Thyroid Physiology

Question 1

Thyroid Follicles

Answer 1

Serve as a factory and warehouse for thyroid hormones.

Question 2

Fabrication of thyroid hormone is conducted by?

Answer 2

Thyroid Peroxidase

Synthesis of T3 and T4

Question 3

Iodine is essential for the synthesis of?

Answer 3

Thyroid hormones

100-200 mcg is sufficient.

Question 4

Parafollicular cells

Answer 4

C-cells

product calcitonin

Question 5

Calcitonin

Answer 5

Release is dependent on serum calcium levels
Decrease bone osteoclast activity
Inhibits tubular reabsorption of calcium by kidneys

Question 6

Thyroid-releasing Hormone (TRH)

Answer 6

Secreted by hypothalmus

Stimulates pituitary to produce thyroid stimulating hormone

Question 7

When is TRH released?

Answer 7

When T3 and T4 levels are low

Question 8

Thyroid stimulating hormone

Answer 8

Secreted from cells in the anterior pituitary called thyrotrophs.
Increase iodide uptake
Stimulates thyroid gland to release T3 and 4

Question 9

T4

Answer 9

Thyroxine
Greater than T3
Lasts longer in blood than T3
1/4 as potent as t3
T4 converted into T3 so it can act

Question 10

T3

Answer 10

Triiodothyronine
Active form of the hormone
most is produced by deiodination of T4
T3 is 4 times more potent than T4

Question 11

Tg (Thyroglobulin)

Answer 11

Large glycoprotein

Storage form of inactive thyroid hormones and iodine

Question 12

TBG

Answer 12

Thyroxine Binding Globulin
Carrier
Carries T3 and 4

Question 13

Transthyretin (TTR)

Answer 13

Also a carrier of T3 and 4

Less affinity

Question 14

Thyroid hormones are primary regulator of?

Answer 14

Basal Metabolic Rate

Question 15

Metabolic affects of Thyroid Hormons

Answer 15

Increases glucose absorption and insulin secretion. Enhances glycolysis and gluconeogenesis
Enhances all aspects of fat metabolism

Question 16

Developmental effects of thyroid hormone

Answer 16

Essential for growth and development of fetal and neonatal brain.

Question 17

Cardiovascular effects of thyroid hormone

Answer 17

Increased CO
Increased HR
Widening of a pulse pressure.
Increased respirations

Question 18

Plasma and liver fat effects of thyroid hormone

Answer 18

Decreases concentration of cholesterol, phospholipids, and triglycerides in plasma.

Question 19

Thyroid hormone decreases vitamin requirements. T or F?

Answer 19

False. It increases vitamin requirements.

Question 20

CNS effects of thyroid hormone

Answer 20

Hypothyroid patients are seen to have impaired attention, slowed motor function, poor memory.

Question 21

Reproduction and Thyroid

Answer 21

Hypothyroid is associated with infertility, miscarriage, menstrual disorders, poor semen quality

Question 22

Thyroid hormone is also essential for bone development, mitochondrial activity and skeletal muscle reaction..

Answer 22

Believe it