Chapter 4

Endocrinology

Terms•Hormones

•Endocrine glands•Exocrine glands

•Homeostasis•Metabolism

•Automatic nervous system

Glands

8 Major Glands•Hypothalmus•Pituitary gland•Thyroid gland

•Parathyroid glands

•Thymus•Pancreas

•Adrenal Glands•Gonads

Hypothalamus

Hypothalmus

•Deep within cerebrum•Acts as a gland and as neurons

•Divided into sympathetic and parasympathetic nervous systems

•Affects posterior and anterior pituitary gland

Pituitary Gland

Pituitary

•The size of a pea•Posterior responds to nerves impulses

from hypothalmus•Anterior responds to hormones•Posterior Produces 2 hormones

–Antidiuretic hormone–Oxytocin

Anterior Pituitary

•Adrenocorticotropic Hormone (ACTH)•Thyroid Stimulating Hormone (TSH)•Follicle Stimulating Hormone (FSH)

•Luteinizing Hormone (LH)–Gonads

•Prolactin Hormone (PRL)•Growth Hormone (GH)

Thyroid Gland

•Thyroxine•Triiodothyronine

•Calcitonin

Disorders of the Thyroid Gland

•Hyperthyroidism•Thyrotoxicosis

•-long term exposure

•Hypothyroidism•Myxedema

•-long term exposure

Graves Disease

•Autoimmune disease•Too much thyroid hormones

•Agitation, weight loss, poor heat tolerance

•Protrusion of the eyeballs (exophtalmos)

A Grave Disease

Thyrotoxic Crisis

•“Thyroid Storm”•High fever

•Hypermetabolic state•Tachycardia

Hypothyroidism

•Low metabolic state•Hypothermic coma

•Myxedema Coma

Adrenal Glands

•Located on kidneys•Adrenal Medulla

•Adrenal Cortex

Adrenal Medulla

•Both nerve and gland cells•Sympathetic Nervous System

•Release of epinephrine and norepinephrine

Adrenal Cortex

•Secretes three steroids:•Glucocorticoids (including cortisol)

•Mineralocorticoids (including aldosterone)

•Adrogenic Hormones

Disorders of the Adrenal Glands

•Cushing’s syndrome- too much•Addison’s disease- not enough

Cushing’s Syndrome •Too much activity•Too much prednisone•Moon Faced•Buffalo Hump

Addison’s Disease

•Too little•Cortical destruction

•Autoimmune disease•May be due to steroid use

•Weakness, fatigue, decreased appetite•Low blood glucose

•Hyperkalemia

Pineal Gland

•Melatonin•Located in the thalmus of the brain

Pancreas•Three types of

cells:–Alpha (α)

–Beta (β)–Delta (δ)

•Alpha Cells – Glucagon•Beta Cells – Insulin

•Delta Cells – Somatostatin

Disorders of the Pancreas•Diabetes Mellitus

–Glucose Metabolism

Glucagon

•Antithesis of Insulin•Stimulates breakdown of glycogen to

Glucose•GLYCOGENOLYSIS•Glycogen is stored throughout the

body, but most prevalent in the LIVER

•Fasting blood glucose 80-90 mg/dL

Fueling the Body

•Fuel of Choice – Glucose•Secondary Fuel – Stored Fat

Scuba Divers and Marshmellows

•Glucose = Marshmellows•Insulin=Scuba Divers

Normal Metabolism

•Glucose is needed for cellular metabolism•Glucose freely crosses the blood / brain

barrier•In other parts of the body, insulin is needed

for passage of glucose into cells

Diabetes

•Type 1•Type 2

–Insulin Dependant–Noninsulin Dependant

Type I Diabetes

•Juvenile•Closely related to heredity

•IDDM•Low production of insulin

Signs and Symptoms of Diabetes

•Weakness•Polyuria

•Weight loss•Ketosis

•Diabetic Ketoacidosis

Diabetic Emergencies

Diabetic Emergencies•Diabetic Ketoacidosis

–Pathophysiology•Results from the body’s change to fat metabolism•Continuous buildup of ketones produces significant

acidosis–Signs and Symptoms

•Extended period of onset (12–24 hours)•Sweet, fruity breath odor

•Potassium-related cardiac dysrhythmias•Kussmaul’s respiration

•Decline in mental status and coma

Increased Respiratory Effort

•Body’s mechanism to compensate for decreased pH

•Breakdown of fatty stores results in production of ketones

Diabetic Emergencies•Hyperglycemic Hyperosmolar Nonketotic

Coma (HHNC) –Pathophysiology

•Found in Type II diabetics•Results in blood glucose levels up to 1000mg/dL

•Insulin activity prevents buildup of ketones•Sustained hyperglycemia results in marked dehydration

–Often related to dialysis, infection, and medications•Very high mortality rate

Diabetic Emergencies

•Hypoglycemia (Insulin Shock)

•Treatment–Oral Glucose

–Dextrose–Glucagon