Thyroid Function (lect 4)

Question 1

Describe Thyroid Glands

Answer 1

two types of cells follicular and parafollicular

Question 1

Describe follicular thyroid glands
single
secrete

Answer 1

single layer of epithelial cells, spherical, secrete thyroid hormones
hormones in lumina

Question 2

Describe the follicular thyroid hormones

Answer 2

T4 - L thyroxine
T3 - L- trii
RT3 - reverse T3, bioinactive

Question 3

Describe the parafollicular thyroid gland

Answer 3

secrete calcitonin

Question 4

Function of thyroid glands
aid
rate
grow
p
c

Answer 4

aid in regulation of metabolic functions
rate of O2/Heat
growth/sexual maturaty/proteins/carb metabolism

Question 5

Describe H-P-T axis
what is released by hypoth stim and anterior pit secretes?
what regs synth/release of thyroid hormones?

Answer 5

TRH released by the hypothal stim anterior pit to secrt TSH

TSH reg synth and release of thyroid hormones

Question 6

Secretion of TSH is regulated by
what hormones?
what inhibits/
what stimulates the inhibitor? then causes?

Answer 6

TRH, Stomatostatin, F13, FT4

Stomastatin is an inhibitor
FT3/FT4 - stim hypothal. to sec stomastatin/negative feedback

Question 7

T/F 30% of T4 goes through the monod. in tissues to prod. T3

Answer 7

False its 40%

Question 8

Describe RT3

Answer 8

45% Convert to rt3
Bioinactive

Question 9

Thyroid hormones circulate in blood bound to

Answer 9

TBG, TB alb, TB pre-Alb

Question 10

What is the principle carrier protein

Answer 10

TBG

Question 11

T/F FT3/FT4 are physiologically inactive

Answer 11

false they are active

Question 12

T/F T3 is 4-5x more metabolically potent than T4

Answer 12

TRUE

Question 13

Describe tests for thyroid function
generations?

Answer 13

TSH:
assesses function
third gen sensitivity subclinical disease

Question 14

Describe subclinical hypothyroidism
TSH
FT4

Hyperthyroidism:
TSH
FT4

Answer 14

TSH minimal incr
FT4 within range

hyperthyroidism: TSH dec
FT4 normal

Question 15

Describe thyroxine (T4)
bound?
alterations lead to?

Answer 15

99.9% protein bound, alteration leads to outside normal range

Question 16

Describe Trii (T3)
produces____ of___

Answer 16

produces 20% batom iodine

Question 17

Describe free thyroxine (FT4)
most is?
able to?
bio?

Answer 17

small frac. of total because most is bound, able to enter the tissues
bioactive

Question 18

Describe Free Trii (FT3)
elevated in?
what fraction?

Answer 18

hyperthyroid are elevated, low fraction measured less

Question 19

Describe thyroglobulin Ab
destruction…may lead to?

Answer 19

destruction through autoimmune response may result in Tg leakage into blood stream

Question 20

Describe TPO ab
activate…
role in?

Answer 20

activate/compliment role in path of hypothyroidism

Question 21

Describe TrAB Ab
all ____ by TRAB

Answer 21

all autoimmune thyrotoxicosis by TRAB

Question 22

Describe the thyroid autoimmune disorders (2)

Answer 22

graves/hashimotos

Question 23

Describe graves disease
what is +?

Answer 23

hyperthyroidism, goiter growth of gland TSHRAB (+)

Question 24

Describe Hashimotos thyroiditis
another name?
Ab leads to dec____ and ____ of gland
what Ab?

Answer 24

hypothyroidism, chronic lymph thyroiditis, Ab lead to dec thyroid hormone production and destruction of gland
TPO test Ab

Question 25

Describe nuclear medicine eval
what is the acronym
low uptake
high uptake?

Answer 25

radioactive idodine uptake (RAIU)
Low uptake suggests gland is metab. inactive
high uptake suggests met. active prod slight amounts of thyroid hormone

Question 26

Describe Thyroid Ultrasound

Answer 26

high frequency sound waves to thyroid gland, non-palpable nodules

Question 27

Describe fine needle respiration

Answer 27

FNA biopsy first step and most accurate, prompt ID/treatment

Question 28

Describe Hypothyroidism
TSH
FT4
genders/ages
sympt

Answer 28

Low FT4 with norm/high TSH
common, women over 65
low body temp, yellow, hair loss

Question 29

Primary hypothyroidism
2
3

Answer 29

p: hashimotos (anti-TPO)
treat goiter
excessive iodine intake

2- hypopitu
3 - hypothal dysfunct

Question 30

Describe Thyrotoxicosis
peripheral tissues with
excess
I
L
G h

Answer 30

periph tissues present w/ excess thryoid hormone
result of excess thyhroid ingestion, leakage from follicles, excessive gland hormone production

Question 31

Describe hyperthyroidism
autoim activates?
15% have ….
symptoms?

Answer 31

graves, Autoimune activates TSHR, 15% close relative, goiter, orange peel skin, radioactive iodine/meds

Question 32

Describe toxic adenoma/multinodular goiter
what kind of dysfunction
autonom…no what is needed
radioactive iodine does what?

Answer 32

hyperthyroidism, poss. palpable nodules
autonomously func. thyroid issue - no TSH needed
radioactive iodine tends to KILL hyperacitve nodule/leaves in tissue

Question 33

Drug induced thyroid dysfunction
Amio…
37% MW is?

Answer 33

Amiodarone - thryoid diease
cardiac arrythmias 37% MW is iodine

Question 34

Describe Subacute thyroiditis
assoc with…..
most common form?
gender?

Answer 34

assoc. w/ inflam of thyroid, leakage, repair of gland
post partum thyroidtiis most common form .5-9% women

Question 35

Describe nonthyroidal illness and thyroid nodules
TSH/FT4/FT3
what is common
kinds of pts?

Answer 35

critically ill/hospitalized pts low TSH, Low T3 low FT4
nodules common
less than 10% are cancer