Chapter 76 Flashcards
The thyroid is found below what?
The Larygneal prominence.
What 3 things will the thyroid gland control?
- How quickly the body burns energy. 2. How quickly the body makes proteins. 3. How sensitive the body should be to other hormones.
What is the major cell type in the thyroid gland?
Follicular.
What is the difference between T3 and T4?
T3 is 4 times as biologically active.
Thyroglobulin stores what?
Tyrosine
Where is thyroglobulin made and stored?
Made and stored in the thyroid gland.
What directly influences the trapping of iodine in the thyroid gland?
TSH
What happens to the thyroid gland in areas of the world with iodine lacking from diet?
They get enlarged and swollen, because there is a surge of TSH.
What is the Number 1 cause of thyroid problems worldwide?
Iodine deficiency
What is the Number 1 cause of thyroid problems in the U.S.?
Autoimmune disease.
93% of the hormone created in the thyroid gland is what (give both names)?
thyroxine aka T4
What is iodine recyling?
75% of tyrosine remains as mono- and diiodotyrosine which can be cleaved by deiodinase enzymes resulting in free iodine that can be used again.
An absence of deiodinase enzyme will result in what?
An iodine deficiency.
Only what form of T3 can be biologicaly active?
Only free thyroid hormones that don’t have a plasma protein bound to them.
T3 or T4 which hormone has a greater binding affinity for plasma proteins?
T4.
How long will it take for T3 and T4 hormones to be released to the tissues?
T3- 50% every day. T4- 50% every 6 days.
In general thyroid hormones do what?
Increase metabolic activity.
Hypothyroid equals what?
Retarded physical growth.
Hyperthyroid equals what?
Excessice growth.
What are the thyroid hormones effects of carbohydrates and fats?
They stiumulate almost all aspects of carbohydrate and fat metabolism.
Thyroid hormone is inversely proportional to what?
Total serum cholesterol levels.
Low levels of thyroid hormone leads to what?
Excessive deposition of fat in the liver and severe atherosclerosis.
What will excess thyroid hormone secretin do to basal metabolic rate (BMR)?
Can increase it up to 60-100%.
A relative vitamin deficiency can occur when?
With thyroid hormone excess.
Increased thyroid hormones will do what to cardiovascular function?
Increase the blood flow and therefore increase the cardiac output as much as 1.5 times normal.
Severe hyperthyroid may lead to what?
Myocardial failure.
What are the sexual effects of thyroid problems in women and men?
Women- menorrhagia, polymenorrhea, oligomenorrhea, or amenorrhea. Hypothyroid = low libido. Men- Hypothyroid= low libido, and hyperthyroid = impotence.
How will hyper and hypothyroidism effect GI motility?
Hyper- diarrhea and hypo- constipation.
How will hyper and hypothyroidism effect the excitation of the CNS?
hyper- nervousness, anxiety, paranoia. Hypo- poor memory, concentration problems.
How will hyperthyroidism effect muscle function?
weakness and muscle tremors.
how will hypothyroidism effect muscle function?
Sluggishness with delayed slow DTR.
How will hyper and hypothyroidism effect sleep?
Hyper- insomnia and eventual exhaustion due to over-stimulated CNS. Hypo- Hypersomnia= tendency to sleep excessively.
What happens to the endocrine glands with hyperthyroidism?
general spike in metabolism.
Increased TSH can do what to the thyroid gland?
Increase in thyroglobulin stored and can cause T3/T4 to be released within 30 minutes.
Is a TSH test alone enough to determine thyroid problems?
No.
What other tests besides TSH should be done?
T3 and T4.
Why would autoantibodies be tested in connection to thyroid problems?
Because autoimmune disease is the number 1 cause of thyroid problems in the U.S.
What type of imaging is good to test glands?
Ultrasound.
What will a possible cancer nodule on the thyroid gland look like?
Irregular border.
What is used to perform a scintigraphy of the thyroid gland?
Radioactive iodine-123.
What is the medical treatment of hypothyroidism?
Levothyroxine which is a stereoisomer of thyroxine (T4) once a day, and it degrades slower.
Graves disease is an autoimmune disease of thyroditis and how is it treated?
Thioamide drugs.
How are thyroid tumors and hyperthyroidism treated?
With radioactive iodine.
cancer?
Percutaneous Ethanol injections.
What is the perferred treatment for thyroid cancer?
A complete thyroidectomy.
What happens to the Basal metabolic rate with hypothyroidism?
It can fall to 40-50% of normal.
What are the symptoms of hypothyroidism that were highlighted in the notes?
Fatigue, weight gain, Thinning of outer 1/3 of eyebrow, Heat intolerance, impaired memory, osteoporosis, high serum cholesterol, Decreased libido, decreased sense of smell and taste.
What is Hashimoto’s disease?
hypothyroidism.
What happens with hyperthyroidism?
Increased activity.
What happens to the Basal metabolic rate with hyperthyroidism?
It can rise to 60-100% above normal.
What happens to wight and appetite with hyperthyroidism?
Major clinical weight loss and ravenous appetite.
What type of treatment is given for hyperthyroidism?
suppressive thyrostatic medicatin and surgery, or radioisotope therapy.
What will all approaches to treat hyperthyroidism have as a possible side effect?
May cause under activity of thyroid gland. So thyroid hormones will be supplemented.
What do Beta-blockers do for treatment of hyperthyroidism?
They only mask the common symptoms like palpitations, trembling and anxiety.
What is the radioactive iodine given to destroy the hyperactive thyroid gland?
Iodine-131
