Thyroid Flashcards by Mark Next

Controls metabolic rate

thyroxin

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lowers blood calcium levels by removing from the blood and putting into the bone

calcitonin

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Complete lack of thyroid secretion results in the basal metabolic rate of the body to decrease by ___ to ___ %

40 to 50

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Extreme excess of thyroid secretion can increase basal metabolic rate by __ to _____ percent above normal

60 to 100

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The thyroid is butterfly shaped and located immediately below the _____, anterior and to each side of the trachea

larynx

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The thyroid is one of the largest endocrine glands and weighs about

15-20 grams in adults

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What three hormones does the thyroid gland produce

Thyroxine (T4), Triiodothyronine (T3), reverse T3 (rT3 - inactive)

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Thyroid gland also produces _______ which is important for calcium regulation

calcitonin

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Thyroid gland is made of follicles of ____ epithelial cells surrounding a colloid matrix

cuboidal

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________ is required for thyroid hormone synthesis

iodine

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___ and ___ are the most important thyroid hormones for metabolic control

T4 and T3

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The thyroid secretes 93% ______ and 7% _______, though nearly all is converted to ___ in the tissues

Thyroxine (T4) / Triiodothyronine (T3) / T3

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__ is 4x more potent than ___, but is more scarce and is cleared more rapidly

T3 / T4

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Thyrotropin releasing hormone is released by the _______

hypolthalamus

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TRH causes release of ______ by the ____ ______

TSH / anterior pituitary

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TSH causes release of __ and ___ from the thyroid gland

T3 and T4

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Only _____ TH is active, but over 99% is bound to protein, either Thyroxin bidning globulin or albumin

free

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Thyroid hormone is slowly released from ______ and then taken up by ____ _____

protein / peripheral tissues

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Peripheral tissues contain _____ that convert ___ to ___ (T3 is more metabolically active)

enzymes / T4 / T3

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TH activate _______ processes which increase gene transciption, protein and enzyme production which increases metabolic rate

intracellular

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TH increases the size and number of ______, which are the energy generators of cells

mitochondria

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T/F It is likely that all cells in the body are targets for thyroid hormones

TRUE

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Thyroid hormones in general effect what?

metabolism, growth, development

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Thyroid hormone stimulates ________ metabolism by increasing uptake of glucose by cells and by the ___ tract. It further enhances ____,____,____

carbohydrate / GI / glycolysis, gluconeogensis, insulin secretion

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Thyroid horomone stimulates fat metabolism by mobilizing lipids, decreasing fat stores and decreasing ___________

cholesterol

Thyroid hormone INCREASES the requirements for vitamins because vitamins are needed for increased _______ synthesis

enzyme

Thyroid hormone increases the basal metabolic rate because metabolism is _______ in almost all cells

increased

Thyroid hormone can decrease body weight but this does not always occur because it can also increase _______

appetite

Cardiovasular effects of Thyroid Hormone - ______ blood flow secondary to vasodilation

increased

Cardiovasular effects of Thyroid Hormone - ______ cardiac output

increased

Cardiovasular effects of Thyroid Hormone - _______ heart strength and heart rate

increased

Cardiovasular effects of Thyroid Hormone - _______ MAP (increased SBP, decreased DBP, increased PP)

normal

Cardiovasular effects of Thyroid Hormone - _______ respiration because more C02 is produced

increased

Cardiovasular effects of Thyroid Hormone - Increased number and affinity of ______ receptors

beta-adrenergic

Cardiovasular effects of Thyroid Hormone - Decreased number of cardiac _____ receptors

alpha

CNS effects of thyroid hormone

increased mentation, but also increased anxiety and neurosis

Muscular effects of thyroid hormone

muscles more vigorous, become weak with protein catabolism

Thryoid hormone sleep effects

causes exhausted/excitable effects, constantly tired but can't sleep

Endocrine effects of thyroid hormone

increases both secretion by glands, but also need for hormone from peripheral tissues

Sexual - Lack of thyroid hormone causes loss of _____ while excess can cause ______

libido / impotence

Hypothyroidism is a condition where the thyroid does not make an adequate amount of thyroid hormones. Symptoms inlcude (these are underlined)

cold intolerance, depression, fatigue, joint pain, thin brittle nails, weakness. Additional symptoms are weight gain, consitpation, decreased taste and smell, hoarseness, menstural disorders, puffy face hands and feet, thickening of skin, brittle hair, thinning of eyebrows

** Primary hypothyroidism is where __ and ___ are not produced because of problems with the thyorid gland itself. It is most commonly due to _______ and surgical removal of thyroid tissue. Other causes for primary hypothyroidism include inadequate dietary iodine, radiation exposure, lithium, surgery

T3 and T4 / Hashimoto's thyroiditis

**Secondary hypothyroidism is from inadequate T3 and T4 due to _____ not being release from the Pituitary

TSH

**Tertiary hypothyroidism is from inadequate T3 and T4 due to lack of ______ from the hypothalamus

TRH

Hypothyroidism that occurs in infancy leads to MR and growth deficits. This is called __________

cretinism

The most severe form of hypothyroidism is _____ _____

myxedema coma

Myxedma coma is a rare condition that is triggered by ILLNESS, INFECTION, EXPOSURE TO COLD, MEDICINES. Sympoms include what?

coma, decreased breathing, decreased blood sugar, decreased BP, decreased temperature

