Pituitary

A pituitary adenoma (tumor) usually increases secretion of growth hormone or ACTH. Less commonly, a tumor affects the secretion of prolactin. An excess of growth hormone in children causes gigantism. In

DISPLAY 16-2 Disorders Associated With Endocrine Dysfunction*

HORMONE

HYPERSECRETION

HYPOSECRETION

growth hormone

gigantism (children), acromegaly (adults)

dwarfism (children)

antidiuretic hormone

syndrome of inappropriate ADH (SIADH)

diabetes insipidus

aldosterone

aldosteronism

Addison disease

cortisol

Cushing syndrome

Addison disease

thyroid hormone

Graves disease, thyrotoxicosis

congenital hypothyroidism (children), myxedema (adults)

insulin

hypoglycemia

diabetes mellitus

parathyroid hormone

bone degeneration

tetany (muscle spasms)

*Refer to key terms for pronunciations and descriptions.

adults it causes acromegaly, characterized by enlargement of the hands, feet, jaw, and facial features. Treatment is by surgery to remove the tumor (adenomectomy) or by drugs to reduce the level of growth hormone in the blood. Excess ACTH overstimulates the adrenal cortex, resulting in Cushing disease. Increased prolactin causes milk secretion, or galactorrhea, in both males and females. Radiographic studies in cases of pituitary adenoma usually show enlargement of the bony structure in the skull (sella turcica) that contains the pituitary.

Hypofunction of the pituitary, such as is caused by tumor or interruption of blood supply to the gland, may involve a single hormone but usually affects all functions and is referred to as panhypopituitarism. The widespread effects of this condition include dwarfism (from lack of growth hormone), lack of sexual development and sexual function, fatigue, and weakness.

A specific lack of ADH from the posterior pituitary results in diabetes insipidus, in which the kidneys have a decreased ability to conserve water. Symptoms are polyuria (elimination of large amounts of urine) and polydipsia (excessive thirst). Diabetes insipidus should not be confused with diabetes mellitus, a disorder of glucose metabolism described below. The two diseases share the symptoms of polyuria and polydipsia but have entirely different causes. Diabetes mellitus is the more common disorder, and when the term diabetes is used alone, it generally refers to diabetes mellitus. The word diabetes is from the Greek meaning "siphon," referring to the large urinary output in both forms of diabetes.

Diabetes Sustenance

Diabetes Sustenance

Get All The Support And Guidance You Need To Be A Success At Dealing With Diabetes The Healthy Way. This Book Is One Of The Most Valuable Resources In The World When It Comes To Learning How Nutritional Supplements Can Control Sugar Levels.

Get My Free Ebook


Post a comment