Let us learn about the Disorders of Pituitary Hormones.
(A) Due to hyper secretion of STH:
(a) Gigantism:
This disease is caused by hyper secretion of STH in child. It is characterized by morphological, physiological, psychological and sexological features (Fig. 12.1).
(i) Morphological features:
1. Abnormal body height (7 to 8 ft.)
2. Unusual elongation of limbs and hands.
3. Thickening of skin of eyelids and nose.
4. Thick lips.
5. Well-built muscle.
6. Visceral organs enlarged.
7. Face looks like young individual,
(ii) Physiological features:
1. Excess sweating.
2. May cause glycosuria.
3. Less Ca++ in blood.
4. Increased BMR.
(iii) Psychological features:
Individual becomes intelligent.
(iv) Sexological features:
1. The primary and secondary sex characters are not well developed.
2. The sexual activity may be decreased.
(b) Acromegaly:
This disease is caused by the hyper secretion of STH in adult condition due to tumors of somatotrophs. It is characterized by
(i) Morphological features (Fig. 12.2)
1. There is overgrowth of the membranous bones like skull, upper jaw, lower jaw.
2. Protrusion of lower jaw (Prognathism).
3. The acral parts like small bones of hands and feet become grossly enlarged and become spade like.
4. Irregular enlargement of hands and feet.
5. Abnormal increase of facial length.
6. Thickening of skin of fingers, hands, feet, nose, lips etc.
7. Body bends in form due to abnormal growth of vertebral column.
8. Eye brow ridges become prominent.
9. Increase of visceral organs like heart, liver and lung.
10. The size of thyroid and adrenal glands become enlarged.
11. The tongue is enlarged.
(ii) Physiological features:
1. May cause hyper-glycaemia.
2. Less Ca++ in the body.
3. Increased BMR.
4. Increased secretion of sweat.
(iii) Psychological features:
1. Mental disturbances.
2. Not so intelligent.
(iv) Sexological features:
1. Sexual function in both become depressed.
2. Gonads become reduced in size.
3. In male, there is loss of libido effect.
4. In female, menstrual disturbances and ill developed breast takes place.
(B) Due to Hypo-secretion of STH:
(a) Dwarfism:
It is caused due to hypo-activity of STH cells in pre-pubertal life.
It shows following features:
(i) Morphological features (Fig. 12.3)
1. Very abnormal short height (about 3 ft.)
2. Abnormal skeletal growth.
3. The body proportions and facial features of an adult looks like a normal child.
4. Skin becomes smooth.
5. Primary teeth appear at the expected age but the eruption of secondary teeth is delayed.
6. Round face.
(ii) Physiological features:
1. BMR is low.
2. Loss Ca++ in blood.
3. Hypoglycaemia occurs.
4. The insulin response to glucose in usually subnormal.
5. Accumulation of nitrogen product is increased.
(iii) Psychological features:
1. Normal intelligence is developed in proportion to age.
2. Psychological adjustment becomes difficult when they enter into adult stage.
(iv) Sexological features:
1. Gonads are underdeveloped.
2. Secondary sex characters are less developed.
3. Loss of sexual desire in adult.
Type of Dwarfism:
(a) GH-deficiency dwarfism:
It is characterised by failure of STH secretion and a consequent decline in IGF-I (insulin like growth factor-l) formation.
(b) Laron-type dwarfism:
It is characterised by the deficiency on defect of hepatic STH receptors so that plasma IGF-I is low in-spite of a high plasma level of STH.
(c) Pigmy type dwarfism:
It is characterised by the defect in synthesis of IGF-I.
(d) Forlich’s type dwarfism:
It is caused due to damage of tissues of adenohypophysis.
(b) Acromicria:
It is caused due to hypo-secretion in adult. It is characterized by following features.
(i) Morphological features:
1. Retarded development of bones, feet and face.
2. Some ridge formation takes place on the bones of face.
3. Loss of hairs.
4. Skin is wrinkle and dry.
5. Adiposity is fairly common.
(ii) Physiological features:
1. Low BMR.
2. Less Ca++ level in blood.
3. Accumulation of nitrogenous products.
4. Polyuria.
(iii) Psychological features:
1. Mentally backward.
2. Idiotic behaviour.
(iv) Sexological features:
1. Gonads are reduced.
2. Sexual functions are reduced.
(C) Due to Hypo Secretion of Vasopressin/ADH:
Diabetes incipidus:
This disease is caused by severe depression or suppression of neurohypophysial hormone vasopressin (ADH) secretion. It is of two types—(i) neurogenic and (ii) nephrogenic.
(i) Neurogenic type:
Due to damage of hypathalamo-hypophysial system, or development of hypothalamic tumour, or damage of nervous system, or infections etc.
(ii) Nephrogenic type:
Due to unresponsiveness of renal tissue to vasopressin or renal infections, or renal defects.
Symptoms:
(i) Polyuria (production of large volume of urine)
(ii) Poly dypsia (severe thirst)
(iii) Hypokalemia (electrolyte disorder)
(iv) Physical and mental retardation.
(v) Dilation of urinary bladder.
Special notes:
A. Hormone deficiency:
(A) Hypopituitarism:
It is caused by the hypo-function of anterior pituitary. The main etiology of this is formation of tumor, pituitary apoplexy, head trauma, radiation therapy, surgery problems etc. (Figs. 12.4 and 12.5).
(B) Hyperpituitarism:
Hyperactivity of adenohypophysis occurs due to formation of neoplastic pituitary tumour, hypertrophy or enhanced hypothalamic stimulation.
(C) Pan hypopituitarism:
It involves total loss of hypophysial hormone secretion which could be due to a congenital dysfunction, i.e., failure of the pituitary to develop, or to destruction of the pituitary at a later stage in life. It is also possible that the pars distalis might fail to secrete only one of its many hormones.
(D) Hyperprolactinemia:
This disease is formed by hyper secretion of prolactin (LTH). Hyper secretion takes place due to pituitary adenomas or defect in hypothalamohypophysial system. In case of pituitary adenoma, lateral growth of adenohypophysis takes place.
Symptoms:
1. Weight gain.
2. Nervousness and irritability.
3. Visual impairment.
4. Coloured patches appear in the body.
5. In male, breast development occurs.
6. In women, irregular menstruation.
7. Fertility becomes reduced and may cause impotency.
8. Decreased libido effect.
9. Milky fluid secretion takes place from mammary gland.
10. Hirsutism occurs.
11. In female, amenorrhea, galactorrhea and oligomenorrhea occur.