2017 · Q25
The mammalian heart is myogenic and it is regulated by nerves. The heartbeat originates from
General KnowledgeBiology
- Asinoatrial node
- BQRS wave
- CT wave
- Dhepatic portal system
Explanation
The heartbeat originates in the sinoatrial (SA) node in the right atrium — the heart's natural pacemaker — which is why the mammalian heart is myogenic. The QRS complex and T wave are ECG features, not origins, and the hepatic portal system carries blood to the liver. Hence A.