Endocrine Disorders: Types, Causes, and Consequences, Study notes of Pathophysiology

Download Endocrine Disorders: Types, Causes, and Consequences and more Study notes Pathophysiology in PDF only on Docsity! 1 Endocrine Disorders Bio 375 Pathophysiology Endocrine Disorders Two categories of endocrine disorders Excessive production of hormone Deficient production of hormone Manifestations of hormonal disorders reflect the actions of the hormone May alter appearance of the individual Disorder beginning in children Disorder beginning in adult May alter metabolism of the individual Most common cause of endocrine disorders is benign tumor or adenoma Adenoma may be secretory producing excess hormone Adenoma may be destruction causing a hormonal deficit Target cells may be resistant or insensitive to the hormone creating the effect of a deficit (e.g. Type II Diabetes mellitus) 2 Other causes of hormonal problems: Congenital defects in the glands Hyperplasia of the glands Infection of the glands Abnormal immune reactions Vascular problems Ectopic sources of hormones, e.g bronchogenic (lung) cancer produces PTH or ACTH Negative Feedback Mechanism with Glucose and Insulin and Glucagon Insulin and Diabetes Mellitus Common chronic disorder Major factor predisposing to: Strokes (CVA) Heart attacks (MI) Peripheral vascular disease Amputation Kidney failure Blindness 5 Questions 1-3 Type II Diabetes Mellitus About 90% of cases of Diabetes Mellitus Age of onset: 40-70 yr Insidious onset Genetic susceptibility exacerbated by long- duration obesity Insulin resistance not clearly understood Insulin levels are typically high at diagnosis but decline over the course of the illness Treatment consists of dietary control, exercise and sometimes medication USA Today 4/10/2007 6 Symptomatic Results of Insulin Deficit (Diabetes mellitus) Exercise and Diabetes mellitus While exercise can be useful in controlling glucose levels in diabetes, excessive and prolonged exercise can precipitously deplete glucose levels resulting in hypoglycemia or hypoglycemic shock (insulin shock) Excessive insulin can also cause hypoglycemic shock Insulin shock can result in coma or death 7 10 Parathyroid Hormone Control Parathyroid Hormone Hypoparathyroidism leads to hypocalcemia or low serum calcium levels Hypocalcemia affects nerve and muscle function in several ways Weak cardiac muscle contractions Increase in the excitability of nerves leading to spontaneous contraction (tetany) of skeletal muscle Hyperparathyroidism causes hypercalcemia or high serum calcium levels Hypercalcemia leads to forceful cardiac contractions Increased PTH concentrations cause demineralization of osseus tissue leading to osteoporosis It also predisposes to kidney stones 11 Immobility may lead to hypercalcemia along with low PTH Severe kidney disease results in hyperphosphatemia, hypocalcemia and high serum PTH 12 Pituitary Hormones Benign adenomas are the most common cause of pituitary disorders About 10% of intracranial tumors Occur primarily in persons aged 30-50 Two types of signs in patient Effect of the mass as it causes increased intracranial pressure Effect of tumor on hormonal secretions Growth Hormone Dwarfism or short stature Deficit of GH or GH-RH Adenoma may affect more than one cell type causing multiple deficits Pituitary dwarfs usually have: Normal intelligence Normal body proportions Some delay in skeletal maturation and puberty Gigantism or tall stature Excess of GH prior to puberty Acromegaly refers to the effects of excess of GH in the adult, usually by an adenoma Bones become broader and heavier, skull thickens, jaw enlarges and facial features coarsen Soft tissues grow, resulting in enlarged hands and feet, tongue protrudes 15 Goiter Goiter refers to an enlargement of the thyroid gland May be caused by hyper- or hypothyroid conditions Can be large and can interfere with shallowing, breathing and be of cosmetic concern Endemic goiter due to dietary deficiency of I2 Goitrogens inhibit T3 and T4 and elevate TSH causing goiter formation Toxic goiter Hyperthyroidism (Graves Disease) Occurs more frequently in women over age 30 Autoimmune disease Hypermetabolism Toxic goiter Exophthalmos Increased sympathetic activity magnifies metabolic effects 16 Hypothyroidism Mild hypothyroidism is common and easily treated Severe hypothyroidism Hashimoto’s thyroiditis Myxedema Cretinism Adrenal Cortex Cushing’s Syndrome due to excessive glucocorticoids Pituitary tumor (75-80%) Adrenal tumor Ectopic carcinoma (paraneoplastic syndrome) Iatrogenic conditions from administration of large amounts of glucocorticoids for chronic inflammatory conditions Changes in persons appearance Obesity with moon face Sodium and water retention Heavy trunk Fatty hump on neck (buffalo hump) Muscle wasting in limbs Fragile skin Osteoporosis Immune suppression with increased infections Decreased stress response Changes in mental status; including irritability, clinical depression and schizophrenia. = Questions 9-10 17