Crista terminalis
The Crista Terminalis represents the junction between the sinus venosus and the heart in the developing embryo. In the development of the human heart
The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...

, the right horn and transverse portion of the sinus venosus
Sinus venosus
The sinus venosus is a large quadrangular cavity which precedes the atrium on the venous side of the chordate heart. In humans, it exists distinctly only in the embryonic heart, where it is found between the two venae cavae...

 ultimately become incorporated with and form a part of the adult right atrium
Right atrium
The right atrium is one of four chambers in the hearts of mammals and archosaurs...

. The line of union between the right atrium and the right auricle is present on the interior of the atrium in the form of a vertical crest, known as the crista terminalis of His (Wilhelm His, Jr.
Wilhelm His, Jr.
Wilhelm His, Jr. was a Swiss-born cardiologist and anatomist.He was born on December 29, 1863 to Wilhelm His, Sr.. In 1893, he discovered the bundle of His, which is a specialized tissue in the heart that transmits the electrical impulses and helps synchronize contraction of the cardiac muscles...

). The crista terminalis is generally a smooth-surfaced, thick portion of heart muscle in a crescent shape at the opening into the right auricle. On the external aspect of the right atrium, corresponding to the crista terminalis is the sulcus terminalis
Terminal sulcus (heart)
The separation of the right atrial pectinate muscle from the sinus venarum is indicated externally by a groove, the terminal sulcus , which extends from the front of the superior vena cava to the front of the inferior vena cava, and represents the line of union of the sinus venosus of the embryo...

. The Crista Terminalis provides the origin for the pectinate muscles.

External links

- "Heart: Chamber of Right Atrium" - "Right atrium, internal structure, anterior view"
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