What is the target organ of thyroid hormones' metabolic effects? what is the target organ of thyroid hormones' metabolic effects? hypothalamus anterior pituitary thyroid cells of the body?

Answer is: target organ of thyroid hormones metabolic effects are cells of the body.
Thyroid hormones (T₃,T₄) are tyrosine based hormones produced by the thyroid gland. Tyrosine (4-hydroxyphenylalanine) is one of the 20 standard amino acids.
Effects of triiodothyronine (T₃) are: increases heart rate, increases basal metabolic rate, brain development, increases catabolism of proteins and carbohydrates.