Hyposecretion and Hypersecretion

Halki Diabetes Remedy

Natural Diabetes Cure and Treatment

Get Instant Access

Inadequate hormone release is called hyposecretion. It can result from tumors or lesions that destroy an endocrine gland or interfere with its ability to receive signals from another gland. For example, a fractured sphenoid bone can sever the hypothalamo-hypophyseal tract and thus prevent the transport of oxytocin and antidi-uretic hormone to the posterior pituitary. The resulting ADH hyposecretion disables the water-conserving capability of the kidneys and leads to diabetes insipidus, a condition of chronic polyuria without glucose in the urine. (Insipidus means "without taste" and refers to the lack of sweetness of the glucose-free urine, in contrast to the sugary urine of diabetes mellitus.) Autoimmune diseases can also lead to hormone hyposecretion when misguided antibodies (autoantibodies) attack endocrine cells. This is thought to be one of the causes of diabetes mellitus, as explained shortly.

Excessive hormone release, called hypersecretion, has multiple causes. Some tumors result in the overgrowth of functional endocrine tissue. A pheochromocytoma (FEE-o-CRO-mo-sy-TOE-muh), for example, is a tumor of the adrenal medulla that secretes excessive amounts of epinephrine and norepinephrine (table 17.8). Some tumors in nonendocrine organs produce hormones. For example, some lung tumors secrete ACTH and thus over-stimulate cortisol secretion by the adrenal gland. While certain autoimmune disorders can cause endocrine hyposecretion, others cause hypersecretion. An example of this is toxic goiter (Graves25 disease), in which autoan-

25Robert James Graves (1796-1853), Irish physician

Saladin: Anatomy & I 17. The Endocrine System I Text I I © The McGraw-Hill

Physiology: The Unity of Companies, 2003 Form and Function, Third Edition

Chapter 17 The Endocrine System 667

Chapter 17 The Endocrine System 667

Same Person Different Ages Pictures
Figure 17.24 Acromegaly, a Condition Caused by Growth Hormone Hypersecretion in Adulthood. These are four photographs of the same person taken at different ages. Note the characteristic thickening of the face and hands. How would she have been affected if GH hypersecretion began at age 9?

tibodies mimic the effect of TSH on the thyroid, causing thyroid hypersecretion (table 17.8). Endocrine hypersecretion disorders can also be mimicked by excess or long-term clinical administration of hormones such as cortisol.

Following are brief descriptions of some of the better-known disorders of the major endocrine glands. Table 17.8 provides further details on some of these and lists some additional endocrine disorders. Diabetes mellitus, by far the most prevalent endocrine disease, receives a more extended discussion.

Was this article helpful?

+2 0
Delicious Diabetic Recipes

Delicious Diabetic Recipes

This brilliant guide will teach you how to cook all those delicious recipes for people who have diabetes.

Get My Free Ebook


Post a comment