Thryoid and GI hormone Test #4 Smith

Question 1

What is the largest gland in the body?

Answer 1

-Thyroid gland

Question 2

T/F

The thyroid gland is extremely well vascularized

Answer 2

True

Question 3

Do you have an active or inactive thyroid gland if you have colloid (thyroglobulin) abundant, large follicles, and cells lining the follicle are flat?

Answer 3

Inactive

Question 4

Do you have an active or inactive thyroid gland if you have small follicles, cells lining the follicle are cuboid, and edges are scalloped with many small resorption gaps resulting from the uptake of colloid?

Answer 4

Active

Question 5

What are the two primary functions of the thyroid?

Answer 5

• Secretion of two biologically active hormones by follicular cells
• Secretion by parafollicular cells

Question 6

What do parafollicular cells secrete?

Answer 6

-Calcitonin

Question 7

What is another name for parafollicular cells?

Answer 7

-C-cells

Question 8

What do follicular cells secrete?

Answer 8

• Thyroxine (T4)

- Triiodothyronine (T3)

Question 9

When does parafollicular cells release calcitonin?

Answer 9

-In response to high blood calcium levels

Question 10

What does calcitonin do?

Answer 10

-Lower blood Ca2+ levels by inhibiting the resorbition of bone by osteoclasts

Question 11

What hormone is formed from vitamin D

Answer 11

1,25-Dihydroxycholecalciferol

Question 12

Where is vitamin D processed?

Answer 12

• Liver

- Kidneys

Question 13

What secretes parathyroid hormone?

Answer 13

-Chief cells in the parathyroid gland

Question 14

What causes Parathyroid (PTH) hormone to be secreted by Chief cells?

Answer 14

-Low blood Ca2+

Question 15

What does 1,25-Dihyroxycholecalciferol do to Ca2+?

Answer 15

• Increases absorption from the intestine

- Increases stores in bone

Question 16

How does PTH mobilize Ca2+?

Answer 16

-Stimulate osteoclasts

Question 17

What are the thyroid hormones synthesized from?

Answer 17

• Iodine

- Tyrosine

Question 18

What thyroid hormone is produced exclusively by the thyroid gland?

Answer 18

-T4

Question 19

What thyroid hormone is produced extrahyroidally from its precursor?

Answer 19

-T3

Question 20

What is the precursor for T3?

Answer 20

-T4

Question 21

What is the vast majority of thyroid hormone produced by the thyroid?

Answer 21

-T4

Question 22

What happens to most T4 that is produced?

Answer 22

-Gets converted to T3

Question 23

T/F

T3 is 4x more potent than T4

Answer 23

True

Question 24

Where is most of T3 made?

Answer 24

Liver

Question 25

What is the inactive form of T3?

Answer 25

rT3

Question 26

What does the hypothalamus stimulate the anterior pituitary to produce?

Answer 26

-TSH (thyroid stimulating hormone or thyrotropin)

Question 27

What does thyrotropin/TSH do?

Answer 27

-Stimulate thyroid gland to produce T4

Question 28

If you have low T4, low T3 or cold exposure what occurs?

Answer 28

-Increase T4 and T3 production

Question 29

T/F | Increasing T4 and T3 is calorgenic

Answer 29

True

Question 30

Feedback inhibition at what level most efficiently inhibits TRH secretion?

Answer 30

-Anterior pituitary

Question 31

What enzyme is responsible for making T3 from T4?

Answer 31

-Deiodinase enzymes

Question 32

T/F | T3 can act independently of HPT axis regulation in peripheral tissues

Answer 32

True

Question 33

What do thyroid hormones target?

Answer 33

- Nuclear receptors | - Modulating gene expressions

Question 34

If you are under stress and or fasting the body converts ___ T4 to T3 and ____ T4 to rT3

Answer 34

Less | More

Question 35

T/F | Without sufficient iodine thyroid hormones are not released and TSH builds up

Answer 35

True

Question 36

The amount of T4 produced and released by the thyroid gland is controlled directly by TSH released by the _____?

Answer 36

Anterior pituitary

Question 37

What is the best known stimuli for increasing the rate of TSH secretion by the anterior pituitary?

Answer 37

-Exposure to Cold

Question 38

What protein are stores of T3 and T4 found?

Answer 38

-Thryoglobulin (TGB)

Question 39

What Thyroid hormone has 4 iodine molecules attached?

Answer 39

-T4

Question 40

T/F | 5' deiodination of T4 results in rT3 which is inactive

Answer 40

False 5' deiodination does T4 to T3 5 deiodination does T4 to rT3

Question 41

What is essential to normal thyroid function

Answer 41

-Iodine

Question 42

What are the only cells in the body that can absorb iodine?

Answer 42

-Thyroid

Question 43

What can cause a Goiter?

Answer 43

-Too much TSH or HCG

Question 44

What do patients with IDD most commonly present with?

Answer 44

-Goiter

Question 45

What is the most extreme manifestation of severe IDD?

Answer 45

-Cretinism

Question 46

What disease is linked to hypothyroidism?

Answer 46

-Hashimoto's disease

Question 47

What disease is linked to hyperthyroidism?

Answer 47

-Graves disease

Question 48

What hormone can act in an endocrine, paracrine, and neurocrine fashion in digestion?

Answer 48

-CCK

Question 49

What is the source of gastrin?

Answer 49

-G cells in stomache

Question 50

What stimulates the release of gastrin?

Answer 50

-Stimuli from consumption and peptides in gastric lumen

Question 51

What is the action of gastrin?

Answer 51

-Stimulate gastric acid secretion

Question 52

What is the source of CCK?

Answer 52

-I cells from duodenum and jejunum

Question 53

What is the stimuli for release of CCK?

Answer 53

-Digestive products of fats, fatty acids, and monoglycerides

Question 54

What is the action of CCK?

Answer 54

-Contract gall bladder expelling bile into small intestine

Question 55

What is the source of secretin?

Answer 55

-S cells in duodenum

Question 56

What is the stimuli for release of secretin?

Answer 56

-Acidic pH in lumen of Small intestine

Question 57

What is the action of secretin?

Answer 57

-Stimulate pancreas to release bicarbonate

Question 58

What is the source of Gastric inhibitory peptide?

Answer 58

-Mucosa of upper small intestine

Question 59

What is the stimuli for release of Gastric inhibitory peptide?

Answer 59

- Fatty acids - Amino Acids - Carbohydrates

Question 60

What is the action of gastric inhibitory peptide?

Answer 60

-Inhibit gastric secretion and increase insulin release

Question 61

What are three major pancreatic hormones?

Answer 61

- Glucagon - Insulin - Somatostatin