This set of Molecular Endocrinology Multiple Choice Questions & Answers (MCQs) focuses on “Female Reproductive Axis Physiology & Pathology”.
1. What is the most common disorder of fluid and electrolyte balance encountered in hospitalized patients?
a) Hypoosmolality
b) Hyperosmolality
c) Hypertension
d) Hypotension
View Answer
Explanation: Hypoosmolality is the most common fluid and electrolyte balance condition encountered in patients who are hospitalized. The occurrence and prevalence of hypo osmolar disorders depend on the characteristics of the studied patient population and the procedures and criteria used for the diagnosis of hyponatremia in the laboratory.
2. Which among the following is a situation in which hyponatremia does not reflect true hypoosmolality?
a) Pseudo hypoosmolality
b) Pseudohyponatremia
c) Pseudo hypernatremia
d) Pseudohypooligoria
View Answer
Explanation: There are two situations in which true hypoosmolality does not represent hyponatremia. Pseudohyponatremia, produced by marked elevations in plasma of either lipids or proteins, is the first. Pseudohyponatremia is a rare laboratory abnormality characterized by a serum sodium concentration of less than 135 mEq/L (280 to 300 mOsm/kg) at the level of normal serum osmolality.
3. Which among the following signifies total-body solute depletion?
a) Hypoalgesia
b) Hyponatremia
c) Hypovolemia
d) Hypoosmolality
View Answer
Explanation: Clinically measurable hypovolemia often means loss of total-body solute. Low urine [Na+] is indicative of a non-renal cause and a suitable renal response. Hypovolemia is a reduction in the body’s blood flow, which may be attributed to lack of blood or body fluids.
4. SIADH is produced when plasma levels of arginine vasopressin are elevated.
a) True
b) False
View Answer
Explanation: SIADH is developed when arginine vasopressin plasma levels are elevated at times when the physiological secretion of vasopressin from the posterior pituitary is typically suppressed. The clinical abnormality is a drop in the osmotic pressure of body fluids, so hypoosmolality is the hallmark of SIADH.
5. Solutes that readily permeate cell membranes (e.g., urea, ethanol, methanol) are effective solutes.
a) True
b) False
View Answer
Explanation: Solutes that permeate cell membranes easily (e.g., urea, ethanol, methanol) are not effective solutes. Therefore, to ascertain whether clinically significant hyperosmolality or hypoosmolality is present, only the concentrations of effective solutes in plasma should be used.
6. Which is the most common cause of renal solute losses?
a) Therapy with Chloramphenicol
b) Therapy with thiazide diuretics
c) Therapy with Allopurinol
d) Therapy with bromothymol blue
View Answer
Explanation: The most common cause of renal solution loss is therapy with thiazide diuretics, especially in the elderly. But mineralocorticoid deficiency caused by adrenal insufficiency or resistance to mineralocorticoids must also be considered.
7. SIADH is the most common cause of which among the following disorders?
a) Euvolemic hypoosmolality
b) Hydrophobic hypoosmolality
c) Hydrogenic hyperosmolality
d) Rhythmic hyperosmolality
View Answer
Explanation: The most common cause of Euvolemic hypoosmolality is SIADH. And it is also the most popular cause of hypoosmolality in clinical practice among all etiologies encountered. Inappropriate antidiuretic hormone secretion (SIADH) syndrome is a condition in which too much antidiuretic hormone is released by the body (ADH).
8. Which disease is depicted in the graph given below which shows the plasma arginine vasopressin levels?
a) Hypovolemia
b) Hyponatreuretism
c) Hypoosmolality
d) SIADH
View Answer
Explanation: Plasma arginine vasopressin (AVP) levels in patients with inappropriate antidiuretic hormone secretion (SIADH) syndrome as a function of plasma osmolality are shown in this graph. At a single point in time, each point portrays one patient.
9. Which among the following is the most common association of SIADH?
a) Tumors
b) Kidney stones
c) Diabetes Insipidus
d) Diabetes Mellitus
View Answer
Explanation: SIADH is most often associated with tumors. Many different forms of tumors have been associated with SIADH, but since the first mention of this condition in1957, bronchogenic lung carcinoma has been specifically associated with SIADH.
10. In humans, which among the following is more associated with abnormal water retention?
a) Hypervolemia
b) Hypercarbia
c) Hypovolemia
d) Serotonemia
View Answer
Explanation: Hypoxia facilitates vasopressin secretion in mammals, but hypercarbia is more associated with excessive water retention in humans. When respiratory failure is most severe, elevated vasopressin may be limited to the initial days of hospitalization.
11. In patients with SIADH which condition likely explains the failure to find expanded plasma or ECF volumes?
a) Secondary natriuresis
b) Primary natriuresis
c) Hypoosmolality
d) Hypovolemia
View Answer
Explanation: The inability to detect expanded plasma or ECF volumes using tracer dilution techniques is possibly explained by secondary natriuresis in patients with SIADH. Long-term antidiuretic-induced hyponatremia experiments in dogs and rat have shown that a significant proportion of hyponatremia is due to secondary loss of Na+.
12. Who proposed Cerebral salt-wasting syndrome for the first time?
a) Peters and associates
b) Franklin and Amlin
c) Sanger and Gilbert
d) Milovan and Oswald
View Answer
Explanation: In1950, Peters and associates proposed Cerebral salt-wasting syndrome. This is an explanation for the intracranial disease that sometimes accompanies natriuresis and hyponatremia, particularly subarachnoid hemorrhage, in which hyponatremia develops in up to one-third of patients.
13. Vasopressin stimulates water retention by increasing the activity and abundance of which among the following aquaporins?
a) Aquaporin 2
b) Aquaporin 3
c) Aquaporin 7
d) Aquaporin 9
View Answer
Explanation: By increasing the activity and abundance of aquaporin-2 water channels in the renal collecting duct epithelium, vasopressin stimulates water retention. Chronic vasopressin stimulation in SIADH produces dramatic increases in aquaporin 2 content and insertion into the epithelial cell membranes beyond normal levels.
14. Hypoosmolality is primarily associated with a broad spectrum of which among the following conditions?
a) Neurologic manifestations
b) Endocrine manifestations
c) Articular manifestations
d) Muscular manifestations
View Answer
Explanation: Hypoosmolality is mainly associated with a wide variety of neurological manifestations, ranging from mild, non-specific symptoms (e.g., headache, nausea) to severe disorders (e.g., disorientation, confusion, obtundation, neurological focal deficiencies, seizures). This neurologic symptom complex has been defined as hyponatremic encephalopathy.
15. What are the Antagonists of the kidney vasopressin V2 receptors called?
a) Vaptans
b) Haptens
c) Epitopes
d) Paratopes
View Answer
Explanation: Kidney vasopressin V2 receptor antagonists are called vaptans. In the treatment of patients with dilutional hyponatremia, they are the ideal agent. Aquaresis, that is, solute-free urinary excretion, is caused by them.
Sanfoundry Global Education & Learning Series – Molecular Endocrinology.
To practice all areas of Molecular Endocrinology, here is complete set of 1000+ Multiple Choice Questions and Answers.