Endocrine System 3

Question 1

This gland is below the larynx/voice box

Answer 1

Thyroid gland

Question 2

This gland in the neck has 2 lobes connected by an isthmus

Answer 2

Thyroid gland

Question 3

What happens during synthesis of thyroglobulin?

Answer 3

Long chain protein made by follicular cells is transported into the follicular lumen

Question 4

Where are C cells & what do they do?

Answer 4

Parafollicular (between follicles), secrete calcitonin

Question 5

What is iodide trapping?

Answer 5

Follicular cells grab iodide, take it into follicular lumen by protein pendrin

Question 6

How is TSH stimulated?

Answer 6

Thyrotropin releasing hormone stimulates thyrotropes from anterior pituitary, stimulating TSH

Question 7

This gland is composed of many follicles filled with jelly-like (colloidal) thyroglobulin protein

Answer 7

Thyroid gland

Question 8

What occurs during oxidation of iodide?

Answer 8

Iodide -> Iodine by peroxidase & hydrogen peroxide

Question 9

What is organification of tyrosine?

Answer 9

Addition of iodine to tyrosine to form T1 & T2
T1 = 1 iodine
T2 = 2 iodines

Question 10

How is free T3 & T4 produced?

Answer 10

Pinocytosis of thyroglobulin chain by follicular cells and digestion by lysosomal enzymes

Question 11

What increases cellular metabolic activity & BMR?

Answer 11

T3 & T4

Question 12

What can reverse symptoms caused by Cretinism?

Answer 12

Hormone replacement therapy in first few weeks of life

Question 13

Where does organification of tyrosine occur?

Answer 13

Lumen of the follicular cell

Question 14

T3 & T4 are made from?

Answer 14

T1 + T2 = T3, T2 + T2 = T4

Question 15

What is the name for T3?

Answer 15

Triiodothyronine

Question 16

What is the name for T4?

Answer 16

Tetraiodothyronine

Question 17

What series of events occurs when there are low blood levels of T3 & T4?

Answer 17

Stimulates release of TRH -> TRH carried by hypophyseal portal veins to ant pit -> stimulates thyrotropes -> stimulates TSH -> bloodstream -> stimulates individual follicle in each follicular cell -> T3 & T4 released into the bloodstream

Question 18

What occurs after pinocytosis of the thyroglobulin chain?

Answer 18

Secretion of T3 & T4 into the blood

Question 19

What releases calcium & phosphate into the blood and how?

Answer 19

Parathyroid hormone, by osteolysis & osteoclastic bone resorption

Question 20

What happens to thyroglobulin after synthesis?

Answer 20

Sent to the follicular lumen (SEE SLIDE 7)

Question 21

What increases ATP production in the mitochondria?

Answer 21

T3 & T4

Question 22

What occurs after secretion of T3 & T4 into the blood?

Answer 22

Transport of T3 & T4 in the free form or bound to the thyroid-binding-globulin (TBG)

Question 23

What increases the transcription of a large number of genes?

Answer 23

T3 & T4

Question 24

Effects of PTH on cells are mediated by what?

Answer 24

cAMP system

Question 25

What occurs when blood levels of T3 & T4 are increased?

Answer 25

Inhibition release of TRH & TSH, decreased secretion of T3 & T4 by thyroid follicular cells

Question 26

What maintains normal sexual functions & libido?

Answer 26

T3 & T4

Question 27

What is Cretinism caused by?

Answer 27

Hyposecretion of thryoid hormones during fetal development & infancy

Question 28

Symtoms of Cretinism?

Answer 28

Severe mental & physical retardation in newborn

Question 29

What increases phosphate excretion by the kidneys in the urine?

Answer 29

Parathyroid hormone

Question 30

What increases CNS, cardiovascular, respiratory, muscular, & GI activities?

Answer 30

T3 & T4

Question 31

What is hyperthyroidism also called & what are the symptoms?

Answer 31

Graves Disease, high met rate, tachycardia, high body temp, anxiety & irritability, goiter, heat intolerance, weight loss, exophthalmia (eyeballs bulge out)

Question 32

What cells do parathyroid cells contain?

Answer 32

Chief cells & Oxphil cells

Question 33

What promotes normal growth synergistically with Growth Hormone?

Answer 33

T3 & T4

Question 34

How does Calcitonin decrease calcium plasma levels?

Answer 34

Inhibits osteolysis & osteoclastic bone resorption, decreases calcium absorption in intestines, & increases calcium reabsorption by the kidneys

Question 35

What causes an endemic colloid goiter?

Answer 35

Insufficient dietary iodine to make T3 & T4; lack of negative feedback from T3 & T4 causes over secretion of TSH by ant pit gland -> overgrowth of thyroid gland follicles

Question 36

What increases intestinal absorption of calcium & phosphate by activation of vitamin D in the kidneys?

Answer 36

Parathyroid hormone

Question 37

What hormones do chief cells secrete?

Answer 37

Parathyroid hormone

Question 38

What is hypothyroidism also called & what are the symptoms?

Answer 38

Hashimoto's Disease, low met rate, bradycardia, low body temp, goiter, lethargy, cold intolerance, weight gain, myxedema (dry scaly skin)

Question 39

What hormones do Oxyphil cells secrete?

Answer 39

None

Question 40

What decreases calcium excretion by the kidneys in the urine?

Answer 40

Parathyroid hormone

Question 41

Parathyroid cells contain this to detect calcium plasma levels that control PTH secretion?

Answer 41

Calcium-sensing receptor

Question 42

Parathyroid hypertrophy occurs with?

Answer 42

Rickets, Pregnancy, & Lactation

Question 43

What does Calcitonin do?

Answer 43

Decreases calcium plasma levels

Question 44

What is hypoparathyroidism caused by?

Answer 44

Surgical excision of parathyroid during thyroid surgery

Question 45

What does hypoparathyroidism cause?

Answer 45

Fatal tetanus

Question 46

What is hyperparathyroidism caused by?

Answer 46

PT gland tumors

Question 47

What does hyperparathyroidism cause?

Answer 47

Increased calcium plasma levels, inc renal stones formation, soft/fragile deformed bones