Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

hlsc 222- midterm 2 > Thyroid > Flashcards

Thyroid Flashcards

1
Q

2 active thyroid hormones

A

1) T3 (synthetic is liothyronine)
2) T4 (synthetic is levothyroxine)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What thyroid hormone is secreted most

A

T4

BUT must T4 is converted to T3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How much T4 and T3 is available in the body

A

only a small amount… much is bound to plasma proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

thyroid hormones are eliminated via

A

hepatic metabolism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

half life of t3 and t4

A

t3 1 day
t4 7 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Thyroid hormone actions

A

1) Stimulation of energy use
2) Stimulation of heart
3) Promotion of growth and development

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How do thyroid hormones produce effect

A

by modulating specific genes (mostly via T3)

T3 penetrates cell
- binds to nuclear receptors
= production of proteins that mediate thyroid hormone effects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Negative feedback of T3/4

A

as the levels increase
feedback to AP to stop TSH production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Goiter

A

when iodine availability decreases
= increase TSH release
= increase thyroid gland to compensate
= GOITER

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

T3/T4 pathway

A

Hypothalamus
TRH
Anterior Pit
TSH
Thyroid T3 and T 4 - neg feed back to AP
Effects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Hypothyroidism

A

mild deficiency of T3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Myxedema

A

severe deficiency of T3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Symptoms of hypothyroidism in adults

A

mild- subtle and go unrecognized

sever: face= pale, skin = cold dry, hair = brittle, loss of hair, HR and temp are lowered, fatigue, intolerance to cold

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Cause hypothyroidism

A

t3 malfunction via chronic autoimmune thyroiditis (HASHIMOTO thyroiditis)

decreased iodine in diet
surgical removal of thyroid
destruction of thyroid by radioactove iodine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

treatment of hypothyroidism

A

thyroid hormones
T4 alone
T4 and T3
(research: no adv. to T4 and T3 over just T3)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

hypothyroidism and pregnancy

A

can result in neuro-psychologic deficits in child

limited to first trimester when fetus unable to produce its own thyroid hormones

if taking supplements before pregnancy usually requires increased dosage during pregnancy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

hypothyroidism in infants

A

usually from failure of thyroid development
or exposure to radioactive iodine in utero

quick treatment development will be normal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

hyperthyroidism types

A

1) graves (exophthalamos)
2) toxic nodular goiter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Graves disease

A

most common cause of excessive thyroid hormone
- women 20-40

20
Q

clinical presentation (thyrotoxicosis)

A
  • raised metabolic rate, increase temp, increased appetite
  • rapid HR, angina, dysrhythmia
    -CNS stimulated
  • weak muscles, atrophy
21
Q

cause of graves disease

A

thyroid stimulating immunoglobulins (TSIs)
- mimic TSH effects on thyroid function

22
Q

Treatment of graves disease

A

1) surgical removal of thyroid tissue

2) radioactive iodine to destroy thyroid tissue (for adults)

3) antithyroid drug (methimazole or propylthiouracil)

23
Q

Toxic Nodular Goiter (Plummer disease) cause

A

thyroid adenoma (benign lesions of thyroid gland)
- enlarged thyroid gland contains small, rounded nodules which produce too much thyroid hormone

24
Q

Toxic Nodular Goiter treatment

A

antithyroid drug- symptoms occur when stopped

surgery, radiation- long term

25
Q

Thyrotoxic Crisis (Thyroid Storm)

A

Life threatening

occurs with severe thyrotoixosis (excessive plasma levels of thyroid hormones)

26
Q

cause thyrotic crisis

A

surgery, infection, sepsis

27
Q

symptoms of thyrotoxic crisis

A

profound hyperthermia, tachycardia, tremor

28
Q

treatment for thyrotoxic crisis

A

high doses of potassium iodine to suppress thyroid hormone release

29
Q

Types of thyroid hormones available as

A

purse synthetic compounds
- more stable, preferred

Extracts of animal thyroid glands

30
Q

Levothyroxine T4

A

synthetic preparation
- drug of choice for hormone replacement

31
Q

pharmacokinetics levothyroxine t4

A

absorption: reduced by food
take 30-60min before breakfast

converted to T3

Half-life: 7 days
- highly protein bound (99.97%)
good: remains stable
bad: requires 1 month to reach steady state (full effect is delayed

32
Q

Therapeutic uses of Levothyroxine

A

all forms hypothyroidism

used to maintain proper thyroid levels post surgery, irradiation, treatment with antithyroid drugs

note: not for weight loss
- dosage required will establish pathological state

33
Q

levothyroxine adverse effects

A

acute OD: thyrotoxicosis
- tachycardia, angina, tremor

34
Q

levothyroxine drug interactions

A

reduce absorption: lots CHECK LIST WHEN NEEDED
- separate by 4 hours

accelerate drugs metabolism: SEVERAL

Warfarin: accelerates degradation of vit K
- enhances warfarin effects

Catecholamines: increase cardiac effects effects–> dysrhythmias

35
Q

Levothyroxine dosage and administration

A

PO mostly x1 day before breakfast

IV: for myxedema coma and pt that cant PO
or 50po/50iv

Measure TSH

duration: for life is best

36
Q

Antithyroid drugs

A

Thioamides

37
Q

Methimazole

A

first line drug for hyperthyroidism

38
Q

methimazole mechanism

A

blocking thyroid hormone SYNTHESIS via
1) prevents oxidation of iodine
2) prevents iodinated tyrosine from coupling

39
Q

Pharmacokinetics

A

PO
- binding is minimal
- readily crosses membrane

half life 10 hours

40
Q

methimazole therapeutic uses

A
  • graves disease
  • adjunct to radiation therapy

-prep for thyroid gland surgery

-thyrotoxic crisis

41
Q

methimazole adverse effects

A

dont use pregnant/ breastfeeding
- neonatal hypothyroidism

agranulocytosis
-neutrophil count less than 100. microlitre of blood)

hypothyroidism

42
Q

Radioactive Iodine/ iodine- 131
half life

A

radioactive decay half-life 8 days
= 56 days less than 1% of dose radioactivity remains

43
Q

Radioactive Iodine/ Iodine 131 Uses

A

Graves disease

  • destroy thyroid tissue

-adv: cheaper than surgery
-disadv: significant delayed hypothyroidism

44
Q

Non radioactive iodine: Lugol Solution

A

5% iodine and 10% potassium
-iodine reduced to iodide in GIL

45
Q

Lugol solution mechanism

A

1) high iodide decreases iodine uptake
2) high iodide inhibit thyroid hormone synthesis

iodide effects cannot be sustained indefinitely/ effects weaken

46
Q

Lugol solution therapeutic uses

A

thyroidectomy patients before surgery to suppress thyroid function

hlsc 222- midterm 2 (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions