Adrenal Medulla, Thyroid, and Reproductive Endocrinology

gathered from homework and reference ranges

endocrine problem defective sites

primary, secondary, tertiary

target gland, pituitary, hypothalamus

______ and the target gland cause circulating levels of hormones to control the anterior pituitary secreting hormones

hypothalamus

parent substance of all steroid hormones

cholesterol

what hormone parallels the activity of the corpus luteum by rapidly increasing following ovulation and then abruptly failing to initial low concentrations before menstruation starts?

progesterone

most potent estrogen and substance considered to be the true ovarian hormone

estradiol

which hormones does the placenta secrete? (both protein and steroid)

HCG, progesterone, estrogen, HPL

what does an elevated TRH cause?

increased TSH blood concentrations

increase in prolactin

where is calcitonin made?

parafollicular cells of the thyroid gland

Grave’s disease causes ____T4 and ____TSH

free increased; decreased

primary myxedema causes ____T4 and _____TSH

decreased; increased

T3

• elevated more than T4 in hyperthyroidism

• most active thyroid hormone

• commonly decreased in patients with nonthyroidal illness

deiodination of the outer ring of thyroxine produces

T3 (triiodothyronine)

TSH stimulation test can differentiate which 2 tests?

pituitary hypothyroidism (TSH won’t respond)

hypothalamic hypothyroidism (TSH responds)

purpose of anti-TPO antibodies test

differentiate primary hypothyroidism from Hashimoto’s thyroiditis

vanillylmandelic acid

final metabolite of epinephrine meausred in urine

what measurement to do if you have pheochromocytoma

urine metanephrine

what enzyme deficiency do you have with female pseudohermaphrroditism?

21-alpha-hydroxylase

T3 production

In the liver, T4 manually undergoes the peripheral deionination of the T4 outer ring.

40% of secreted T4 is deiodinated in peripheral tissues to form T3. T3 is 4-5 times more potent than T4 is. They reversibly bind to carrier proteins.

rT3 production

One iodine from the inner ring of T4 is removed to form reverse T3 mainly in the liver. Due to acute stress, chronic stress, or medications, reverse T3 is formed instead of T3.

45% of secreted T4 is deiodinated to form rT3, which is biologically inactive.