2-4.
DISEASES OF THE PITUITARY GLAND--ANTERIOR LOBE
a. Hypersecretion (Hyperpituitarism, Acromegaly, Gigantism).
(1) Description. The pituitary gland secretes too much of the growth
hormone. If this occurs in children, the result is giantism (an abnormal skeletal
development). Excessive production of the growth hormone when an individual is an
adult causes acromegaly (head, face, hands, feet, and internal organs get progressively
larger). In giantism, the people are generally large but usually very weak. In
acromegaly, the bones of the face, hands, and feet widen. The jaw protrudes, and the
forehead bones bulge.
(2) Signs and symptoms. The condition acromegaly develops slowly and
produces a variety of symptoms including excessive sweating, oily skin, a high
metabolic rate, and heavy hair growth in places where the hair growth is usually light;
for example, on the female face. In contrast, giantism seems to develop rapidly. As
giantism progresses, the pituitary tumor which causes the condition gets bigger causing
disturbances in other systems of the body. Treatment includes irradiation or surgical
removal of the tumor.
b. Hyposecretion.
(1) Description. The condition occurs when not enough hormones are
secreted by the anterior lobe of the pituitary gland. The result is metabolic dysfunction,
sexual immaturity, and growth retardation when the problem takes place in childhood.
In an adult, insufficient amounts of these hormones results in a condition called
Simmond's disease. Signs and symptoms include emaciation (extreme thinness),
asthenia (severe weakness or loss of strength), lowered metabolic rate, low
temperature, and low blood pressure. The cause of this deficiency in the production of
hormones is usually trauma, tumor, or hemorrhage.
(2) Treatment. Treatment is either surgical removal or x-ray irradiation if
there is a tumor. Drug therapy to replace needed hormones is very effective. Cortisol,
thyroxin, and androgen or cyclic estrogen may be prescribed.
2-5.
DISEASES OF THE PARATHYROID GLANDS
a. Hyperparathyroidism. One or more of the parathyroid glands enlarges. Too
much parathyroid hormone is secreted, and the serum calcium level becomes too high.
There is a change in the function of cells of the bone, renal tubules, and gastrointestinal
mucosa. The withdrawal of calcium from bones (osteoporosis) leads to hypercalcemia
(abnormally high concentration of calcium in the blood) and kidney stones. Other signs
and symptoms include muscular weakness, gastrointestinal symptoms such as
anorexia, nausea, vomiting, and abdominal pains. Treatment depends on the diagnosis
of the cause of the condition. Surgical removal of the parathyroid tissue is often the
treatment.
MD0583
2-8