Thyroid Review Flashcards
Complete lack of thyroid secretion results in the basal metabolic rate of the body to decrease by __ to __ percent.
- 40
- 60
An extreme excesses of thyroid secretion can increase basal metabolic rate by __ to __ percent above normal.
60-100%
T/F: The thyroid is shaped like a butterfly.
TRUE
The thyroid produces what harmones?
- Thyroxine (T4)
- Triiodothyronine (T3)
- Reverse T3 (rT3)-inactive
- Calcitonin
(Thyroid glands) Cells that surround the colloid matrix are:
follicles of cuboidal epithelial cells
T/F: Iodine is NOT required for thyroid hormone synthesis.
FALSE
The thyroid produces __% thyroxine and __% of triiodothyronine.
- 93
- 7
The difference between T3 and T4 is:
- T3 is 4 times more potent than T4
- T3 is less in the body
- T3 is cleared more rapidly
Describe in sequence the how thyroid hormones are released starting with TRH.
- TRH (Hypothalamus) cause release of TSH
2. TSH (Anterior pituitary) causes release of T3, T4
How much of the thyroxine hormone is bound to thyroxine binding globulin (TGB) or albumin? (Both are proteins)
99%
T/F: Only 1 % of thyroxine hormone is free meaning that much is active.
TRUE
T/F: Thyroid hormone increases the size and number of mitochondria.
TRUE
What are the cardiovascular effect of thyroid hormone?
INCREASE: -SBP -Pulse pressure DECREASE -DBP
T/F: Thyroid hormone will increase the number and affinity of beta-adrenergic receptors.
TRUE
T/F: Thyroid hormone will increase the number of cardiac alpha-adrenergic receptors.
FALSE
What are some symptoms to look out for with hypothyroidism?
- Cold intolerence
- Depression
- Fatigue
- Thin, brittle fingernails
- Weakness
What are the causes of primary hypothyroidism?
- HASHIMOTO’S thyroiditis
- Surgical removal of thyroid tissue
- to little iodine
- radiation exposure
- lithium
What are the causes of secondary hypothyroidism?
Inadequate T3, T4 due to TSH not being released from the pituitary.(5-10)
What are the causes of tertiary hypothyroidism.
Inadequate T3 T4 due to thyrotropin Releasing hormone (TRH) from the hypothalumus (<5% of cases)
T/F: Hypothyroidism can cause infants to have poor APGAR scores.
FALSE : (Hypothyroidism can cause mental retardation and growth deficits.)
What are the triggers for Myxedema coma?
- illness
- infection
- exposure to cold
- medicines
What is the standard lab test for hypothyroidism?
Serum T4 assay
In a serum T4 assay a person would have hyperthyroidism if they had __% and would be hypothyroidism if they had __ %
- 90
- 85
Levothyroxine has only __ hormone.
T4
