7 Questions
What is the primary mechanism by which stimulation of beta-adrenergic receptors increases calcium inside cardiac myocytes?
Phosphorylation of L-type Ca++ channel in the sarcolemma
Which of the following drugs increases Ca++ entry in cardiac myocytes by inhibiting Na+-K+ ATPase in the sarcolemma?
Digitalis
What is the effect of xanthines like caffeine on c-AMP concentration in cardiac myocytes?
Increases c-AMP concentration
Which negative inotropic mechanism is primarily due to insufficient blood supply to cardiac muscle?
Hypoxia
How do glucagon hormones affect c-AMP levels in cardiac myocytes?
Increase c-AMP levels
Which process occurs when Protein Kinase A phosphorylates Ry-calcium release channels on the sarcoplasmic reticulum in cardiac myocytes?
Increased release of Ca++ from SR
Which drug inhibits the breakdown of c-AMP, leading to increased c-AMP concentration inside cardiac myocytes?
Caffeine
This quiz covers the positive inotropic mechanisms involved in the regulation of contractility of cardiac myocytes, focusing on the role of c-AMP and calcium. Topics include stimulation of beta-adrenergic receptors, formation of c-AMP, activation of Protein Kinase A, and the increase of intracellular calcium levels.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
