S.No.

Subject:

Yorker

1.

Physiology

Question: What is Ondine’s curse?

Answer: The concept is that voluntary and autonomic controls of respiration are separate; and autonomic control is sometimes disrupted without loss of voluntary control. The clinical condition that results has been called Ondine’s curse. In German legend, Ondine was a water nymph who had an unfaithful mortal lover. The king of water nymphs punished the lover by causing a curse upon him that took away all his autonomic functions. In this state, he could stay alive only by staying awake and remembering to breathe. He eventually fell asleep from sheer exhaustion, and his respiration stopped. Patients with this intriguing condition generally have bulbar poliomyelitis or disease process that compresses the medulla. The condition has also been produced inadvertently in patients who have been subjected to bilateral anterolateral cordotomy for pain. This cuts away the pathways that bring about autonomic respiration while leaving the various efferent pathways in the corticospinal and rubrospinal tracts intact.

 Source:  Review of Medical Physiology by William F. Ganong. Sixteenth Edition.

2.

Pharmacology

Question: What is inverse agonist?

Answer: Some substances produce effects that are specifically opposite to those of agonist. The agonist action of benzodiazepines on the benzodiazepine receptor in CNS causes sedation, anxiolysis, muscle relaxation and control convulsions; however substances called, “B-carbolines” bind to same receptor and cause stimulation, anxiety, increased muscle tone and convulsions. Such substances are called inverse agonists. In this case, both act by modulating the effects of GABA. 

Source: Clinical Pharmacology by D.R. Laurence, P.N. Bennett Seventh Edition.