These are specialized tissues found in the heart and digestive system that can generate their own electrical impulses, causing them to contract rhythmically without external stimulation.
Here are some examples of structures with autorhythmic tissues:
* Heart:
* Sinoatrial (SA) node: The primary pacemaker of the heart, located in the right atrium. It initiates the electrical signal that triggers heartbeats.
* Atrioventricular (AV) node: Located at the junction between the atria and ventricles, it delays the electrical signal, ensuring the atria contract before the ventricles.
* Digestive system:
* Pacemaker cells: Found in the walls of the stomach and intestines, they control the rhythmic contractions of the muscles responsible for moving food through the digestive tract.
It's important to note that while these tissues are capable of self-excitation, their rhythm can be influenced by external factors like hormones, neurotransmitters, and the autonomic nervous system.
