CO 2 + H 2 0 The reactions release energy. Oxidation reactions because they remove electrons & add them to the oxygen in water.

CO 2 +H 2 O released No O 2 required O 2 required Lot of ATP released No O 2 required

Cellular Respiration Three Processes Glycolysis Takes place in the cytoplasm Releases small amounts of ATP Does not require oxygen. Krebs Cycle Takes place in the mitochondria Uses products from glycolysis Produces a small amount of ATP Produces CO 2 and H 2 O Electron Transport Chain. Takes place in the mitochondria Releases the majority of ATP

Electron Transport Chain

Specific pancreatic cells make Insulin Glucagon 75% of Beta cells make insulin 25% Alpha cells make glucagon

Glucose Levels are tightly regulated Normal levels are 70 to 125 mg /dL (random sampling - not “fasting”) Hypoglycemia > Low blood sugar Hyperglycemia > High blood sugar

Insulin controls blood sugar Insulin binds to receptors on the cell membranes and activates them. This activates metabolism inside the cell which allows the uptake, utilization and storage of glucose. Lack of insulin results in an increase in blood glucose concentration

Insulin Effects Insulin stimulates the liver to convert glucose to glycogen for short term storage. Insulin promotes to conversion of glycogen to fats for long term storage. Insulin inhibits the breakdown of fats. Insulin stimulates the uptake of amino acids.

Diabetes Mellitus- Type 1 Insulin insufficiency Pancreas doesn’t produce enough Requires insulin replacement therapy. Requires monitoring blood sugar, and matching your insulin supply with carbohydrate intake and exercise. Insulin must be injected.

Diabetes mellitus Type 2 Cells become resistant to insulin. Adult onset Insulin is ineffective- must be controlled by diet and exercise.

Consequences of Diabetes Poor circulation because the arteries become thicker and less elastic. Sores on the limbs that heal poorly Foot damage Higher cholesterol and triglyceride levels Eye damage Dementia Tooth and gum problems Heart Disease

Skin Ulcer in a Diabetic Food Poor Circulation Loss of feeling Neuropathy

Ulceration and Infection

Planned Amputation

Before & After Type I or Type II Either can lead to Poor circulation & Neuropathy

Ingrown Toenails Foot Care Skill: Cut with a round Cut