The Endocrine System l With nervous system coordinates the function of all body systems l Regulates homeostasis through hormones

Hormones l Over 50 hormones l Secretions enter blood l Effect target cell, tissue organ l Most only affect a few types of cells

FUNCTIONS OF HORMONES l Helps regulate: l 1. metabolism l 2. ICF & ECF balance l 3. contraction of smooth and cardiac muscle l 4. Reproductive system l Control growth & development

Hormone Function

Pituitary Gland

Thyroid

Parathyroid

Adrenal glands

Pancreas l The endocrine tissue of the pancreas is called the Pancreatic Islets or Islets of Langerhans l Alpha Cells - secrete Glucagon –raises blood sugar l Beta Cells - secrete Insulin –lowers blood sugar

STRESS l Anything that disrupts homeostasis l May be physical l May be related to life situations

General Adaptation syndrome (GAS) l Three stages l Body’s response to stress

Alarm Stage l Body is preparing for stress l Body’s way of dealing with a stressor

Body changes during alarm l Increase blood pressure l Increase heart rate l Muscles tense l Decrease in blood supply to digestive system

Body changes during alarm l More mentally alert l Better hearing and eyesight l Sweating l Dry mouth l More blood and glucose to muscles

Resistance stage l Body is dealing with the stress l Body is trying to keep going l Body’s way of dealing with prolonged stress

Exhaustion stage l Body is worn out l Major fatigue l Increase in cortisol levels l Decrease in K+ l Immune system is depressed l Illness may occur

Metabolic Diseases and Disorders of the Endocrine System

Dwarfism l caused by a hyposecretion of hGH during the growth years –causes slow bone growth –epiphyseal plates close before normal height is reached –other organs of the body may also fail to grow and develop l treatment requires administration of hGH during childhood

Gigantism l caused by the hypersecretion of hGH during childhood –abnormal increase in bone length and size of other organs l the person is very tall with normal body proportions

Acromegaly l caused by the hypersecretion of hGH during adulthood l also caused by steroid and hGH use –bones of hands, feet, and skull thicken –eyelids, lips, and tongue enlarge –skin thickens and develops furrows

Cushing’s Syndrome l caused by hypersecretion of glucocorticoids, especially cortisol l results in redistribution of body fat –spindly arms and legs –rounded moon - faced appearance –hanging abdomen with stretch marks or Striae l individuals often bruises easily l poor wound healing

Cretinism l caused by hyposecretion of thyroid hormones during fetal development –exhibits dwarfism because the skeleton fails to grow –individuals are usually severely mentally retarded –retarded sexual development –usually have a yellowish skin color

Myxedema l caused by hypothyroidism during the adult years l causes facial tissue to swell and look puffy l about 5 times more common in females l other symptoms include: –bradycardia- low body temperature –lethargy- muscle weakness –dry skin and hair- easily gains weight –sensitivity to cold- hypersensitive to drugs

Graves’ Disease l caused by hyperthyroidism l an autoimmune disorder –increased metabolism- heat intolerance –increased sweating- insomnia –weight loss- nervousness –tremors of hands l may have a slightly enlarged thyroid gland (Goiter) l causes the eyes to protrude (Exophthalmos)

Diabetes Mellitus l a group of disorders that leads to an elevation of blood glucose (Hyperglycemia) l symptoms include: –polyuria- polydipsia –polyphagia- glucosuria l Two Types or Categories of Diabetes –Type I Diabetes = Insulin Dependent Diabetes Mellitus (IDDM) –Type II Diabetes = Non Insulin Dependent Diabetes Mellitus (NIDDM)

Type I Diabetes (IDDM) l pancreas does not produce insulin due to the destruction of Beta cells in the Islets of Langerhans l requires regular injections of insulin to prevent death l most commonly develops in individuals younger than 20 years old (Juvenile Onset Diabetes Mellitus) l appears to be an autoimmune disorder

Type II Diabetes (NIDDM) l also called Maturity Onset Diabetes l much more common type of Diabetes (over 90% of Diabetes cases) l most often occurs in individuals over 40 l most individuals are overweight or clinically obese l blood glucose levels can usually be controlled by diet, exercise, and weight loss and control

Complications from Diabetes l atherosclerosis l heart disease l peripheral vascular disease l severe kidney damage l glaucoma l gangrene l ketoacidosis l weight loss

Treatments for Diabetes l regular insulin injections l artificial pancreas l transplantation of the pancreas l transplantation of clusters of Islet Cells l injection of fetal Islet Cells