Organ
Crista terminalis
Right atrial ridge where pectinate muscles begin
High-yield
The crista separates the smooth sinus venarum from the pectinate region. Its superior portion is close to the sinoatrial node and superior caval junction.
Overview
This muscular ridge curves along the right atrial wall between the caval regions. Pectinate muscles extend from it toward the appendage, while smoother venous wall lies on its other side. The external sulcus terminalis follows the corresponding boundary.
Reference facts
- Location
- Right atrial wall, extending between the superior and inferior caval regions
- Parts
- Curved muscular ridge with pectinate bundles radiating from it; external counterpart is the sulcus terminalis
- Blood supply
- Atrial arterial branches, including supply associated with the variably originating sinoatrial nodal artery
- Innervation
- Autonomic fibers serving right atrial myocardium; specialized nodal tissue lies nearby
- Relations
- Smooth venous atrium posteriorly, pectinate region anteriorly and sinoatrial node near the upper end
- Function
- Defines a muscular boundary between atrial regions and contributes to atrial activation and contraction
Clinical correlation
Focal atrial tachycardia can originate in the crista terminalis. A prominent normal ridge can also resemble a mass on some imaging views, making anatomical recognition useful.
Frequently asked questions
Where is the crista terminalis located?
The crista terminalis lies right atrial wall, extending between the superior and inferior caval regions.
What does the crista terminalis do?
Defines a muscular boundary between atrial regions and contributes to atrial activation and contraction.
What are the parts of the crista terminalis?
Curved muscular ridge with pectinate bundles radiating from it; external counterpart is the sulcus terminalis.
What is the blood supply of the crista terminalis?
The crista terminalis is supplied by the atrial arterial branches, including supply associated with the variably originating sinoatrial nodal artery.