Function
Your windpipe is straddled by the two lobes of your thyroid gland. Using two hormones, triiodothyronine and thyroxine, your thyroid regulates various enzymes that dominate energy metabolism. Calcitonin, a blood calcium lowering hormone, is also released by the thyroid. Thyrotrophin from the anterior pituitary keeps thyroid hormones in check.

Snuggled in the thyroid's under belly are four tiny parathyroid glands that emit parathormone. PTH acts on your gut, bones and kidneys to control phosphate and calcium metabolism. Without this regulation, bone and nerves suffer. Too little PTH and a convulsive, twitching condition called tetany ensues. Too much PTH leads to high blood calcium and eventually a bone softening disease called osteitis fibrosa cystica.

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When thyroid hormones are deficient, hypothyroidism manifests. Because energy control is pivotal to thyroid function, hypothyroidism is a condition of reduced energy--you feel tired and cold, become constipated, have less appetite but gain weight, feel sleepy. Even your thoughts are sluggish.

The first way to combat low thyroid hormones is by avoiding goitrogenic foods like soybeans, peanuts, millet, turnips, cabbage and mustard. These foods block the thyroid from using iodine, an element vital for thyroid hormone production. Zinc, vitamin E and vitamin A are also central to thyroid hormone synthesis.

Function
Squeezed behind your breast bone and just below the thyroid is an irregularly shaped member of both the endocrine and immune systems--the thymus. Relatively large in childhood, the thymus grows until the teen years, then shrinks with age. Fat replaces active lymphatic tissue.

Thymosin, thymopoeitin and serum thymic factor--thymus hormones--oversee several immune operations. Before and shortly after birth, a baby's thymus gland preprocesses T-lymphocytes, the white blood cells in charge of cellular immunity. This type of immunity, the kind not controlled by antibodies, shields your body from yeast, fungi, parasites, viruses, cancer and allergies. Thymopoeitein also activates circulating T-cells.

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Because the thymus shrivels with age, its importance has been downplayed. Stress, pollution, chronic illness, radiation and AIDS also diminish thymus function. However, low thymic hormone levels are associated with depressed immunity and elevated infection susceptibility. A cardinal symptom of infection is fatigue.

An ideal way to protect your thymus gland is to use antioxidant nutrients like beta-carotene, zinc, selenium, vitamins C and E. A high potency multi vitamin-mineral supplement is a good way to accomplish this. Thymus gland extracts, derived from calf thymus, is another effective way to stimulate your thymus gland. Echinacea angustifolia, a famous immune-stimulating herb, may also work via the thymus gland. At least one Japanese shows licorice, Glycyrrhiza glabra, to have direct thymic effects (Endocrinology Japan, 1967, vol 14).

Function
Perched atop each kidney is a triangular shaped adrenal gland. The adrenals are divided into two distinct parts somewhat like a peach. The outer fleshy fruit of a peach is like the cortex or outer region of the adrenal, while the pit resembles the smaller inner medulla of the adrenal gland. All adrenal hormones are ruled by adrenocorticotrophic hormone (ACTH) from the anterior pituitary.