Chemical Coordination and Integration

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Thyroxin (tetraiodothyronine, T4 ) & Triiodothyronine (T3)

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Thyrocalcitonin (TCT): A protein hormone. It regulates (lowers) the

blood calcium levels. Iodine is essential for normal hormone synthesis

in thyroid.

Their functions are:

Regulation of

basal metabolic

rate (BMR)

Physical, mental

and sexual

development

Support RBC

formation

Control

metabolism of

carbohydrates,

proteins & fats.

Maintain water

and electrolyte

balance.

HÝPØTHÝRØÏDÏSM (GØÏTRË)

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Enlargement of thyroid gland due to deficiency of iodine.

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In adult women, it causes irregular menstrual cycle.

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Hypothyroidism during pregnancy affects the baby causing stunted

growth (cretinism), mental retardation, low intelligence quotient,

abnormal skin, deaf-mutism etc. (NEET 2013)

HÝPËRTHÝRØÏDÏSM

Abnormal increase of thyroid hormones resulting

in adverse effects on the physiological activities.

1

2

It is caused due to development of the nodules or

the cancer of thyroid gland.