https://stream.echo6.co/videos/watch/13a02112-caca-40ee-93b0-74b514dc9824 Official Ninja Nerd Website: https://ninjanerd.org Ninja Nerds! In this cardiovascular physiology lecture, Professor Zach Murphy presents an overview of the extrinsic cardiac conduction system, focusing on how the autonomic nervous system (ANS) modulates heart rate, conduction velocity, and contractility to adapt cardiac output to the body’s changing demands. We begin by breaking down the two key branches of the ANS—the sympathetic and parasympathetic nervous systems—and their innervation of the SA node, AV node, and ventricular myocardium. You’ll learn how sympathetic stimulation via β1-adrenergic receptors increases heart rate, conduction velocity, and contractility. In contrast, parasympathetic stimulation through the vagus nerve and muscarinic M2 receptors slows the heart and prolongs AV nodal delay. This lecture also explores the neurotransmitters and second messenger systems involved—norepinephrine activates cAMP pathways in sympathetic signaling, and acetylcholine reduces cAMP through inhibitory G-protein signaling during parasympathetic tone. Enjoy the lecture and support us below! 🌐 Official Links Website: https://www.ninjanerd.org Podcast: https://podcast.ninjanerd.org Store: https://merch.ninjanerd.org 📱 Social Media https://www.tiktok.com/@ninjanerdlectures https://www.instagram.com/ninjanerdlectures https://www.facebook.com/ninjanerdlectures https://x.com/ninjanerdsci/ https://www.linkedin.com/company/ninja-nerd/ 💬 Join Our Community Discord: https://discord.gg/3srTG4dngW #ninjanerd #heart #extrinsiccardiacconduction Mon, 13 Apr 2026 20:32:50 GMT https://validator.w3.org/feed/docs/rss2.html PeerTube - https://stream.echo6.co https://stream.echo6.co/client/assets/images/icons/icon-512x512.png https://stream.echo6.co/videos/watch/13a02112-caca-40ee-93b0-74b514dc9824 All rights reserved, unless otherwise specified in the terms specified at https://stream.echo6.co/about and potential licenses granted by each content's rightholder.