_______ is the standard test for thyroid function

Serum T4 assay

Total T4 elevated in 90% of people with _______

hypethyroidism

Total T4 low in 85% of people with _______

hypothyroidism

T4 levels are affected by levels of ____

TBG

Blood levels of T3 and T4 are low in _______

hypothyroidism

Blood levels of TSH are _____ in primary hypothyroidism

HIGH

Blood levels of rT3 are high in _______ sick states (critical illness)

euthyroid

Levothyroxine is ____ and is the most commonly used med

Armour thyroid contains __ and __

T3 and T4

Hypothyroidism and Anesthesia - Elective surgery should be postponed until _______ state is achieved but this is not always done

euthyroid

Associated problems with hypothyroidism and anesthesia

lethargy, hypotension, bradycardia, CHF, gastroparesis, hypoglycemia, hypothermia, hypoventilation, hyponatremia. Basically everything is in the toilet

Anesthesia management of hypothyroidism - Be aware of _____ on induction possibility. _________ is frequently used on induction. Volatile agents are not recommended due to the sensitivity of the ______ to depression. Pancuronium/rocuronium have vagolytic/sympathmomimetic effects. Art line is indicated with PAC in setting of cardiac failure.

crash / ketamine / myocardium

Hyperthyroidism is a condition of thyroid gland ______

overactivity

_______ is inflammation of the thyroid which causes release of excessive hormone but not increased ___________

thyroiditis / production

Thyrotoxicosis is an oversupply of thyroid hormones on _______

peripheral tissues

Symptoms of Hyperthyroidsim

palpitations, nervousness, breathlessness, fatigue, tachycardia, muscle weakness, hair loss, heat intolerance, insomnia, increased BMs, light or absent menstrual cycles, trembling hands, warm moist skin, staring gaze (exopthalmos)

With Hyperthyroidism, symptoms begin slowly and diagnosis is not made until _______ worsens

severity

Most common cause of hyperthyroidism is _______ which is an autoimmune dz

grave's

In Grave's dz, autoantibodies activate the _____ receptor. Causes multinodular goiter. Stimulates thyroid hormone synthesis, ______ and thyroid growth.

TSH / secretion

Exopthalmos is caused by inflammation of the eye muscles by attacking ________

autoantibodies

Range of treatment for Hyperthyroidism

suppressive medicines, permanent surgical or radioisotope therapy

Antithyroid drugs inhibit production of ____. Examples are____ and ____. They inhibit ______ of thyroglobulin and conversion of T4 to T3

TH / methimazole and PTU / iodination

Propanolol has two roles in hyperthyroidism. What are they

The L-isomer causes beta-blockade, treats tachycardia, tremor, palpitations, anxiety and heat intolerance. The D-isomer inhibits conversion of T4 to T3

One time dose in pill form that results in destruction of thyroid tissue

radioactive iodine

A partial or total thyroidectomy can be performed but not used extensively in absence of ______ as meds are efffective and risk of removing parathyroids or RLN nerve

cancer

Thyroid storm is an extreme form of hyperthyroidism that typically occurs within ___ to ___ hours post op

6 to 18 hrs

S/S of thyroid storm

hyperthermia, tachycarida, dysrhythmias, CHF and shock

Causes for thyroid storm

surgery, infection, trauma, toxemia, DKA

Treatment for the hyperthyroid aspect of thyroid storm

sodium iodide, inderal/labetolol, cortisol, PTU

Treatment for the hyperthermic aspect of thyroid storm

acetaminophen, cooling blankets

Treatment for the hydration aspect of thyroid storm

Fluids and glucose (increased metabolism)

Prep for elective and emergent surgery for hyperthyroidism involves checking the airwya, administering antithyroid drugs, treating symptoms of hyperdynamisim, and treating ______ depletion and ______ problems

volume / electrolyte

T/ F For elective surgery and hyperthyroidism goals include relief of tremor, relief of heat intolerance and relief of nervousness. Resolutioin of hyperthyroid related murmurs, return to normal pulse presure and sinus rhythm

TRUE

Sodium iodide and propanolol treatment lead to euthyroidism in about __ days

Antithyroid drugs 6-8 weeks prior to surgery include _____ and ______

sodium iodide and PTU

Treat hyperdynamism with

beta blockers

For emergency surgery on the hyperthyroid patient you want to administer antithyroid drugs like sodium iodide, PTU and cortisol which blocks peripheral conversion of ____ to ___ (making rT3 instead)

T4 to T3

T/F the hyperthyroid patient may require lower doses of premedication to decrease anxiety

FALSE - they may require higher doses

How would you treat heart failure in the hyperthyroid patient going for emergent surgery?

digitalis

What meds do you want to avoid in the hyperthyroid patient

halothane and atropine

Goiter means enlargement and results from chronic stimulation by _____ or can occur in ____ deficiency states

TSH / iodine

Intraoperative monitoing for thyroidectomy would include what?

neuro monitoring through a NIM tume or Dragonfly monitor

**Post op concerns after thyroidectomy

RLN or SLN damage, hematoma, hypocalcemia, tracheomalacia

**Unilateral RLN injury results in ______

hoarseness

**Bilateral RLN injury results in

aphonia, stridor, aspiration

**SLN injury results in abnormal voice in upper ______

registers

**Hematoma after thyroidectomy is an _____ emergency requiring decompression and rapid intubation before _____ compromise

airway / airway

**Hypocalcemia after thyroidectomy is due to inadvertent removal of _______ glands

parathyroid

**Symptoms of hypocalcemia

weakness, tetany, laryngospasm 24-72 hrs later

**How can severe hypocalcemia end

cardiovascular collapse

**With tracheomalacia, there is tracheal softening and airways collapse with ______

inspiration

Thyroid Flashcards

(98 cards)