Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Surgery > Thyroid > Flashcards

Thyroid Flashcards

1
Q

What is the embryological origin of the thyroid gland?

A

The thyroid gland arises from the primitive foregut around the 3rd week of gestation.

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

What is the thyroglossal duct?

A

An epithelial-lined tube connecting the thyroid gland to the foramen cecum during embryonic development

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

What is a thyroglossal duct cyst?

A

A congenital cervical anomaly resulting from the persistence of the thyroglossal duct

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

What is the treatment for a thyroglossal duct cyst?

A

Sistrunk operation: en bloc cystectomy and excision of the central hyoid bone to minimize recurrence.

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

What is a lingual thyroid?

A

A developmental abnormality where the thyroid gland fails to descend and remains at the base of the tongue.

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

What is ectopic thyroid tissue?

A

Thyroid tissue found outside its normal location

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

What is the pyramidal lobe?

A

A remnant of the thyroglossal duct found in about 50% of individuals

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

What is the normal weight of the thyroid gland?

A

Approximately 20 grams.

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

What is the histological structure of the thyroid gland?

A

The thyroid is divided into lobules containing 20-40 follicles

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

What are thyroid C cells?

A

Also known as parafollicular cells

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

What is the daily iodine requirement for the body?

A

0.1 mg per day.

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

How is iodine metabolized in the body?

A

Iodine is converted to iodide in the stomach and jejunum

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

What are the steps of thyroid hormone synthesis?

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

What is the difference between T3 and T4?

A

T3 is more potent

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

What is the hypothalamic-pituitary-thyroid axis?

A

A regulatory system that controls thyroid hormone secretion via TRH (thyrotropin-releasing hormone) and TSH (thyroid-stimulating hormone).

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

What is the most sensitive test for thyroid function?

A

Serum TSH (normal range: 0.5-5 μU/mL).

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

What are free T4 and free T3?

A

Free T4 (12-28 pmol/L) and Free T3 (3-9 pmol/L) are the physiologically active forms of thyroid hormones.

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

What is the significance of thyroid antibodies?

A

Elevated in 80% of patients with Hashimoto’s thyroiditis.

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

What is the investigation of choice for discrete thyroid swellings?

A

Fine-needle aspiration cytology (FNAC).

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

What is radionuclide thyroid imaging used for?

A

Uses iodine-123 or iodine-131 to identify cold (20% risk of malignancy) and hot nodules (5% risk).

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

What is the purpose of thyroid ultrasound?

A

To distinguish solid from cystic nodules

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

What is a goiter?

A

Any enlargement of the thyroid gland

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

What is endemic goiter?

A

Caused by iodine deficiency

24
Q

What are goitrogens?

A

Substances that interfere with thyroid function

25
What are the clinical features of nontoxic goiter?
Most patients are asymptomatic; large goiters may cause compressive symptoms like dyspnea and dysphagia.
26
What is Pemberton's sign?
Dilated veins over the chest wall due to retrosternal extension of a large goiter
27
What diagnostic tests are used for goiter?
RAI uptake (patchy uptake in multinodular goiter)
28
What are the common causes of hyperthyroidism?
Graves' disease
29
What is the classic triad of Graves' disease?
1. Thyrotoxicosis
30
What causes hyperthyroidism in Graves' disease?
Stimulatory autoantibodies to the TSH receptor
31
What is Graves' ophthalmopathy?
Characterized by exophthalmos
32
What is pretibial myxedema?
A dermopathy in Graves' disease
33
What diagnostic tests confirm Graves' disease?
Suppressed TSH
34
What are the treatment options for Graves' disease?
1. Antithyroid drugs
35
What are the common antithyroid drugs?
Propylthiouracil (PTU) and methimazole
36
What is radioactive iodine therapy (RAI) used for?
Indicated for older patients with small/moderate goiters
37
When is surgical treatment recommended for Graves' disease?
For large goiters
38
What is toxic multinodular goiter?
Hyperthyroidism in older individuals with a history of nontoxic goiter; may present with atrial fibrillation or heart failure.
39
What is toxic adenoma?
Hyperthyroidism caused by a single hyperfunctioning nodule
40
What is thyroid storm?
A life-threatening condition of severe hyperthyroidism with fever
41
How is thyroid storm managed?
ICU care with beta-blockers
42
What is acute (suppurative) thyroiditis?
A rare infection of the thyroid
43
What is subacute thyroiditis?
Likely viral or autoimmune in origin
44
What is Hashimoto's thyroiditis?
An autoimmune disorder causing destruction of thyroid cells
45
What is Riedel's thyroiditis?
A rare condition where thyroid tissue is replaced by fibrous tissue
46
How is Riedel's thyroiditis diagnosed?
Confirmed by open thyroid biopsy
47
How are thyroid hormones transported in the blood?
Thyroid hormones are transported in serum bound to carrier proteins; only 0.02% is free and physiologically active.
48
What is thyroid peroxidase (TPO)?
An enzyme that catalyzes iodide oxidation and iodination of tyrosine residues in thyroid hormone synthesis.
49
How is TSH secretion regulated?
By a negative feedback loop involving T4 and T3.
50
Where does peripheral conversion of T4 to T3 occur?
Primarily in the liver
51
What proteins bind thyroid hormones in the blood?
Thyroxine-binding globulin (TBG)
52
What is the half-life of T3 and T4?
T3 has a half-life of 1 day
53
Which thyroid hormone is more potent?
T3 is 3-4 times more potent than T4 per unit weight.
54
What regulates thyroid hormone synthesis?
Controlled by TSH
55
Where is the majority of the body's iodine stored?
Over 90% of the body's iodine is stored in the thyroid gland.
56
What stimulates thyroid hormone secretion?
TSH

Surgery (16 decks)

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