The crista terminalis generally takes the form of a smooth-surfaced, crescent-shaped thickened portion of heart muscle at the opening into the right atrial appendage.[citation needed] It consists of fibromuscular tissue.[3]
Features
On the external aspect of the right atrium, corresponding to the crista terminalis, is a groove - the terminal sulcus.[citation needed]
The sinoatrial node is located in the superior part of the crista terminalis at the junction of the right atrium, and superior vena cava.[2]: 60
Development
During the development of the human heart, the right horn and transverse portion of the sinus venosus ultimately become incorporated with and form a part of the adult right atrium.[1] The right sinus horn[4] of the sinus venosus develops into the sinus venarum; in the adult right atrium, the portion of right atrium derived from the sinus venosus has a smooth inner surface.[2]: 56
Clinical significance
A prominent crista terminalis may be mistaken for a cardiac mass during heart imaging; a prominent crista terminalis appears as a hyperechoic ridge on echocardiography, and homogenous to adjacent atrial wall on CT and MRI.[3]