Endocrine Function II Part 2

Question 0

Describe lab results found in TSH-Dependent (secondary or tertiary) hyperthyroidism.

Answer 0

Increased T3/T4, increased TSH (thyroid normal but ant. pit. not working), decreased TRF (TRH-secondary) or increased TRF (TRH-tertiary)

Question 1

Describe lab results found in TSH-Independent (Primary) Hyperthyroidism.

Answer 1

Increased T3/T4, Increased Free T4/T3, Decreased TSH (because the ant. pit. is normal), Decreased TBG, Increased THBR, and Decreased TRH (also called TRF); this occurs because negative feedback is turned off and the problem is occurring in the thyroid gland

Question 2

What does the TRH stimulation test differentiate?

Answer 2

Normal response=Tertiary Hypothyroidism; Blunted Response=Secondary Hypothyroidism

Question 3

State the use of Total T3 assays.

Answer 3

Measures both free and bound hormone; aids in diagnosis and monitoring of hyperthyroid patients with decreased TSH and normal Free T4

Question 4

The clinical use of this test is to directly or indirectly assess available TBG binding sites but is not to diagnose hyper- or hypo- thyroidism. May be ordered if the patient has abnormal total T4 or total T3 levels with a normal TSH.

Answer 4

THBR- Thyroid Hormone Binding Ratio with T3 Uptake Test

Question 5

The clinical use of the test is primarily to monitor patients with follicular thyroid cancer (which would be increased); it is the storage form of the thyroid hormone precursors

Answer 5

Thyrogobulin

Question 6

This is the most sensitive and specific mesaure of thyroid activity

Answer 6

TSH

Question 7

This test aids in diagnosis and monitoring of hyperthyroid patients with suppressed TSH levels and normal Free T4 levels

Answer 7

Total T3

Question 8

This test by itself, does not provide enough clinical information and must be reported in conjunction with the other thyroid tests.

Answer 8

Total T4

Question 9

This test provides an approximation of the free hormone concentration in the presence of abnormal TBG levels as TBG or free hormone levels are not easily measured

Answer 9

THBR

Question 10

State the SPECIFIC diagnostic usefulness of the following

-Antithyroidglobulin antibody (TgAb)

Answer 10

Hashimoto’s thyroiditis >85% reactivity, grave’s disease >30% reactivity, and also a tumor marker for recurrence of thyroid cancer

Question 11

State the SPECIFIC diagnostic usefulness of the following

-Thyroid peroxidase autoantibody (TPOAb)

Answer 11

-Hashimoto’s thyroiditis 100% reactivity, Grave’s disease 70-80% reactivity; Ab itself may be cytotoxic to the thyroid

Question 12

State the SPECIFIC diagnostic usefulness of the following

-TSH receptor autoantibody (TRAb)

Answer 12

Immunoglobulins that bind to thyroid cell membranes at or near TSH receptor site; hyperactivity in Grave’s or inability for TSH to stimulate the thyroid in Hashimoto’s; provides differential diagnosis of hyperthyroidism, predicts fetal dysfunction, and predicts course of grave’s patients on antithyroid drug therapy

Question 13

What is the number of carbons present in estrane?

Answer 13

18

Question 14

What is the number of carbons present on androstane?

Answer 14

19

Question 15

What is the number of carbons present on pregnane?

Answer 15

21

Question 16

What is the analytical importance of the phenolic hydroxyl group on carbon #3 on estrane and its derivatives?

Answer 16

Estrogens on carbon #3, androgens do not have this

Question 17

What are the biological effects of estrogen?

Answer 17

primary and secondary sexual characteristics

Question 18

What is the site of production of estrogen?

Answer 18

Graafian follicle of ovaries

Question 19

What is the most potent, physiologically active estrogen?

Answer 19

Estradiol, evaluates ovarian function

Question 20

What is the major post-menopausal estrogen?

Answer 20

Estrone

Question 21

What is the major estrogen produced during pregnancy?

Answer 21

Estriol, decreased in fetal distress and measured to monitor progress of pregnancy

Question 22

Describe the menstrual cycle with the rise and fall of estrogen, FSH, and LH

Answer 22

E2 removes negative feedback for FSH/LH which increases FSH and increases estrogen.

Question 23

What is the SPECIFIC biological effect of FSH in women

Answer 23

Chooses an egg

Question 24

What is the SPECIFIC biological effect of LH in women?

Answer 24

LH stimulates ovulation

Question 25

What is the SPECIFIC biological effect of FSH in men?

Answer 25

Stimulates Leydig cells to produce testosterone and Sertoli cells to produce sperm

Question 26

What is the SPECIFIC biological effect of LH in men?

Answer 26

Stimulates Leydig cells in testes to produce testosterone

Question 27

What is the clinical usefulness of continuously monitoring estriol levels urging pregnancy?

Answer 27

Indicate status of fetoplacental unit; need a premature delivery if sharp decrease in levels

Question 28

What is the historical method for measuring estrogen?

Answer 28

Kober Reaction by GM-MS

Question 29

What is the specific site of progesterone production in pregnant women?

Answer 29

Placenta

Question 30

What is the specific site of progesterone production in non-pregnant women?

Answer 30

Ovarian corpus luteum

Question 31

What are the three uses for progesterone measurement?

Answer 31

1 detect ovulation 2 detect ovarian tumors 3 detect placental dysfunction

Question 32

What are two physiological effects of progesterone?

Answer 32

*prepares the uterus for fertilized egg implantation, important for maintenance of pregnancy, stimulates breast development, increases body temperature

Question 33

Two physiological effects of hCG

Answer 33

Stimulates progesterone production and produced by trophoblasts that becomes the placenta (The alpha subunits is identical to FSH, LH, and TSH)

Question 34

Which sub unit is measured in hCG?

Answer 34

Beta subunit

Question 35

What are four uses for the measurement of hCG?

Answer 35

Detection of hCG producing tumors, detection of multiples, prediction of spontaneous abortion, and pregnancy testing

Question 36

What are two physiological effects of human placental lactogen (HPL)?

Answer 36

Stimulates mammary gland development and monitors decrease in functional placental tissue (stimulates hormone production)

Question 37

What is estriol levels are associated with down syndrome? (Increased or decreased)

Answer 37

hCG Decreased in fetal distress