HPT Axis

Question 1

WHat is the main function of the HPT axis?

Answer 1

Make T3/T4

Question 2

What does the hypothalamus release

Answer 2

TRH

Question 3

Anterior pituitary release

Answer 3

TSH

Question 4

What does the thyroid release

Answer 4

T3/T4

Question 5

TSH inhibits _____

Answer 5

TRH

Question 6

WHat are some affects of T3/T4

Answer 6

Bone growth/maturation
CNS maturation
Increase BMR and heat production
Increase body metabolism
Increase CO

Question 7

Where is the thyroid gland

Answer 7

In the neck

Question 8

What kind of cells are in the thyroid

Answer 8

Follicular epithelial cells

Question 9

What do follicular epithelial cells make

Answer 9

Thyroid hormone

Question 10

What is thyroglobulin

Answer 10

A protein that binds and helps form thyroid hormone

Question 11

What molecule does thyroid synthesis require

Answer 11

Iodine

Question 12

Thyroid hormone is made by step wise addition of iodine to tyrosine
-only T3/T4 have biological fxn

Answer 12

Know this

Question 13

Which hormone is more potent T3 or T4

Answer 13

T3

Question 14

Which hormone is made faster T3 or T4

Answer 14

T4

Question 15

What is T4 converted to

Answer 15

T3

Question 16

1. Iodide is pumped into the cell from blood
2. Forms iodine
3. Iodine binds tyrosine on thyroglobulin
4. Makes MIT/DIT
5. DIT+DIT: T4
   DIT+MIT: T3

Answer 16

Know this

Question 17

DIT+ DIT:

Answer 17

T4

Question 18

DIT+MIT:

Answer 18

T3

Question 19

What happens when thyroglobulin is stimulated

Answer 19

Is brought into the cell and T3/T4 are removed and secreted into circulation

Question 20

Where do we get iodine from

Answer 20

Our diet

Question 21

What is the needed intake of iodine

Answer 21

150 up

Question 22

Where does the majority of the iodine go?

Answer 22

Thyroid

Question 23

What degrades T3/T4?

Where does it go?

Answer 23

Liver and send its back to blood

Question 24

What secretes the majority of iodine

Answer 24

Kidney

Question 25

T/F

T3/T4 is easily dissolved in the blood

Answer 25

False

Question 26

T/F only free T3/T4 can be sensed/regulated/and degraded

Answer 26

True

Question 27

What kind of hormone is T3/T4

Answer 27

Peptide hormone but it acts like a steroid

Question 28

What carries T3/T4

Answer 28

Binding proteins

Question 29

What receptor type does T3/T4 bind to

Answer 29

Intracellular

Question 30

Does T3/T4 directly or indirectly initial transcription errors

Answer 30

Directly

Question 31

____ is more potent

Answer 31

T3

Question 32

____ is produced more

Answer 32

T4

Question 33

What enzyme converts T4 to T3 in our tissues

Answer 33

Iodinated

Question 34

How does T3/T4 increase BMR

Answer 34

Increase Na/K ATPase activity
Increase O2 consumption
Increase heat production

Question 35

How does T3/T4 increase metabolism

Answer 35

Increase availability and uptake of glucose/proteins/fat

Question 36

What is hyperthyroidism

Answer 36

Too much T3/T4

Question 37

What are some causes of too much T3/T4 in hyperthyroidism

Answer 37

Grave’s Disease
Thyroid tumor
TSH/TRH secreting tumors

Question 38

What are some symptoms of hyperthyroidism

Answer 38

Weight loss
Heat intolerance
Sweating
Increased CO
Exophthalmos
Goiter

Question 39

How do you treat hyperthyroidism

Answer 39

Remove thyroid/tumor

Question 40

What is hypothyroidism

Answer 40

Not enough T3/T4

Question 41

What are some symptoms of hypothyroidism

Answer 41

Weight gain
Cold intolerance
Low CO
Mental slowness
Lack of energy
Myxedema (swollen puffy skin)

Question 42

What is the treatment for hypothyroidism

Answer 42

Give them exogenous T3/T4 or iodine

Question 43

What is a goiter

Answer 43

Enlarged thyroid gland

Question 44

Does goiter occur in hypo or hyperthyroidism

Answer 44

Both