Week 3 Review Q's Flashcards
anatomy of thyroid gland (1-40) physio of thyroid hormone actions (41-74) pharma of thyroid disorder treatments (75-104) micro immunepathogenesis of autoimmune diseases of the thyroid (105-134) Thyroid hormone synthesis biochem (135-170) (anatomy) LAB/practical (170-172) Clinical skills slides (173-186) seminar biochem (187-211) pathology of thyroid (212-252) patho lab (253-262)
Which vertebra is the thyroid gland in front of?
C5-T1
During thyroid gland enlargement, where does the thyroid move?
inferiorly
What percent of thyroids have a pyramidal lobe?
50%
Whats a levator glandulae thyroideae?
fibrous/fibromuscular band that stretches from the pyramidal lobe to the body of the hyoid bone above
Which fascia surrounds the thyroid?
pretracheal fascia
Patient comes in with swelling in the neck, it can either be lymph or thyroid swelling. How can you determine the diagnosis?
palpate and ask patient to swallow, it it moves then its a thyroid enlargement
What gives rise to the superior thyroid artery?
external carotid artery
What gives arterial supply to the posterior aspect of the thyroid?
inferior thyroid artery
What gives rise to the inferior thyroid artery?
thyrocervical trunk of Subclavian artery
What gives arterial supply to the anterior aspect of the thyroid?
superior thyroid artery
Where does the Inferior thyroid vein drain into?
Brachiocephalic vein
Where does the middle thyroid vein drain into?
internal jugular vein
What controls the secretion of hormones from the thyroid?
TSH
What controls the blood supply to the thyroid?
Superior, middle, and Inferior cervical sympathatic Ganglion (vasculomotor)
Patient does surgery to correct hyperparathyroidism by removing the thyoid gland. After surgery, their voice becomes harsh due to the inactivity of the cricothyroid muscle. which nerve is affected?
a. External laryngeal Nerve
b. Recurrent laryngeal nerve
a. External laryngeal Nerve
both laryngeal nerves cause voice changes when damaged
While trying to remove the superior thyroid which is true?
a. Thyroidectomy should be lateral/away from the gland
b. Thyroidectomy should be close to the gland
b. Thyroidectomy should be close to the gland
What gives arterial supply to the isthmus of the thyroid?
Thyroid ima
While trying to remove the inferior thyroid which is true?
a. Thyroidectomy should be lateral/away from the gland
b. Thyroidectomy should be close to the gland
a. Thyroidectomy should be lateral/away from the gland
Patient does surgery to correct hyperparathyroidism by removing the thyoid gland. After surgery, they complain of excessive dryness of mouth?
a. External laryngeal Nerve
b. Recurrent laryngeal nerve
b. Recurrent laryngeal nerve
mucus membrane supplied by nerve
parafollicular cell secretion is controlled by
blood calcium levels
What two things can be found in epithelial follicles of the thyroid gland?
colloid and thyroglobulin (paler gelatinous protein)
Which cell lines follicles of the thyroid gland?
follicular cells or thyrocytes
Which cell shape lines follicles of the thyroid gland?
inactive gland = surrounded by squamous
active gland = surrounded by columnar or cuboidal
follicular cell secretion is controlled by
TSH
What do C cells secrete?
calcitonin
C cells aka parafollicular cells
Which of the following appears darker under H&E?
a. follicular cells
b. parafollicular cells
a. follicular cells
Which of the following appears larger under H&E?
a. follicular cells
b. parafollicular cells
b. parafollicular cells
What moves iodide to the follicular cell?
Na+/I- symporter
What moves iodide to the colloid?
I-/Cl- transporter aka pendrin
What enzyme transforms iodide to iodine?
thyroperoxidase
in the colloid, one iodine attached to the tyrosine of thyroglobulin. What does this create?
monoiodotyrosine (MIT)
What is produced when a monoiodotyrosine (MIT) and diiodotyrosine (DIT) join together?
triiodothyronine (T3)
What makes it easier to remove the thyroid from the parathyroid?
the thin connective tissue capsule
What two locations is the thyroid derived from?
endoderm and the fifth pharyngeal pouch
in the colloid, two iodines attached to the tyrosine of thyroglobulin. What does this create?
diiodotyrosine (DIT)
What is the origin of parafollicular cells?
they’re from the ultimobranchial body, which is derived from the 5th pharyngeal pouch
Which occurs due to thyroglossal duct remnants?
a. thyroglossal cyst
b. thyroglossal fistula
c. both
c. both
Which is derived from the foramen cecum?
a. follicular cells
b. parafollicular cells
a. follicular cells
Which is open to the surface/skin?
a. thyroglossal cyst
b. thyroglossal fistula
c. both
b. thyroglossal fistula
A patient who recently had his thyroid removed still has T3 and T4 in his circulation. What can explain this?
accessory thyroid glandular tissue
Besides the thyroid glands, where can T3/4 be found?
liver and kidney (1/3)
Which has a faster turnover rate?
a. T3
b. T4
c. both the same
a. T3
10%/day for T4 versus 70%/day for T3
Which buffers acute changes in hormone secretion?
a. T3
b. T4
c. both
b. T4
Which is biologically active?
a. reverse T3
b. T3
c. T4
b. T3
Which is most abundant?
a. reverse T3
b. T3
c. T4
c. T4
Which of the following converts T4 to reverse T3?
a. Deiodinase type 1
b. Deiodinase type 2
c. Deiodinase type 3
d. A&B
c. Deiodinase type 3
benov’s note also had D1
Which enzyme allows iodine to bind to the tyrosine of thyroglobulin?
thyroperoxidase
Describe the concentration of iodine in the plasma versus in the follicular cell
30 times more concentrated in the follicular cell
Which of the following inactivates T4?
a. Deiodinase type 1
b. Deiodinase type 2
c. Deiodinase type 3
d. A&B
c. Deiodinase type 3
Which plasma protein do most thyroid hormones bind to?
Thyroxine binding globulin
Which of the following activates T4?
a. Deiodinase type 1
b. Deiodinase type 2
c. Deiodinase type 3
d. A&B
d. A&B
T4 to T3
Which of the following has more T4 binding to it than T3?
a. albumin
b. thyroxine binding pre-albumin
b. thyroxine binding pre-albumin
Which has a stronger negative inhibition effect?
a. reverse T3
b. T3
c. T4
b. T3
Which of the following has more T3 binding to it than T4?
a. albumin
b. thyroxine binding pre-albumin
a. albumin
Which hormone increases the growth and vascularity of the thyroid gland?
TSH
Iodide salts: Reduces the size and vascularity of hyperplastic thyroid glands
Young patient with low thyroid hormones has abnormally short stature. Explain the mechanism.
thyroid hormones stimulate growth hormone action and other hormones to promote bone formation
Oxygen consumption of which tissues are not sensitive to thyroid hormones and why?
adult brain, testis, and spleen because they lack mitochondrial TH receptors
Patient had a lack of TSH for a long time. What happened to his thyroid?
atrophy
Explain the mechanism behind tremors in hyperthyroidism
TH interact with the sympathetic branch of the ANS; beta-adrenergic receptor stimulation
What two things stimulate pulmonary surfactant formation?
thyroid hormones and fetal adrenal gland
When is the thyroid hormone are anabolic?
when they have a low physiologic amount, they have a protein anabolic effect decreasing nitrogen excretion
Describe thyroid hormone levels in Hashimoto thyroiditis
initially high levels, but as the destruction of follicular tissue occurs it becomes low
Antibodies against which of the following are called anti microsomal antibodies?
a. thyroglobulin
b. thyroid peroxidase
b. thyroid peroxidase (aka anti-peroxidase antibodies)
A low IQ in which of the following is reversible?
a. Infantile hypothyroidism
b. congenital hypothyroidism
a. Infantile hypothyroidism
occurs during childhood; give PTH to reverse it
Which of the following causes carpal tunnel syndrome?
a. hypothyroidism
b. hyperthyroidism
a. hypothyroidism
Which of the following is caused by IgG1 antibodies?
a. Hashimoto thyroiditis
b. Graves disease
b. Graves disease
Which receptor do IgG1 antibodies bind to?
TSH receptors
Which of the following causes pretibial myxoedema?
a. hypothyroidism
b. hyperthyroidism
b. hyperthyroidism
Which of the following causes a bruit or murmur?
a. hypothyroidism
b. hyperthyroidism
b. hyperthyroidism
Which of the following causes menorrhagia?
a. hypothyroidism
b. hyperthyroidism
a. hypothyroidism
Which of the following causes exophthalmos?
a. hypothyroidism
b. hyperthyroidism
b. hyperthyroidism
Which of the following has low TRH?
a. Primary hypothyroidism
b. Pituitary hypothyroidism
c. Hypothalamic hypothyroidism
c. Hypothalamic hypothyroidism
Which of the following has low TSH?
a. Primary hypothyroidism
b. Pituitary hypothyroidism
c. Hypothalamic hypothyroidism
b. Pituitary hypothyroidism
Describe TRH and TSH values in graves disease
both low
What stimulates the transcription of the Na+/I- symporter gene?
TSH
What is required during the iodide to iodine transformation by thyroperoxidase?
H2O2, Hydrogen peroxide
Which of the following causes hypothyroidism?
a. Hashimoto thyroiditis
b. Graves disease
a. Hashimoto thyroiditis
What antipsychosis medication causes hypothyroidism?
lithium
Whats the main way that TSH regulates thyroid function?
Uptake of iodide by follicle cells, by stimulating transcription of the iodide transporter genes
Explain why pregnant women are more prone to hypothyroidism
because they produce antibodies to their own thyroid gland
Which of the following can be taken orally?
a. Levothyroxine
b. Liothyronine
c. Liotrix
d. all of the above
d. all of the above
Which of the following has a fast peak and a short duration?
a. Levothyroxine
b. Liothyronine
c. Liotrix
d. all of the above
b. Liothyronine
A pregnant women (in the last trimester) with low thyroid hormones comes in with high blood pressure that lasted for a week. Whats the possible cause?
hypothyroidism increases the risk of preeclampsia — a condition that causes a significant rise in a woman’s blood pressure during the last three months of pregnancy
Which of the following can be given via IV?
a. Levothyroxine
b. Liothyronine
c. Liotrix
d. all of the above
a. Levothyroxine
Liotrix is a mixture of T3 and T4, but at which ratio?
1:4
What kind of drugs are contraindicated in a patient whos taking thyroid hormones?
Drugs that induce CYP450 enzymes because they can accelerate the metabolism of the thyroid hormones and may decrease their effectiveness.
Which of the following is preferred in Myxoedema coma?
a. Levothyroxine
b. Liothyronine
c. Liotrix
d. all of the above
b. Liothyronine
(Myxedema coma = severe hypothyroidism leading to decreased mental status, hypothermia, and other symptoms related to slowing of function in multiple organs. It is a medical emergency with a high mortality rate.)
How can giving thyroid hormone drugs beneficial in some cancers?
some cancers are TSH-dependent, so giving T3/4 reduces the TSH and helps treat
Which of the following is caused by hyperthyroidism?
a. Hashimoto thyroiditis
b. Graves disease
b. Graves disease
Which of the following causes more frequent bowl movements?
a. hypothyroidism
b. hyperthyroidism
b. hyperthyroidism
How many doses of radioactive iodine is given to treat hyperthyroidism?
one dose
What’s the half-life for radioactive iodine?
8 days
What has a longer half-life?
a. Methimazole
b. Propylthiouracil
c. both
d. neither
a. Methimazole
Which is preferred in Pregnant women?
a. Methimazole
b. Propylthiouracil
c. both
d. neither
b. Propylthiouracil
less likely to cross barriers
Which inhibits the release of preformed thyroid hormone?
a. Methimazole
b. Propylthiouracil
c. both
d. neither
d. neither
Which is mainly used to relief symptoms of hyperthyroidism?
a. Iodide salts
b. Propylthiouracil
c. Propranolol
d. Methimazole
c. Propranolol
Which is used to treat thyroid storms?
a. Iodide salts
b. Propylthiouracil
c. Propranolol
d. Methimazole
a. Iodide salts
transient effects
Which TWO inhibit T4 to T3 conversion?
a. Iodide salts
b. Propylthiouracil
c. Propranolol
d. Methimazole
b. Propylthiouracil
&
c. Propranolol
Which causes a metallic taste in the mouth?
a. Iodide salts
b. Propylthiouracil
c. Propranolol
d. Methimazole
a. Iodide salts
Which TWO cause hypoprothrombinemia?
a. Iodide salts
b. Propylthiouracil
c. Propranolol
d. Methimazole
b. Propylthiouracil
&
d. Methimazole
Which reduces hyperplastic thyroid gland vascularity?
a. Iodide salts
b. Propylthiouracil
c. Propranolol
d. Methimazole
a. Iodide salts
Why do Propylthiouracil & Methimazole need weeks to start working?
because they don’t stop the release of preformed hormones, so in those weeks the body is releasing what it previously made
Which has a lower incidence of side effects?
a. Methimazole
b. Propylthiouracil
a. Methimazole
Which has a possible adverse effect of tongue or larynx swelling?
a. Iodide salts
b. Propylthiouracil
c. Propranolol
d. Methimazole
a. Iodide salts
most autoimmune diseases are
a. monogenic
b. polygenic
b. polygenic
T/F: autoimmune thyroiditis can cause either hypo/hyperthyroidism, but it always has goiter to go along with it
false, yes it causes hypo/hyperthyroidism but it doesn’t have to have a goiter (some are with some are without)
Which of the following suppresses the immune system?
a. IL-23
b. IL-4
c. IL-10
d. IL-15
e. IL-21
f. IL-12
c. IL-10
Which TWO of the following activate Th1?
a. IL-23
b. IL-4
c. IL-10
d. IL-15
e. IL-21
f. IL-12
d. IL-15
&
f. IL-12
What three proteins are targeted by lymphocyte made antibodies in autoimmune thyroiditis?
Thyroid peroxidase
Thyroglobulin
Thyroid-stimulating hormone receptor
Which of the following does graves disease cause?
a. hypothyroidism
b. hyperthyroidism
c. both
b. hyperthyroidism
Which of the following does Hashimoto’s thyroiditis cause?
a. hypothyroidism
b. hyperthyroidism
c. both
c. both
hyper initially and hypo eventually
Which TWO of the following activate Th17?
a. IL-23
b. IL-4
c. IL-10
d. IL-15
e. IL-21
f. IL-12
a. IL-23
&
e. IL-21
Which is NOT a sign of hypothyroidism?
a. periorbital edema
b. infertility
c. paresthesia
d. yellow skin
d. proximal muscle weakness
d. proximal muscle weakness
a symptom of hyper
Which of the following activates Th2?
a. IL-23
b. IL-4
c. IL-10
d. IL-15
e. IL-21
f. IL-12
b. IL-4
Why does Hashimoto’s thyroiditis cause hyperthyroidism initially?
the inflammation breaks down the follicles and releases the hormones
Why do patients with Hashimoto’s thyroiditis have low iodine uptake?
Thyroglobulin & Thyroid peroxidase are targeted by autoantibodies. They function to uptake iodine, so when they’re targeted iodine uptake is affected.
Which of the following thyroid antigens are targeted in Graves disease?
a. Thyroid peroxidase
b. Thyroglobulin
c. Thyroid-stimulating hormone receptor
c. Thyroid-stimulating hormone receptor
Which of the following is Hashimoto’s thyroiditis associated with?
a. toxic goiter
b. lymphocytic infiltration
c. subclinical hyperthyroidism
d. the presence of anti TSH receptors
b. lymphocytic infiltration
she put this Q in class
Which of the following increases TSH by increasing follicle size?
a. Thyroid-stimulating immunoglobulin
b. Thyroid growth immunoglobulin
c. Thyroid binding- inhibiting immunoglobulin
b. Thyroid growth immunoglobulin
Which is Th1 predominated?
a. Grave’s disease
b. Hashimoto’s thyroiditis
c. both
b. Hashimoto’s thyroiditis
Th1= cell mediates immunity
chronic lymphocytic thyroiditis is also called
Hashimoto’s thyroiditis
Which of the following is more likely to be targeted in graves disease?
a. Thyroid growth immunoglobulin
b. Thyroid-stimulating immunoglobulin
c. Thyroid binding- inhibiting immunoglobulin
b. Thyroid-stimulating immunoglobulin
Which has tissue destruction?
a. Grave’s disease
b. Hashimoto’s thyroiditis
c. both
b. Hashimoto’s thyroiditis
What thyroid condition is more common in middle-aged women?
Hashimoto’s thyroiditis
Which has lymphocytic infiltration?
a. Grave’s disease
b. Hashimoto’s thyroiditis
c. both
c. both
Which of the following causes hypothyroidism when attacked?
a. Thyroid-stimulating immunoglobulin
b. Thyroid growth immunoglobulin
c. Thyroid binding- inhibiting immunoglobulin
c. Thyroid binding- inhibiting immunoglobulin
Which is Th2 predominated?
a. Grave’s disease
b. Hashimoto’s thyroiditis
c. both
a. Grave’s disease
Th2= humoral immunity
autoimmune polyendocrine syndrome (APS) is caused by which gene?
AIRE gene
What mechanism defect causes autoimmune polyendocrine syndrome (APS)?
failure of central tolerance
Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome is caused by which gene?
FOXP3
What is deficient in IPEX syndrome?
functional T reg cells
Which gene causes bamboo spine? What disease is this found in?
HLA-B27, ankylosing spondylitis
What do TSHR antibodies cause?
a. hypothyroidism
b. hyperthyroidism
b. hyperthyroidism
graves
The “stare sign” is found in which of the following?
a. Grave’s disease
b. Hashimoto’s thyroiditis
c. both
a. Grave’s disease
How does the Na+/I- symporter gets its power?
the Na+/K+ ATPase is a secondary transporter, the symporter uses the Na concentration generated by it to get iodide into the cell
Where is the Na+/I- symporter located?
a. apical cell membrane
b. basolateral cell membrane
b. basolateral cell membrane
Does pendrin need ATP to get iodide out of the cell and into the lumen?
no, it uses facilitated diffusion
What do you get when you combine a tyrosine, a phenyl ring, and two iodine molecules?
thyroxine (T4)
Which is more heavily regulated?
a. Cl-/I- transporter
b. Na+/I- symporter
b. Na+/I- symporter
What’s the rate-limiting enzyme of protein iodination?
dual oxidase (DUOX)
this enzyme makes H2O2, that is the rate-limiting step of protein iodination
Where is H2O2 made?
a. apical cell membrane
b. basolateral cell membrane
a. apical cell membrane
What two things does the dual oxidase (DUOX) enzyme require to function?
Ca2+ and NADH
Whats the most abundant protein in the thyroid gland?
thyroglobulin
How many tyrosyl residues in a thyroglobulin molecule?
two identical chains with around 132 tyrosyl residues
What does the dual oxidase (DUOX) enzyme do? Where?
make H2O2 at the apical cell membrane
What percent of the tyrosyl residues of thyroglobulin are iodinated?
33%
Transthyretin carries which hormone?
a. T3
b. T4
c. both
b. T4
Albumin carries which hormone?
a. T3
b. T4
c. both
c. both
but more T3 than T4
Which of the following inactivates T3 (by making it into T2)?
a. Deiodinase type 1
b. Deiodinase type 2
c. Deiodinase type 3
d. A&B
c. Deiodinase type 3
Which of the following converts reverse T3 into T2?
a. Deiodinase type 1
b. Deiodinase type 2
c. Deiodinase type 3
d. A&B
d. A&B
T/F: more iodide is formed inside the gland than what enters the cell from the blood daily
true (we recycle so much, that’s why we don’t need that much iodine)
Which of the following removes an I2 molecule from the outer ring?
a. Deiodinase type 1
b. Deiodinase type 2
c. Deiodinase type 3
d. A&B
d. A&B
removing from the outer ring activates
How do you treat congenital goiter?
give large amounts of iodide
this is not congenital hypothyroidism. congenital hypothyroidism is untreatable because the CNS didn’t develop
What happens in D2 expressing cells during adaptation to cold? What mediates this reaction?
stimulation of D2 expression increases local T3 production, resulting in increased saturation of T3 receptors.
This increase can be mediated by norepinephrine (NE) stimulation of β-adrenergic receptors (βARs)
Which enzyme is defective in congenital goiter?
thyroid deiodinase
Which of the following removes an I2 molecule from the inner ring?
a. Deiodinase type 1
b. Deiodinase type 2
c. Deiodinase type 3
d. A&B
c. Deiodinase type 3
removing from the inner ring deactivates
Which causes goiter?
a. Insufficient iodine
b. Excess iodide
a. Insufficient iodine
goiter as an attempt to compensate
Describe the mechanism of Wolff-Chaikoff effect?
Iodopeptide(s) are formed that temporarily inhibit TPO mRNA and protein synthesis and, therefore, thyroglobulin iodination.
It prevents the thyroid from synthesizing large quantities of thyroid hormones. It lasts for few days and then, through the so-called “escape” phenomenon, the organification of intrathyroidal iodide resumes and the normal synthesis of T4 and T3 resumes.
How does TSH stimulate thyroid hormone synthesis?
4 ways
Expression of NIS, TPO, and Thyroglobulin
Generate of H2O2
Formation of T3 relative to T4
Internalization of Tg
When does the thyroid hormones act metabolically and when does it act anabolically?
At higher than normal concentrations -> catabolic
= glycogenolysis, breakdown of muscle proteins, lipolysis, gluconeogenesis and ketone synthesis
At lower than normal concentrations -> anabolic
= glycogenesis and protein synthesis
T/F: thyroid response elements (TREs) bind to specific nucleotide sequences in the genes they regulate when hormones are present
false, They bind whether and regulate whether or not the hormone is present
What is cretinism?
A deficiency of thyroid hormone in infants
homodimers are composed of
two thyroid hormone receptors
heterodimers are composed of
thyroid hormone receptors and other nuclear receptor family members (EX/ retinoic acid receptor (RXR))
T/F: Thyroid hormone receptors bind T3 100 times stronger than T4
false, they bind T3 about 10 times stronger than T4
When does the thyroid hormone receptor (TR) bind with a corepressor complex?
a. Upon binding T3
b. In the absence of T3
b. In the absence of T3
When does the thyroid hormone receptor (TR) bind with a coactivator?
a. Upon binding T3
b. In the absence of T3
a. Upon binding T3
Which mechanism of action contribute to cell structure and its basal metabolic rate and can regulate the proliferation of cells?
a. genomic
b. nongenomic
b. nongenomic
T/F: Gene expression cannot be modulated unless a thyroid hormone receptor goes to the nuclei and directly activates/suppresses it
false, gene expression can be modulated from the cell surface by the hormone, without its entry into the cell.
Whats the calorigenic effect?
modulates the resting metabolic rate (RMR), it also involves stimulation of cellular respiration simultaneously with reduced metabolic efficiency
What two cells make up the parathyroid gland?
principal/chief cells
oxyphil cells
Which is larger and lighter staining?
a. chief cells
b. oxyphil cells
b. oxyphil cells
What’s the difference between exophthalmos and lid retraction?
in exophthalmos, you can see the whites of the eye both on the top and bottom of the eye (due to the anterior bulging of the eye)
in lid retraction, you can only see the whites on the top of the eye
What are four features specific for Grave’s disease only?
goiter with bruit pretibial myxedema finger clubbing vitiligo chemosis corneal ulcer (there are more)
What’s the difference between thyroid thrill and bruit?
Thrill is a vibration accompanying a cardiac or vascular murmur that can be palpated. Bruit is a continuous sound that is heard over the thyroid mass
Which of the following causes loss of lateral eyebrows?
a. hypothyroidism
b. hyperthyroidism
a. hypothyroidism
Which of the following large tongue?
a. hypothyroidism
b. hyperthyroidism
a. hypothyroidism
Which helps evaluate the function of the gland?
a. thyroid scan
b. thyroid uptake
b. thyroid uptake
Which represents a hyperfunctioning region?
a. hot nodule
b. cold nodule
a. hot nodule
Which can damage the cells of the thyroid gland?
a. I-131
b. Tc-99m
c. both
a. I-131
Which is used to diagnose the thyroid gland?
a. I-131
b. Tc-99m
c. both
c. both
Which can be used by the thyroid gland?
a. I-131
b. Tc-99m
c. both
a. I-131
Tc-99m enters then leaves, it cannot be incorporated like I-131 can
Describe the thyroid hormone levels of multinodular goiter over time
hyperthyroidism initially but they eventually settle to a hypothyroid state
Which emits gamma rays?
a. I-131
b. Tc-99m
c. both
c. both
gamma rays=used for imaging
Which emits beta particles?
a. I-131
b. Tc-99m
c. both
a. I-131
beta particles=kills cells
Patient comes in two weeks after a bad cold with high T4 levels. Thyroid uptake tests shows no uptake. What’s the likely diagnosis?
subacute thyroiditis
De Quervain’s
Which of the following is the main activating enzyme
a. Deiodinase type 1
b. Deiodinase type 2
c. Deiodinase type 3
b. Deiodinase type 2
Which of the following is the main inactivating enzyme
a. Deiodinase type 1
b. Deiodinase type 2
c. Deiodinase type 3
c. Deiodinase type 3
Which micronutrient is needed for deiodinase activity?
Selenium, present in the active site of deiodinases
Whats the result of de-iodinating the outer ring of T4?
active T3
Where is most T3 in the body made?
from the deiodination of T4 in peripheral tissues (80%), the rest of the 20% is released from the thyroid
Cold stress increases the expression (50-folds) of which of the following?
a. Deiodinase type 1
b. Deiodinase type 2
c. Deiodinase type 3
b. Deiodinase type 2
Whats the result of de-iodinating the inner ring of T4?
inactive reverse T3
What percent of vital functions depends on T3?
About 30%
Which facultative thermogenesis method uses glycolysis as the main source for heat production?
a. Shivering thermogenesis
b. Non-Shivering thermogenesis
c. both
a. Shivering thermogenesis
Which tissues does futile cycling primarily occur in?
brown/white adipose
brain
muscle
Which catecholamine does cold weather induce to activate futile cycling?
norepinephrine
Whats the most important protein in brown adipose that helps futile cycling?
uncoupling protein 1 (UCP1)
What does the proton pump/gradient produce during futile cycling in brown adipose?
a. ATP
b. heat
b. heat
What two hormones mediate non-shivering thermogenic futile cycling in brown adipose tissue?
T3 and norepinephrine
What does the proton pump/gradient produce during futile cycling in white adipose?
a. ATP
b. heat
a. ATP
ATP synthesis and hydrolysis cycle generates the heat
T/F: T3 causes local hyperthyroidism
true
What are the 4 ways that T3 helps in futile cycling of adipose tissue?
trigger genes to enhance lipolysis
activate adenyl cyclase
increases expression of UCP1
increases expression of beta-adrenergic receptor
Ryanodine receptors facilitate calcium movement…
a. from the cytosol to the sarcoplasmic endoplasmic reticulum
b. from the sarcoplasmic endoplasmic reticulum to the cytosol
b. from the sarcoplasmic endoplasmic reticulum to the cytosol
Futile cycling in muscle generates heat by which method?
ATP hydrolysis
Ca2+ slippage results in the calcium being located in which of the following?
a. cytosol
b. sarcoplasmic endoplasmic reticulum
a. cytosol
SERCA receptors facilitate calcium movement…
a. from the cytosol to the sarcoplasmic endoplasmic reticulum
b. from the sarcoplasmic endoplasmic reticulum to the cytosol
a. from the cytosol to the sarcoplasmic endoplasmic reticulum
Where does the sarcolipin protein bind?
to SECRA receptor
What does the sarcolipin protein inhibit?
a. ATP hydrolysis
b. Ca2+ transport into cytosol
c. Ca2+ transport into sarcoplasmic endoplasmic reticulum
c. Ca2+ transport into sarcoplasmic endoplasmic reticulum
In which of the following does T3 increase ATP consumption to generate heat?
a. white adipose
b. brown adipose
a. white adipose
In which of the following does T3 increase heat production without ATP consumption?
a. white adipose
b. brown adipose
b. brown adipose
T/F: hyperplasia of the thyroid means the hormone demand is being met
false
Around how many thyroid follicles from a lobule?
20-30
Why do we take a fine needle aspiration of the thyroid and not a biopsy?
because it’s highly vascular and we don’t want to risk bleeding
Child patient comes in with the testis misplaced (not in scrotal sac), where are they likely to be found?
in the abdomen, near the kidney (that’s where they develop, then migrate to the sac)
Which of the following causes superior mediastinal compression syndrome?
a. Thyroglossal duct cyst
b. Substernal thyroid
c. Aberrant subhyoid thyroid
d. Lateral aberrant thyroid
b. Substernal thyroid
excessive descent, if it enlarges in causes compression
Which can be mistaken for a swollen lymph node?
a. Thyroglossal duct cyst
b. Substernal thyroid
c. Aberrant subhyoid thyroid
d. Lateral aberrant thyroid
d. Lateral aberrant thyroid
Which of the following is known as Graves disease?
a. Diffuse Toxic Hyperplasia
b. Diffuse Nontoxic Hyperplasia
c. Acute Infective Thyroiditis
d. Subacute Granulomatous Thyroiditis
e. Autoimmune thyroiditis
a. Diffuse Toxic Hyperplasia
Which of the following is known as Hashimotos disease?
a. Diffuse Toxic Hyperplasia
b. Diffuse Nontoxic Hyperplasia
c. Acute Infective Thyroiditis
d. Subacute Granulomatous Thyroiditis
e. Autoimmune thyroiditis
e. Autoimmune thyroiditis
Which of the following is neutrophil filled?
a. Diffuse Toxic Hyperplasia
b. Diffuse Nontoxic Hyperplasia
c. Acute Infective Thyroiditis
d. Subacute Granulomatous Thyroiditis
e. Autoimmune thyroiditis
c. Acute Infective Thyroiditis
Which of the following has aggregations of epithelioid cells and multinucleated giant cells?
a. Diffuse Toxic Hyperplasia
b. Diffuse Nontoxic Hyperplasia
c. Acute Infective Thyroiditis
d. Subacute Granulomatous Thyroiditis
e. Autoimmune thyroiditis
d. Subacute Granulomatous Thyroiditis
Which of the following is dominantly caused by iodine deficiency?
a. Diffuse Toxic Hyperplasia
b. Diffuse Nontoxic Hyperplasia
c. Acute Infective Thyroiditis
d. Subacute Granulomatous Thyroiditis
e. Autoimmune thyroiditis
b. Diffuse Nontoxic Hyperplasia
Why do we see high cases of Diffuse Nontoxic Hyperplasia in Kuwait even though iodine deficiency is very low?
Biosynthesis defect of the thyroid hormone, the iodine is available but it can’t be used.
The cysts found in Diffuse Nontoxic Hyperplasia are composed of which cell type?
a. follicular cells
b. parafollicular cells
c. plasma cells
d. macrophages
a. follicular cells
Describe the colloid levels in Diffuse Nontoxic Hyperplasia
a. no colloid
b. thin colloid
c. plently of colloid
b. thin colloid
Which of the following characteristically causes infiltrative dermopathy and infiltrative ophthalmopathy?
a. Diffuse Toxic Hyperplasia
b. Diffuse Nontoxic Hyperplasia
c. Acute Infective Thyroiditis
d. Subacute Granulomatous Thyroiditis
e. Autoimmune thyroiditis
a. Diffuse Toxic Hyperplasia (Graves Disease)
Which immunoglobulin mediates Diffuse Toxic Hyperplasia?
IgG
Describe the colloid levels in the fine-needle aspiration of Diffuse Toxic Hyperplasia
a. no colloid
b. thin colloid
c. plently of colloid
a. no colloid (in background)
What does papillary structure indicate?
hyperplasia
Describe hormone level changes in a patient with de Quervain’s thyroiditis
Transient hypothyroidism then complete recovery
de Quervain’s thyroiditis=Subacute Granulomatous Thyroiditis
Fine needle aspiration shows Fire-flare appearance (marginal vacuoles), whats the diagnosis?
a. Diffuse Toxic Hyperplasia
b. Diffuse Nontoxic Hyperplasia
c. Acute Infective Thyroiditis
d. Subacute Granulomatous Thyroiditis
e. Autoimmune thyroiditis
a. Diffuse Toxic Hyperplasia
Which of the following has paravacuolar granulations?
a. Diffuse Toxic Hyperplasia
b. Diffuse Nontoxic Hyperplasia
c. Acute Infective Thyroiditis
d. Subacute Granulomatous Thyroiditis
e. Autoimmune thyroiditis
d. Subacute Granulomatous Thyroiditis
What two things does the presence of autoantibodies help us do?
diagnose the disease and help us know how severe it is
Describe Hurthle cell metaplasia. What is it? In what condition does it occur? Why? In which cells does in occur in?
its when the follicular cells transform from one cell type to another. Occurs in Hashimoto’s thyroiditis. Occurs so follicular cells escape the antibodies against them. Benign follicular cells undergo these changes.
Which is the most aggressive/dangerous thyroid tumor?
a. Anaplastic Carcinoma of Thyroid
b. Follicular Adenoma
c. Papillary Thyroid Carcinoma
d. Medullary Thyroid Carcinoma
e. Lymphoma of the Thyroid
f. Follicular Thyroid Carcinoma
a. Anaplastic Carcinoma of Thyroid
Which of the following causes the thyroid to appear muscle-like and without the gelatinous look?
a. Diffuse Toxic Hyperplasia
b. Diffuse Nontoxic Hyperplasia
c. Acute Infective Thyroiditis
d. Subacute Granulomatous Thyroiditis
e. Autoimmune thyroiditis
a. Diffuse Toxic Hyperplasia
Which is the most commonly found in Kuwaiti females?
a. Anaplastic Carcinoma of Thyroid
b. Follicular Adenoma
c. Papillary Thyroid Carcinoma
d. Medullary Thyroid Carcinoma
e. Lymphoma of the Thyroid
f. Follicular Thyroid Carcinoma
c. Papillary Thyroid Carcinoma
Which is likely to metastasize in up to 70% if the cases?
a. Anaplastic Carcinoma of Thyroid
b. Follicular Adenoma
c. Papillary Thyroid Carcinoma
d. Medullary Thyroid Carcinoma
e. Lymphoma of the Thyroid
f. Follicular Thyroid Carcinoma
f. Follicular Thyroid Carcinoma
Which cancers are patients with Hashimoto’s Thyroiditis more susceptible to in the future?
After a certain amount of years they may develop lymphoma or papillary thyroid carcinoma
Which of the following is derived from parafollicular cells or C-cells?
a. Anaplastic Carcinoma of Thyroid
b. Follicular Adenoma
c. Papillary Thyroid Carcinoma
d. Medullary Thyroid Carcinoma
e. Lymphoma of the Thyroid
f. Follicular Thyroid Carcinoma
d. Medullary Thyroid Carcinoma
Should you remove the thyroid in patients with Hashimoto’s Thyroiditis?
no, you don’t remove it because the gland is already failing. If you remove it you’re adding to the problem.
Which has a positive reaction for calcitonin, chromogranin, and apple green birefringence?
a. Anaplastic Carcinoma of Thyroid
b. Follicular Adenoma
c. Papillary Thyroid Carcinoma
d. Medullary Thyroid Carcinoma
e. Lymphoma of the Thyroid
f. Follicular Thyroid Carcinoma
d. Medullary Thyroid Carcinoma
Which is characterized by Intranuclear cytoplasmic inclusions and Psammoma bodies?
a. Anaplastic Carcinoma of Thyroid
b. Follicular Adenoma
c. Papillary Thyroid Carcinoma
d. Medullary Thyroid Carcinoma
e. Lymphoma of the Thyroid
f. Follicular Thyroid Carcinoma
c. Papillary Thyroid Carcinoma
Which of the following has well developed germinal centers?
a. Diffuse Toxic Hyperplasia
b. Diffuse Nontoxic Hyperplasia
c. Acute Infective Thyroiditis
d. Subacute Granulomatous Thyroiditis
e. Autoimmune thyroiditis
e. Autoimmune thyroiditis
Hashimotos
Which is a solitary, spherical, and encapsulated region?
a. Anaplastic Carcinoma of Thyroid
b. Follicular Adenoma
c. Papillary Thyroid Carcinoma
d. Medullary Thyroid Carcinoma
e. Lymphoma of the Thyroid
f. Follicular Thyroid Carcinoma
b. Follicular Adenoma
(OR
f. Follicular Thyroid Carcinoma
we can’t tell the difference without looking for vascular invations)
Which is characterized by Nuclear grooves (aka coffee bean appearance)?
a. Anaplastic Carcinoma of Thyroid
b. Follicular Adenoma
c. Papillary Thyroid Carcinoma
d. Medullary Thyroid Carcinoma
e. Lymphoma of the Thyroid
f. Follicular Thyroid Carcinoma
c. Papillary Thyroid Carcinoma
What differentiates between Follicular Thyroid Adenoma and Carcinoma in a histology sample?
Vascular and capsular invasion (present in carcinoma)
What differentiates between Follicular Thyroid Adenoma and Carcinoma in a fine needle aspirate sample?
you can’t, so they generalize them under the term “follicular neoplasm”
Most cancers have a hyper-chromatic nucleus, Which thyroid cancer has hypo-chromatic/clear nucleus (Orphan Anie nuclei)?
Papillary Thyroid Carcinoma
Which has a strong association with Hashimoto’s thyroiditis?
a. Anaplastic Carcinoma of Thyroid
b. Follicular Adenoma
c. Papillary Thyroid Carcinoma
d. Medullary Thyroid Carcinoma
e. Lymphoma of the Thyroid
f. Follicular Thyroid Carcinoma
e. Lymphoma of the Thyroid
Which of the following is an amyloid-forming tumor?
a. Anaplastic Carcinoma of Thyroid
b. Follicular Adenoma
c. Papillary Thyroid Carcinoma
d. Medullary Thyroid Carcinoma
e. Lymphoma of the Thyroid
f. Follicular Thyroid Carcinoma
d. Medullary Thyroid Carcinoma
Patient comes in with problems swallowing. Fine needle aspirate of thyroid shows plasmacytoid or triangular tumor cells. Which is most likely?
a. Anaplastic Carcinoma of Thyroid
b. Follicular Adenoma
c. Papillary Thyroid Carcinoma
d. Medullary Thyroid Carcinoma
e. Lymphoma of the Thyroid
f. Follicular Thyroid Carcinoma
d. Medullary Thyroid Carcinoma
What are two causes of nontoxic thyroid goiter?
low iodine
increased intake of food that inhibits hormone synthesis (cabbage/cauliflower)
What leads to scalloping out (resorption) of the colloid?
increased activity to produce thyroid hormone (ex/ in graves disease)
What’s the relationship between cholesterol levels and thyroid hormone levels?
inversely proportional, the more thyroid hormone the less the cholesterol
(Your body needs thyroid hormones to make cholesterol and to get rid of the cholesterol it doesn’t need. When thyroid hormone levels are low (hypothyroidism), your body doesn’t break down and remove LDL cholesterol as efficiently as usual. LDL cholesterol can then build up in your blood.)
A patient with Hashimoto’s go this thyroid remove, what is the gross anatomy of that thyroid?
both lobes replaced by fleshy white adipose, they also have a nodular appearance
(FYI: we should NOT remove the thyroid of a Hashimoto’s patient)
Why do patients with hypothyroidism lose the lateral eyebrow hairs?
the thyroid hormone is essential in protein gene transcription, so any deficiency would lead to a decreased/defective hair protein synthesis.
(another note said it’s due to the accumulation of mucopolysaccharides)
(the Dr in the clinical skills also said that it may be lateral hair loss because they sleep on their side a lot, and so the hair would shed, idk if its true 😂)
Whats the most common place for the metastasis of thyroid tumors?
the lungs, liver, and bones
regional lymph nodes rarely involved
Patient has a cold nodule on the thyroid. FNA shows microacinar formation. A biopsy was done and there was no vascular or capsular invasion. Whats the most accurate diagnosis?
a. follicular neoplasm
b. follicular adenoma
c. follicular carcinoma
b. follicular adenoma
Which thyroid cancer is often familial?
medullary carcinoma
What mutation is in papillary thyroid carcinoma?
RET translocation/inversion
BRAF mutation
What mutation is in medullary thyroid carcinoma?
Germline RET mutations
Which of the following is painlful subacute thyroiditis?
a. Thyroiditis due to lymphocytic inflammation
b. Postpartum thyroiditis
c. De Quervain’s thyroiditis
c. De Quervain’s thyroiditis
Describe subclinical hyperthyroidism
low/undetectable TSH and normal T3/4 levels
Why do some hypothyroidism patients develop large tongue, hoarseness of voice, and carpal tunnel syndrome?
accumulation of mucopolysaccharides
The thyroid is removed in a 65kg patient. How many mcg of the hormone does he need to take per day?
104mcg per day
1.6mcg/kg/day
Describe overt hyperthyroidism
low/undetectable TSH and elevated T3/4
Which of the following causes Vocal cord palsy when damaged?
a. Phrenic nerve
b. Recurrent laryngeal nerve
c. Cervical sympathetic chain
d. Jugular veins
b. Recurrent laryngeal nerve
What is the most sensitive screening test for functional disorders of the thyroid?
TSH tests
Which of the following causes Horner’s syndrome when damaged?
a. Phrenic nerve
b. Recurrent laryngeal nerve
c. Cervical sympathetic chain
d. Jugular veins
c. Cervical sympathetic chain
What are the symptoms of Horner’s syndrome?
miosis (constriction of the pupil)
ptosis (drooping of the upper eyelid)
anhidrosis (absence of sweating of the face)
What test do you use to asses thyroid size?
ultrasound
Patient with an enlarged thyroid gland complains of shortness of breath when lying flat (symptom of Diaphragm paralysis). Which nerve is most likely affected?
a. Phrenic nerve
b. Recurrent laryngeal nerve
c. Cervical sympathetic chain
a. Phrenic nerve
When does the thyroid make its descent from the base of the tongue to its the final position?
week 5
Whats the difference between Iodine 123, 127, and 131?
Iodine 123 has a 13 hour half life so its not practical to use for radiotracing
Iodine 127 is the normal iodine thats stable and that the body uses
Iodine 131 is perfect for radiotracing because of its 8 day half life
What’s the best radiotracer? why?
a. Iodine 123
b. Iodine127
c. Iodine 131
d. 99mTcO4
d. 99mTcO4
its cheap and widely available, it also doesn’t emit beta particles and thus no cellular damage is possible
After giving the patient 99mTcO4, how long must you wait before imaging?
20 minutes
While doing an iodine uptake scan, you see two areas above the thyroid that had some uptake. What is that?
salivary gland (it has some uptake)
Toxic multinodular goitre is also known as
Plummer disease
Which of the following would respond better to iodine 131 treatment? Why?
a. Graves disease
b. Plummer disease
b. Plummer disease
(because the uptake would be localized to the hot nodules and they’d get most of the effect. After the destruction of the hyperactive areas, the rest of the thyroid would resume its normal function and life long hypothyroidism would be less likely)
What’s the highest dose of iodine 131 you can get and still go home afterward? (no hospital admission)
30 mci
What are the precautions patients must abide with once treated with iodine-131?
sleep alone for a week
no contact with kids or pregnant women
What is the only medication the patient can keep taking before the iodine-131 therapy?
beta-blockers
cause vasodialation
Which is most likely to be cancer?
a. cold nodule
b. hot nodule
a. cold nodule
A U-shaped normal gland indicates
a. hypotrophy
b. hypertrophy
b. hypertrophy
How can nuclear medicine help those who got thyroid cancer treated via thyroidectomy?
it can help destroy the remnants, using both methods together has the best outcome
Which parathyroid originated from the third pharyngeal pouch?
inferior
Which cells of the parathyroid secrete PTH?
cheif cells
Which cycling rhythm does the PTH follow?
diurnal rhythm
Which parathyroid originated from the fourth pharyngeal pouch?
superior
Function and mechanism of PTH?
increase serum calcium by stimulates the release of calcium from bones, reduces loss of calcium in the kidney, and indirectly increases calcium absorption from food.
Which causes bone pains and kidney stones?
a. hypoparathyroidism
b. hyperparathyroidism
b. hyperparathyroidism
Whats the function of the parathyroid scan?
a. to diagnose the patient
b. to locate the glands
b. to locate the glands
Whats the most common cause of primary hyperparathyroidism?
adenomas (80%)
During a parathyroid scan, you see that there are delayed imaging. What does this mean?
that there’s hypermetabolic activity
you can even assume adenomas since its the most likely to cause hyperactivity
What radiopharmaceutical do we use to see adrenal activity?
I-131 nor-cholesterol
it uses cholesterol to synthesize the hormones
What does lugol’s solution do?
block the thyroid
While performing cortical scintigraphy, we cannot visualize the uptake of I-131 nor-cholesterol by the adrenals. What does this mean about the adrenals?
a. adenoma
b. hyperplasia of bilateral adenomas
c. normal
c. normal
What do we use for adrenal Medulla Imaging?
123/131 MIBG (metaiodobenzylguanidine)
123/131 MIBG (metaiodobenzylguanidine) is an analog of
norepinephrine
Who most likely gets diagnosed with neuroblastoma?
children younger than 4 years (75%)
While performing cortical scintigraphy, we visualize a unilateral uptake of I-131 nor-cholesterol by the adrenals. What does this mean about the adrenals?
a. adenoma
b. hyperplasia of bilateral adenomas
c. normal
a. adenoma
How many amino acids does somatostatin have?
How many amino acids does PTH have?
14 in somatostatin
84 in PTH
What type of receptor receives somatostatin?
G protein (six G protein coupled receptors)
Where are Somatostatin Receptors located?
Neuroendocrine cells
Activated lymphocytes
Kidneys
Which of the following tumors is more likely to be differentiated?
a. negative SSTR (Somatostatin receptor) expression
b. positive SSTR (Somatostatin receptor) expression
b. positive SSTR expression
SSTR expression more often in well-differentiated tumors
What’s an analog of Somatostatin?
Octreotide
How many amino acids does Octreotide have?
8
Which Somatostatin receptors does Octreotide bind to?
Binds mainly to SSTR-2 and SSTR-5 receptor subtypes
(sstr2»sstr5>sstr3).
Which patients must you take precautions with during In-Octreotide imaging?
insulinoma patients
What’s true about tumors seen on Octreotide?
a. more malignant
b. likely to respond to management
c. have a five-year survival rate of 5%
b. likely to respond to management
have a five-year survival rate of 50%
What is Theranostics Approach?
specific targeted therapy based on specific targeted diagnostic tests (pair a diagnostic method and a treatment)