Thyroid Flashcards
Thyroid Gland secretes
triiodothyronine (T3) and thyroxine (T4)
Thyroxine
Is the regulator of body metabolism that influences almost every body function
Thyroid gland
a 2in butterfly-shaped gland located in the neck
What is a necessary component in the synthesis of thyroid hormone?
Iodine
Thyroid gland feedback loop
- Hypothalamus: releasing hormone (TRH)
- Anterior pituitary: TSH
- Thyroid gland: makes T4
- Thyroxine
- Negative feed back to stop Anterior pituitary and hypothalamus
Most common thyroid disorders
Primary thyroid disorders
-Involves the thyroid gland itself
Thyroid dysfunctions are either
Hypo or hyperthyroidism
-enlargement can occur in either
Thyroid problems are more likely in who?
Women
Goiter
an enlargement of the thyroid gland WITH or WITHOUT symptoms of thyroid dysfunction
Excess pituitary TSH
Low iodine levels
If NO symptoms of thyroid disease the goiter is “nontoxic”
Enlargement of the thyroid gland can also occur from
Goitrogens
-substances that promote thyroid gland enlargement (lithium)
Hypothyroidism
Insufficient levels of T3 + T4
- Primary
- Secondary
Primary Hypothyroidism
Increase in release of TSH from pituitary (Excessive release of TSH indicates hypoactive thyroid)
Most common type of hypothyroidism
Hashimoto’s thyroiditis
-an autoimmune disorder
Hypothyroidism: Hashimoto’s
- Thyroid receptor receptor antibodies
- Antithyroglobulin antibody
- Antithyroperoxidase antibody: HALLMARK of disorder
Hypothyroidism Risk Factors
-Females
-Age >50
-Caucasian
-Pregnancy
-History of other
Autoimmune disorders
-Family Hx
-Medications (amiodarone, lithium)
-Treatment for hyperthyroidism
Hypothyroidism: Manifestations (Early)
Cold intolerance Weight gain Lethargy Fatigue Memory deficits Poor attention span Increased cholesterol Muscle cramps Raises carotene levels Constipation Decreased fertility Puffy face Hair loss Brittle nails