Thyroid

Question 1

thyroid hormone is stored in

Answer 1

TGB follicular cells

Question 2

TGB follicular cell secrete what?

Answer 2

calcitonin

Question 3

T4 is completely active or inactive?

Answer 3

inactive, it’s a prohormone

Question 4

T3 is biologically active or inactive?

Answer 4

active

Question 5

T4 and T3 are all derived from what?

Answer 5

tyrosine, like the catecholamines

Question 6

where is tyrosine taken up from?

Answer 6

the blood

Question 7

after tyrosine is taken up from the blood what two reactions occur??

Answer 7

iodination and conjugation

Question 8

how is thryoglobuline (TGB) formed? by synthesis of what

Answer 8

peptide chains in the ER + glycosylation in the golgi

Question 9

iodination and conjugation occur within what?

Answer 9

TGB at apical border of the cell

Question 10

Thyroid hormones are stored

Answer 10

within the TGB in colloid for up to 2 montsh

Question 11

mechanism of secretion

Answer 11

endocytosis of colloid into follicular cells

Question 12

how much T4 is secreted?

Answer 12

90ug a day

Question 13

how much T3 is secreted?

Answer 13

4 ug a day

Question 14

fate of T4 secreted is 35% converted into

Answer 14

T3

Question 15

fate of T4 secreted is 45% converted to

Answer 15

reverse T3

Question 16

fate of T4 secreted is 20% is

Answer 16

destroyed

Question 17

what is T4’s 1/2 life?

Answer 17

long ~6 days

Question 18

what is T3’s 1/2 life?

Answer 18

pretty long ~1-3 days

Question 19

what kind of receptor does T3 have?

Answer 19

nuclear receptor

binds to nucleus and alters transcription

Question 20

T3 is basically what kind of hormone?

Answer 20

a maintenance hormone

Question 21

what is T3 required for??

Answer 21

growth process!!

Question 22

if deficient in T3 you get

Answer 22

dwarfism

Question 23

if you have excess T3 you get

Answer 23

stunted growth

Question 24

T3 deficiency in children in the nervous system causes what?

Answer 24

cretinism, mental retardation

Question 25

when must T3 be present or else cretinism is permanent?

Answer 25

during the 1st 3 months of life

Question 26

T3 deficiency in adults causes

Answer 26

listless, sleepy, weak

Question 27

T3 excess in the nervous system causes

Answer 27

hyper excitability

Question 28

in terms of protein metabolism, excess T3 causes

Answer 28

increased gluconeogenesis, protein loss

Question 29

in terms of protein metabolism, deficiency in T3 causes

Answer 29

myxedema, accumulation of mucopoly, a saccharide in skin

Question 30

T3 is needed for normal function in many things… like:

Answer 30

lactation
digestion
kidney function
cardiovascular function
reproduction
heat production

Question 31

graves ideas is what type of thyroid state?

Answer 31

hyperthyroid state

associated with protrusion of eyes

Question 32

hypothyroidism symptoms include:

Answer 32

sluggishness
mental retardation
reduced growth rate
thick/dry skin
sensitive to cold
increased sleep

Question 33

causes of hypothyroidism include:

Answer 33

poor development of thyroid
thyroid insensitive to TSH
or hashimoto’s disease