Endocrine System

Word partsAcr/o: extremitiesCalc/o: calciumChrom/o: colorPhys/o: air, gasToxic/o: poisonAdrenal/o, adren/o: adrenal glandGluc/o, glyc/o: sugar, sweetnessParathyroid/o: parathyroid glandPituitar/o: pituitary glandSphen/o: wedge, sphenoid boneThym/o: thymus glandThyr/o, thyroid/o: thyroid glandPhe/o: dusky, darkPan-: all

Overview • Endocrinologist: a medical doctor that deals with

disease of the endocrine system • Endocrinology: the branch of medicine concerned

with hormone imbalances• Parts: ducts, glands, hormones• Functions: to regulate various body functions and

keep the internal environment of the body stable • Regulates mood, controls metabolism and growth

and development• Influences sexual and reproductive functions

Overview Homeostasis: the ability of the body to maintain a stable internal environmentHormone: a chemical substance produced by the body that affects growth and development, sexual function, mood, metabolism and many other processesMetabolism: the sum of all chemical and physical processes occurring within living cells

Diseases and Conditions • Addison disease: decreased function of the adrenal

gland that results in muscle weakness and atrophy, loss of fluids and electrolytes, low blood pressure, hypoglycemia and hyperpigmentation of the skin• Cushing syndrome: excessive cortisol hormones

due to tumors or medications• Blood-glucose balances

Diseases and Conditions • Diabetes Mellitus: a group of diseases

characterized by high blood-glucose levels due to defects in insulin secretion, insulin action or both • Type 1: childhood diabetes with abrupt onset

caused by destruction of pancreatic cells and insufficient insulin absorption• Type 2: adult diabetes with gradual onset caused

by lowered insulin production

Diseases and Conditions • Insulinoma: a tumor of pancreatic cells• Pancreatitis: inflammation of the pancreas when

pancreatic enzymes that digest food are activated in the pancreas instead of the duodenum• Panhypopituitarism: total pituitary impairment

that causes loss of hormone activity• Pheochromocytoma: a rare adrenal gland tumor

that causes excessive release of epinephrine (adrenaline) and norepinephrine (hormone that regulate heartrate and blood pressure)

Diseases and Conditions • Hypothyroidism: thyroid hormone deficiency that

is the result of a developmental problem, injury, disease or dietary deficiency • Cretinism: hypothyroidism in infants• Can lead to mental retardation, growth impairment, low

body temperature and abnormal bone formation

• Myxedema: hypothyroidism in adults• Characterized by edema, weight gain, cold intolerance,

fatigue, depression, and muscle and joint pain

Diseases and Conditions • Hyperthyroidism: excessive secretion of thyroid

hormones resulting from a developmental problem, injury, disease or dietary deficiency • Graves disease: an autoimmune disease that

causes goiters (enlarged thyroid gland), exophthalmos (bulging eyes) elevated metabolic rate, weight loss, excessive perspiration, muscle weakness and emotional instability

Diseases and Conditions • Hypopituitarism: a deficiency of growth hormone

resulting in a short stature with normal body proportions “pituitary dwarfism”• Gigantism: excessive secretion of growth hormone

in children causing an abnormal increase in the length of long bones• Acromegaly: excessive secretion of growth

hormone in adults causing the overgrowth of bones in the face, hands and feet

Diagnostic Procedures • Fasting blood glucose: measures blood glucose

after the patient fasts for 8 hours• Glucose tolerance test: the patient fasts for 8-12

hours then ingests glucose and blood samples are taken to measure the metabolic rate of glucose• Radioactive iodine uptake test: determines thyroid

function by monitoring the ability of the thyroid to metabolize iodine

Diagnostic Procedures

• Thyroid function test: a blood test that measures thyroid hormone levels • Total calcium: a blood test that measures calcium

to detect parathyroid and bone disorders

Medical and Surgical Procedures• Lobectomy: removal of one lobe of the thyroid

gland in treatment of endocrine diseases• Thymectomy: excision of the thymus gland • Transsphenoidal hypophysectomy: endoscopic

surgery that removes pituitary tumors through the nasal cavity via the sinus without affecting the brain

Pharmacology

• Insulins: replace insulin in patients with diabetes• Oral antidiabetics: treat type 2 diabetes by

stimulating the pancreas to produce insulin or they lower blood glucose levels

Abbreviations

• ADH: antidiuretic hormone• BS: blood sugar• DM: diabetes mellitus• FBG: fasting blood glucose• FBS: fasting blood sugar• GH: growth hormone

Abbreviations

• GTT: glucose tolerance test• HRT: hormone replacement therapy• IV: intravenously• RAIU: radioactive iodine uptake• TFT: thyroid function test• TSH: thyroid-stimulating hormone