Question

Describe and explain the effects of thyroid hormones on O₂ consumption and metabolic rate. In what ways do the thyroid hormones cause those effects? State whether the responses to thyroid hormones are immediate or whether they take some time to develop?

Answer 1

Thyroid hormone stimulates the metabolic processes of the tissue and increases basal metabolic rate.Therefore,it increases the heat production of the body due to increases o2 consumption and subsequent ATP hydrolysis.Thyroid hormones causes these effects through - lipid and carbohydrate metbolism.

Elevation in  thyroid hormones stimulates the fat mobilization and further increases fatty acid into plasma.Increased cholesterol in plasma negatively regualte the thyroid hormones secretion.

Thyroid hormones tend to stimulate Carbohydrate metabolism,increases gluconeogenesis and glycogenolysis to generate free glucose.

The responses of the thyroid hormones depends on the T4 hormone in blood stream.If level of T4 is high in blood stream then pituitary gland produces less Thyroid stimulating hormone (TSH) and causes thyroid responses slow.Conversly, if T4 is low in bloodstream,then Pituitary gland releases tremedous TSH to elevate the metabolism process immediately.