Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Pharmacology > Thyroid and Antithyroid Agents > Flashcards

Thyroid and Antithyroid Agents Flashcards

(62 cards)

Start Studying
1
Q

In which species is hypothyroidism most common?

A

Dog (and horse)

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

In which species is hyperthyroidism most common?

A

Cat

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

What is the most prevalent form of hypothyroidism?

A

Lymphocytic thyroiditis

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

What type of process is lymphocytic thyroiditis?

A

Autoimmune

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

What are the clinical signs associated with hypothyroidism?

A

Lethargy, weakness, coma, obesity, cold intolerance, skin lesions (myxedema), alopecia, infertility

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

What is the #2 underlying cause of demodicosis?

A

Hypothyroidism

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

What are the clinical signs associated with hyperthyroidism in a cat?

A

Weight loss, polyphagia, PU/PD, heat intolerance, tachycardia, tachypnea, hair loss, diarrhea, vomiting

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

1 MIT + 1 DIT = ?

A

T3

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

DIT + DIT = ?

A

T4

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

Where is thyroglobulin synthesized?

A

Follicular cells

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

In dogs, ____% of T4 and T3 are bound by plasma proteins.

A

99%

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

Plasma protein binding of T4 and T3 in the dog is greater than or less than that in the human?

A

Less than

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

What are the 3 plasma proteins that bind thyroid hormone?

A
  1. Thyroxin-binding globulin
  2. Transthyretin
  3. Albumin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

In which species is thyroxin-binding globulin NOT found?

A

Cat

Rabbit

Rodent

Bird

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

Place the following in order of the most protein-bound T4 to the least: ruminants, horses, primates, dogs.

A

Primates > ruminants > horses > dogs

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

The more thyroid hormone bound to plasma protein, the longer its half life. What are the half lives of T4 and T3 in the dog?

A

T4 = 8 - 16 hours

T3 = 5 - 6 hours

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

What is the T4 dosage in a dog?

A

> 20 uL / kg / day

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

What is the T4 dosage in a human?

A

50 - 150 uL / day

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

How does estrogen affect TBG synthesis?

A

Increases TBG synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How does liver/kidney disease affect thyroid hormone T1/2?

A

Decrease in plasma protein levels –> decreases T1/2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

____% of T4 –> T3

A

30 - 40%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

____% of T4 –> rT3

A

50%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How are the conjugates of the hormones excreted from the body?

A

Conjugates enter bile –> gut –> feces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the 3 enzymes involved in deiodination?

A
  1. Type 1 deiodinase
  2. Type 2 deiodinase
  3. Type 3 deiodinase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Which of the thyroid hormones are formed by Type 1 deiodinase?
T3 and rT3
26
Which of the thyroid hormones are formed by Type 2 deiodinase?
T3
27
Which of the thyroid hormones are formed by Type 3 deiodinase?
rT3
28
Where is Type 1 deiodinase found?
Liver and kidney
29
Where is Type 2 deiodinase found?
Brain (pituitary) and brown fat
30
Where is Type 3 deiodinase found?
Brain and placenta
31
Rate of T4 --> T3 increases or decreases with hypothyroidism?
Increases
32
Rate of T4 --> T3 increases or decreases with hyperthyroidism?
Decreases
33
____, a glycoprotein hormone, stimulates all steps involved in T4 synthesis.
TSH
34
TSH receptors are coupled to Gs, leading to ____ ____.
cAMP formation
35
cAMP --> ____ --> ____ --> increased protein
cAMP --> PKA-CREB --> increased mRNA --> increased protein
36
____ is needed for synthesis.
Iodide
37
T3 is ___ - ___ times as active as T4.
3 - 5X
38
What are the 3 main components of thyroid hormone's calorigenic actions?
1. Increased heat generation 2. Increased O2 consumption 3. Increased basal metabolic rate
39
Where is brown fat found within the body?
Between scapulas Thorax Abdomen
40
Brown fat cells contain large numbers of what?
Mitochondria
41
Brown fat cells contain large numbers of mitochondria with ____ ____ to generate heat.
Uncoupling proteins
42
Complete the pathway: Cold body temperature --> _____ --> ______ --> Increased T4
Cold body temperature --> Increased TRH --> Increased TSH --> Increased T4
43
Complete the pathway: Cold body temperature --> _____ --> ______ --> Increased T3 --> Increased thermogenin in mitochondria
Cold body temperature --> Increased Epi, NE --> Increased type II deiodinase --> increase T3 --> Increased thermogenin in mitochondria
44
What are the 4 cardiovascular effects of thyroid hormone?
1. Increased CO 2. Increased O2 consumption 3. Increased expression of alpha-1 and beta receptors 4. Increased expression of alpha-myosin heavy chain and Ca2+ channels in the myocardium
45
Would you expect a high or low cholesterol level in a hypothyroid patient? Why?
High cholesterol - thyroid hormones increase the conversion of cholesterol into bile acids
46
Thyroid hormone is needed for skin and hair turnover. What would be the dermatologic effects of hyperthyroidism?
Alopecia
47
Thyroid hormone is needed for skin and hair turnover. What would be the dermatologic effects of hypothyroidism?
Thickened skin (myxedema)
48
What is the effect of thyroid hormones on GH secretion?
Increases GH secretion & action
49
Thyroid hormones are critical for the development and maintenance of _____ tissue.
Neural
50
In which tissues do you see calorigenesis due to thyroid hormones?
1. Heart 2. Skeletal muscle 3. Liver 4. Kidney
51
Where is irisin found?
Within the skeletal muscle
52
What is the function of irisin?
Converts white fat cells (FCs) into brown fat cells (BFCs)
53
How would hypothyroidism affect keratin and sebum production?
Both would be increased
54
What are the neuromuscular effects of thyroid hormones?
Increase synthesis of proteins associated with neuromuscular activity
55
What are the neuromuscular consequences of hypothyroidism?
1. Myopathy 2. Cranial nerve VII paralysis 3. Cranial nerve VIII paralysis 4. CNS depression
56
What is the MOA of methimazole?
Blocks iodination and coupling reactions
57
Methimazole is 10x more potent than what?
Propylthiouracil (PTU)
58
Which of the following causes hemolytic anemia: Methimazole or Propylthiouracil?
Propylthiouracil (PTU)
59
Which of the following has less side effects: PTU or Methimazole?
Methimazole
60
What are the advantages of topical Methimazole?
1. Convenience | 2. Less GI disturbance (4%)
61
What are the disadvantages of topical Methimazole?
1. Human hazard | 2. Inconsistent absorption
62
What is the half-life of sodium idodide 131?
8 days

Pharmacology (21 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions