LT Review Q's Flashcards
Where does ADH act?
at the target site of the cortical collecting duct of the kidney
What does the protein aquaporin 2 (AQP2) do?
forms a channel that carries water molecules across cell membranes
diabetes incipidus is more likely to be aquired by which sex?
males (60%)
Which of the following is due to a defect in the thirst control mechanism?
a. nephrogenic diabetes insipidus
b. neurogenic diabetes insipidus
c. dipsogenic diabetes insipidus
d. gestational diabetes insipidus
c. dipsogenic diabetes insipidus
Which of the following usually resolves?
a. nephrogenic diabetes insipidus
b. neurogenic diabetes insipidus
c. dipsogenic diabetes insipidus
d. gestational diabetes insipidus
d. gestational diabetes insipidus
Which of the following is due to ADH resistance?
a. nephrogenic diabetes insipidus
b. neurogenic diabetes insipidus
c. dipsogenic diabetes insipidus
d. gestational diabetes insipidus
a. nephrogenic diabetes insipidus
Which of the following can occur due to head trauma?
a. nephrogenic diabetes insipidus
b. neurogenic diabetes insipidus
c. dipsogenic diabetes insipidus
d. gestational diabetes insipidus
b. neurogenic diabetes insipidus
trauma affecting the pituitary gland
Which of the following occurs due to interference with protein aquaporin 2 (AQP2)?
a. nephrogenic diabetes insipidus
b. neurogenic diabetes insipidus
c. dipsogenic diabetes insipidus
d. gestational diabetes insipidus
a. nephrogenic diabetes insipidus
A patient presents with polyuria and polydipsia. Which one of the following diagnostic tests would NOT suggest a diagnosis of central or pituitary diabetes insipidus?
A. Low urine osmolality and high plasma osmolality
B. High plasma sodium
C. increased urine osmolality after administration of ADH in a water deprivation test
D. low urine osmolality after administration of ADH in a water deprivation test
E. High plasma osmolality and low ADH
D. low urine osmolality after administration of ADH in a water deprivation test
Which of the following features are relevant to Addison’s disease?
A. Immunological destruction of adrenal medullar cells
B. Increased production of cortisol
C. Increased production of aldosterone
D. Immunological destruction of steroid cells in the adrenal cortex
E. Increased growth of adrenal cortex cells
D. Immunological destruction of steroid cells in the adrenal cortex
What percent of Addison’s disease are autoimmune in origin?
75-80% of the cases are autoimmune in origin
What two hormones are low in Addison’s disease?
cortisol and aldosterone
The majority of Addison’s disease is due to which autoimmune condition?
autoimmune adrenalitis
What two body antigens are targeted in Addison’s disease?
21-alpha-hydroxylase corticotrophin receptors (autoantibodies against them)
infiltrating lymphocytes are available when adrenal damage is mediated by
a. autoantibodies
b. cell-mediated immunity
b. both
b. both
Which is located extra-adrenally?
a. Pheochromocytoma
b. Paragangliomas
b. Paragangliomas
Which enzyme is indicative of Pheochromocytoma?
Phenylethanolamine N-methyltransferase (PNMT)
Which is the most common symptom of Pheochromocytoma?
a. pulmonary edema
b. cardiomyopathy
c. hypertension
c. hypertension
T/F: the hypertension of Pheochromocytoma is only dependant upon the amount of catecholamines in circulation
false, it depends on many other factors (their diffusion rate, rate of inactivation, smooth muscle reactivity, receptor sensitivity/number, renin, etc.)
What’s the function of Phenylethanolamine N-methyltransferase (PNMT) enzyme?
converts norepinephrine to epinephrine
How can you differentiate if the hypertension of Pheochromocytoma is due to excess renin? (what drug do you use?)
By seeing the effect of Captopril on hypertension. Captopril is an angiotensin-converting enzyme inhibitor (ACE inhibitor)
(if it helped then renin was the issue)
How could you differentiate between a patient with pheochromocytoma or one with essential hypertension?
plasma atrial natriuretic peptide and adrenomedullin levels increase in pheochromocytoma patients only
What is true in patients who got pheochromocytoma due to a hereditary familial disorder?
a. no hypertension symptoms
b. bilateral tumors
c. affects men four times as much
b. bilateral tumors
Whats the only reliable clue to suggest pheochromocytoma malignancy?
metastases
What four syndromes are associated with pheochromocytoma?
Multiple Endocrine Neoplasia, type 2A (MEN2A)
Multiple Endocrine Neoplasia, Type 2B (MEN2B)
Von Hippel-Lindau disease (VHL)
Neurofibromatosis type 1 (NF1)
Describe the headache of patients with essential hypertension
occipital, not temporal
Where are pheochromocytoma found?
a. biochemical phase
b. prebiochemical phase
a. biochemical phase
diagnosis is established by the biochemical confirmation of catecholamine hypersecretion
After pheochromocytoma presence is confirmed, what tests do you run?
tomography scan (CT scan) & magnetic resonance imaging (MRI)
(after catecholamine hypersecretion is confirmed, do imaging studies)
Which is most commonly used for preoperative control of blood pressure?
a. α- adrenoceptor blocker
b. β-adrenoceptor blocker
a. α- adrenoceptor blocker
pheochromocytoma presence is confirmed but MRI is negative, which test do you do next?
a. tomography scan (CT scan)
b. MIBG scintigraphy
b. MIBG scintigraphy
MIBG (metaiodobenzylguanidine) scans help locate and diagnose certain types of tumors in the body because it gathers in some tumors. When combined with radioactive iodine (tracer), it provides a way to identify primary and metastatic disease.
Where are incidentaloma found?
a. biochemical phase
b. prebiochemical phase
b. prebiochemical phase
Which is most commonly used for preoperative control of arrhythmias, tachycardia or angina?
a. α- adrenoceptor blocker
b. β-adrenoceptor blocker
b. β-adrenoceptor blocker
Pheochromocytoma are:
a. Neuroendocrine tumours of the adrenal cortex
b. More common in women compared with men
c. The cause of hypertension in about 0.2% of hypertensive subjects
d. Always malignant
e. Never inherited
c. The cause of hypertension in about 0.2% of hypertensive subjects
β-adrenoceptor blockers should never be employed without… (explain why?)
blocking α-adrenoceptor mediated vasoconstriction
(β-adrenoceptor cause vasodilation to balance out the vasoconstriction of α-adrenoceptor. If you block β-adrenoceptors alone, the vasoconstriction will be unbalanced and cause high BP)
How do you treat pheochromocytomas?
surgical excision (laparoscopy is the first choice)
What is the most common cause of hypothyroidism in developed countries?
a. Autoimmune thyroiditis
b. Hypothalamic and pituitary disorders
c. Iodine deficiency
d. Congenital disorders
e. Postpartum thyroiditis
a. Autoimmune thyroiditis
hashimotos
What percent of women acquire postpartum thyroiditis?
versus
What percent of women who have anti-thyroid antibodies acquire postpartum thyroiditis?
5%
50%
Which of the following methods of preventing thyroid diseases is not justified?
a. providing adequate iodine intake
b. Screening for congenital hypothyroidism
c. Screening for subclinical hypothyroidism and hyperthyroidism in adults
c. Screening for subclinical hypothyroidism and hyperthyroidism in adults