Thryroid 1 Flashcards
Where is the thyroid situated in the neck
in front of the larynx and trachea at the level of the 5th, 6th and 7th cervical and 1st thoracic vertebrae
Anatomic vatiation of thyroid
Lingual thyroid
What is seen with lingual thyroid
Thyroid is embedded in the tongue
And there is no thyroid gland in the neck
Arterial blood supply to thyroid
Superior and inferior thyroid arteries
superior thyroid artery is branch of
branch of the external carotid artery
inferior thyroid artery is branch of
subclavian artery
venous return of the thyroid gald is ____ and they drain into ______
thyroid veins and they drain into internal jugular veins
where do the parathyroid glands lie
in the posterior thyroid tissue
______ passes upward close to the lobes of the gland
recurrent laryngeal nerve
recurrent laryngeal nerve on right side lies near the ______
inferior thyroid artery
________ is essential for the formation of the thyroid hormones T3 and T4
iodine
main dietary source of iodine in western culture
iodinated table salt
what is iodine trapping
the thyroid gland selectively takes up iodine from the blood
what stimulates release of T3 and T4 into the blood
thyroid stimulating hormone (TSH)
TSH is secreted by
pituitary
secretion of TSH is stimulated by
thyrotrophin releasing hormone (TRH) from the hypothalamus
T3 + T4 and TSH secretion work in a ______ mechanism
negative feeback
how do T3 and T4 cells affect the body?
increase metabolic rate and heat production
metabolism of carbs, proteins and fats
other organ/systems affected by thyroid hormone
heart, skeletal muscle, skin, digestive and reproductive system
increased T3 and T4 secretion=
hyperthyroidism
decreased T3 and T4 secretion =
hypothyroidism
3 thyroid function tests
TSH, T4 and anti-TPO Ab
first line test for assessment of thyroid function
TSH test
high levels of TSH indicate
hypothyroidism
