Thyroid (week 9)

Question 1

what does the thyroid secrete

Answer 1

thyroid hormone (T3, T4)
parathyroid hormone
calcitonin

Question 2

what hormones secreted by the thyroid are involved in calcium balance

Answer 2

parathyroid hormone

calcitonin

Question 3

what is calcium involved in in the body

Answer 3

nerve and muscle activity

Question 4

precursors for thyroid hormone

Answer 4

monoiodotyrosine (MIT)

diiodotyrosine (DIT)

Question 5

how is T4 formed

Answer 5

two DIT combine

Question 6

how is T3 formed

Answer 6

one MIT and one DIT

Question 7

how will thyroid hormone affect ability to exercise

Answer 7

too low or high levels of T3 and T4 can affect nerve and muscle function

Question 8

effects of thyroid hormone

Answer 8

• necessary for development
• increases fat, protein, and glucose metabolism
• increases body temp

Question 9

permissive hormone

Answer 9

a hormone that does not have a direct effect on tissue, but must be present for normal cell fxn

Question 10

examples of permissive hormones

Answer 10

T3

T4

Question 11

how does the body respond to sympathetic stimulation (norepinephrine) when T3&4 are in excess

Answer 11

excessive response

Question 12

thyrotoxicosis

Answer 12

condition in which thyroid hormones are elevated inapproptiately

Question 13

possible causes of thyrotoxicosis

Answer 13

1. intrinsic influences, such as elevated TSH

2. extrinsic influences, such as ingesting thyroid hormone inappropriately

Question 14

causes of goiter

Answer 14

• overstimulation of thyroid gland*
  1. low iodine intake (overworks thyroid)
  2. increased TSH

Question 15

symptoms of thyrotoxicosis

Answer 15

• increased metabolism
• heat intolerance
• sensitivity to sympathetic stim
• goiter

Question 16

Grave’s Disease

Answer 16

autoimmune disorder where antibodies overstimulate thyroid tissue, rather than destroy tissue

Question 17

most common cause of hyperthyroidism and thyrotoxicosis

Answer 17

Grave’s Disease

Question 18

LATS

Answer 18

Long Acting Thyroid Stimulator

• appear in the blood with Grave’s Disease
• thyroid stimulating antibodies

Question 19

symptoms of Grave’s Disease

Answer 19

ongoing thyrotoxicosis
unexplained weight loss
night sweats
fluctuating BP
mood changes
exopthalamos

Question 20

exopthalamos

Answer 20

“bug eyes”

occurs due to excessive weight loss around eyes

Question 21

thyrotoxic crisis AKA

Answer 21

thyroid storm

Question 22

thyrotoxic crisis symptoms

Answer 22

hyperthermia
tachycardia
delirium
high output cardiac failure (heart can’t keep up with demands)

Question 23

cause of thyrotoxic crisis

Answer 23

Graves Disease left untreated

Question 24

treatment for thyrotoxic crisis

Answer 24

remove thyroid
radioactive iodine
propylthiouacil

Question 25

what is radioactive iodine used for in stopping thyroid storm

Answer 25

destroy some thyroid tissue to decrease output of T3 T4

Question 26

what does propylthiouracil do

Answer 26

blocks synthesis of thyroid hormone

Question 27

how is propylthiouracil ideally administered

Answer 27

if thyroid storm caught in time, drug is titrated (T3 T4 monitored and dosage adjusted based on levels of T3 T4 in blood)

Question 28

primary hypothyroidism

Answer 28

inflammation of the thyroid

Question 29

causes of primary hypothyroidism

Answer 29

``` acute thyroiditis subacute thyroiditis autoimmune thyroiditis irradiation of thyroid iodine deficiency surgical removal of thyroid Lithium ```

Question 30

acute thyroiditis cause

Answer 30

rare; usually due to bacterial infection of thyroid

Question 31

subacute thyroiditis cause

Answer 31

nonbacterial infection of thyroid, often preceded by viral infection

Question 32

autoimmune thyroiditis cause

Answer 32

autoimmune attack of thyroid tissue | acute thyroiditis can lead to autoimmune thyroiditis

Question 33

subacute thyroiditis duration

Answer 33

2-4 months

Question 34

treatment of subacute thyroiditis

Answer 34

corticosteroids

Question 35

secondary hypothyroidism caused by

Answer 35

pituitary dysfunction/hypofunction

Question 36

symptoms of hypothyroidism

Answer 36

- decreased energy, metabolism, heat production - cold intolerance - lethargy - fatigue - myxedemia - hair texture change (more course)

Question 37

myxedemia

Answer 37

AKA boggy edema; swelling where you can push your finger into it and leave an imprint that stays for a few minutes; usually occurs around eyes

Question 38

Congenital Hypothyroidism (Cretinism)

Answer 38

absence of thyroid tissue at birth

Question 39

incidence of cretinism

Answer 39

1 in 4000 live births

Question 40

effects of cretinism if left untreated

Answer 40

mental retardation/developmental delay | stunted skeletal growth

Question 41

treatment for Cretinism

Answer 41

hormone replacement therapy (synthroid) | highly effective if treatment initiated by 3-4 months of age; child can function completely normally with treatment