THE THYROID GLAND
The thyroid gland is located in the front of the neck, below the larynx. It consists of two lobes, one on each side of the windpipe, connected by tissue called the isthmus.
The thyroid is composed of several epithelial cells called thyroid follicles. Follicles are filled with colloid, a thyroid hormone precursor. Iodine is essential in order for the thyroid to produce the hormones.
HORMONES OF THE THYROID GLAND.
The thyroid gland produces 3 hormones when stimulated by TSH.
-
Thyroxine (T4) & Triiodothyronine (T3)
-
Calcitonin
FUNCTIONS OF THYROID GLAND
Thyroxine
Increase basal metabolic rate by stimulating cellular oxygen use to produce ATP; regulate metabolism.
Calcitonin
The functions of calcitonin is to regulate the amount of calcium and phosphte in the blood/body
DEFICIENCY OF THYROXINE
Goiter
Thyroid requires iodine to produce these hormones. A deficiency of iodine causes the enlargement of the neck region called goiter.
Cretinism
It also results into a condition called Cretinism. Cretinism results from abnormal thyroid development.
Features of cretinism
- Short
- stocky body type
- Severe hypothyroidism
- Mental retardation.
Myxedema
Myxedema is hypothyroidism in adults-
Features of cretinism
- Lethargy
- Weight gain
- Loss of hair
Grave’s disease
Grave’s disease is caused as the result of hyperthyroidism. The condition causes:
- Exophthalmic goiter
- Edema behind eyes, causing them to bulge Hyperactivity
- Arrythmias
| Antidereutic | Parathyroid |