Endocrine Function II

Question 0

List the thyroid hormone secreted in the greatest quantity.

Answer 0

T-4 is the main secretory product

Question 1

List three thyroid binding proteins.

Answer 1

1 Throxine Binding Globulin (TBG)
2 Transthyretin (Thyroxine Binding Prealbumin) (TBPA)
3 Albumin

Question 2

List the most potent, biologically active thyroid hormone.

Answer 2

T-3

Question 3

Describe the structure and clinical significance of increased levels of reverse T-3.

Answer 3

biologically inactive form favored under stress

Question 4

What is the cause of hyperthyroidism in Graves’ Disease?

Answer 4

autoimmune etiology; autoantibodies bind to TSH receptors in thyroid; the body thinks it is getting TSH but it is fooled by antibodies

Question 5

What is the cause of hyperthyroidism in toxic multinodular goiters?

Answer 5

discrete portions of thyroid not under normal feedback control; no exophthalmopathy but still producing thyroid hormone

Question 6

What is the cause hyperthyroidism in solitary toxic adenoma?

Answer 6

patients have thyroid nodules that avidly concentrate injected radioactive iodine; this benign tumor does not respond to normal feedback control

Question 7

These are nodules concentrate injected radioactive iodine.

Answer 7

hot nodules

Question 8

What causes hyperthyroidism in subacute thyroiditis?

Answer 8

inflammation of the thyroid gland; appears to be viral in origin; follicles become inflamed and disrupted

Question 9

What causes hyperthyroidism in iatrogenic symptoms?

Answer 9

adverse mental or physical conditions caused by a medical procedure/physician

Question 10

What causes hyperthyroidism in factitious symptoms?

Answer 10

Disorders that are not genuine or natural; physical or psychological symptoms are produced under the voluntary control of the patient

Question 11

What causes hyperthyroidism in TSH-dependent hyperthyroidism?

Answer 11

caused by excess placental hormones (hCG) and TSH-secreting pituitary tumors (tertiary in hypothalamus)

Question 12

List some symptoms associated with hyperthyroidism

Answer 12

heat intolerance, flushing, perspiration, increased appetite, weight loss, tachycardia, SOB, nervousness

Question 13

List typical T-4, T-3, TSH, and/or TRH levels

-Graves’ Disease

Answer 13

Increased T-3/T-4 and Decreased TSH

Question 14

List typical T-4, T-3, TSH, and/or TRH levels

-Toxic multinodular goiter

Answer 14

Increased T3/T4 and decreased TSH

Question 15

List typical T-4, T-3, TSH, and/or TRH levels

-Solitary toxic adenoma

Answer 15

Increased T3/T4 and Decreased TSH

Question 16

What are the five causes of adult hypothyroidism?

Answer 16

intrinsic disease of the thyroid, total thyroidectomy, complete blockage of thyroid function by irradiation or an antithyroid drug, or various diseases

Question 17

What is the cause of hypothyroidism in cretinism?

Answer 17

failure to develop a thyroid gland in utero; if mother receives antithyroid drugs or radioactive iodine during pregnancy; if maternal antithyroid antibodies cross placenta (results in mental retardation)

Question 18

What causes hypothyroidism in Hashimoto’s thyroiditis?

Answer 18

most common cause of hypothyroidism; autoimmune, chronic inflammatory disease of thyroid in which T-helper cells stimulate B-lymphs to produce antithyroid antibodies; defect in organification, causing lymphocytic infiltration of thyroid; makes antibodies against thyroid tissues

Question 19

What symptoms are associated with hypothyroidism?

Answer 19

more common in women; cold intolerance, dry skin, decreased appetite, muscle weakness, slow heart rate, low blood pressure, weight gain, and hoarseness

Question 20

What are typical T3/T4, TSH, and/or TRH levels for hypothyroidism?

Answer 20

decreased T3/T4, increased TSH (primary); decreased T3/T4, decreased TSH (secondary/tertiary)

Question 21

What is the most common cause and typical total T4 and TSH levels in euthyroid “sick” syndrome?

Answer 21

Caused by Increase in level of serum binding proteins in certain diseases; no evidence of thyroid diease; decreased T3/T4 and normal TSH

Question 22

Differentiate TSH levels associated with hypothyroid vs euthyroid “sick” patients.

Answer 22

Hypo: increased TSH, decreased T3/T4; Euthyroid: increased reverse T3, decreased T3/T4, normal TSH (increased with treatment), no signs/syptoms, normal thyroid