Lecture 4 Short Answer Biochem
26 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the clinical presentation of a 2-week old girl with 11 beta hydroxylase deficiency?

FTT, virilization/Ambiguous genitalia, hypertension

What is the serum level of 17-(OH)-progesterone in the 2-week old girl with 11 beta hydroxylase deficiency?

700

Will renin be elevated in the 2-week old girl with 11 beta hydroxylase deficiency?

No

What are the factors that stimulate aldosterone secretion?

<p>Angiotensin II, K+, Intracellular Ca2+</p> Signup and view all the answers

What is the prevalence of hyperaldosteronism in hypertensives?

<p>Approximately 7%</p> Signup and view all the answers

Is primary hyperaldosteronism a common cause of low plasma potassium?

<p>No</p> Signup and view all the answers

What would you expect the urine potassium to be in a patient with an adrenal tumor?

<p>High</p> Signup and view all the answers

What is Liddle's syndrome?

<p>Liddle's syndrome is a form of pseudohyperaldosteronism characterized by hypertension, low aldosterone and renin levels, and a response to triamterene.</p> Signup and view all the answers

What is the name of the condition caused by the resultant ÇACTH?

<p>Congenital Adrenal Hyperplasia (CAH)</p> Signup and view all the answers

What is the most common enzyme defect in CAH?

<p>21 hydroxylase</p> Signup and view all the answers

What are the effects of CAH on cortisol synthesis?

<p>Cortisol may be maintained by ÇACTH secretion, if partial block. May not be able to respond to stress.</p> Signup and view all the answers

What are the effects of CAH on aldosterone synthesis?

<p>In most cases, there is a smaller effect on aldosterone synthesis. If severe, renal Na+ loss. Aggravated by progesterone &amp;17OH-progesterone which promote salt loss.</p> Signup and view all the answers

What are the primary causes of hyperaldosteronism?

<p>Conn's syndrome, Familial hyperaldosteronism, Glucocorticoid remediable</p> Signup and view all the answers

What are the secondary causes of hyperaldosteronism?

<p>Decreased circulating volume, Diuretic therapy, Renovascular hypertension, Bartter's syndrome</p> Signup and view all the answers

How can primary hyperaldosteronism be diagnosed?

<p>By considering blood pressure, plasma K+ and HCO3-, plasma aldosterone and renin, and aldosterone/renin ratio</p> Signup and view all the answers

How do the biochemical findings differ between primary and secondary hyperaldosteronism?

<p>In primary hyperaldosteronism, plasma renin is low and aldosterone/renin ratio is high, while in secondary hyperaldosteronism, plasma renin is high and aldosterone/renin ratio is low</p> Signup and view all the answers

What are the symptoms of Addison's disease?

<p>Low blood pressure, poor eating habits, feeling unwell</p> Signup and view all the answers

What are the normal reference intervals for U&Es (Sodium, Potassium, Bicarbonate, Urea, Creatinine)?

<p>Sodium: 135-145 mmol/L, Potassium: 3.0-5.0 mmol/L, Bicarbonate: 22-32 mmol/L, Urea: 3-8 mmol/L, Creatinine: 50-120 umol/L</p> Signup and view all the answers

How does aldosterone imbalance affect plasma Na+, K+, and HCO3- levels?

<p>In excess: ↑ plasma Na+/water, ↓ plasma K+, ↑ plasma HCO3- (metabolic alkalosis). In deficiency: ↓ plasma Na+/water, ↑ plasma K+, ↓ plasma HCO3- (metabolic acidosis)</p> Signup and view all the answers

What is the primary stimulus for aldosterone secretion?

<p>Low circulating volume, particularly through the kidneys</p> Signup and view all the answers

What is the purpose of supine/erect aldosterone measurement?

<p>To measure aldosterone levels when supine and after 4 hours of ambulation.</p> Signup and view all the answers

What is the role of adrenal vein sampling in diagnosing primary hyperaldosteronism?

<p>Adrenal vein sampling is used to differentiate between IAH and adrenal adenoma/carcinoma/UAH. In adenomas/carcinomas, the affected gland will have increased aldosterone levels, while the contralateral gland will be suppressed.</p> Signup and view all the answers

What is the cause of Familial Hyperaldosteronism type I?

<p>Familial Hyperaldosteronism type I is caused by unequal crossing over between the CYP11B1 and CYP11B2 genes, which are both located on chromosome 8. This condition can also be diagnosed by the administration of glucocorticoids or PCR based techniques.</p> Signup and view all the answers

What is Conns syndrome?

<p>Conn's syndrome is a condition characterized by the overproduction of the hormone aldosterone by the adrenal glands, leading to excessive sodium reabsorption and potassium excretion in the kidneys. This results in high blood pressure and electrolyte imbalances.</p> Signup and view all the answers

What are the causes of primary hyperaldosteronism and how would you differentiate between primary and secondary hyperaldosteronism?

<p>Primary hyperaldosteronism is most commonly caused by an adrenal adenoma or bilateral adrenal hyperplasia. Secondary hyperaldosteronism, on the other hand, is usually due to an underlying condition such as renal artery stenosis or heart failure. To differentiate between primary and secondary hyperaldosteronism, a plasma aldosterone to renin ratio (ARR) test is performed. A high ARR suggests primary hyperaldosteronism, while a low ARR suggests secondary hyperaldosteronism.</p> Signup and view all the answers

What is Addison's disease and its metabolic consequences on water, glucose, and electrolyte balance?

<p>Addison's disease, also known as primary adrenal insufficiency, is a condition characterized by the inadequate production of adrenal hormones, including aldosterone. This leads to a deficiency in sodium reabsorption and potassium excretion in the kidneys, resulting in electrolyte imbalances. Additionally, Addison's disease can also cause decreased glucose levels and impaired water balance due to the reduced production of cortisol and aldosterone.</p> Signup and view all the answers

More Like This

Use Quizgecko on...
Browser
Open
Browser
Browser