The crista terminalis or terminal crest represents the junction between the
sinus venosus
The sinus venosus is a large quadrangular cavity which precedes the atrium on the venous side of the chordate heart. In mammals, it exists distinctly only in the embryonic heart, where it is found between the two venae cavae. However, the sinus v ...
and the
heart
The heart is a muscular Organ (biology), organ in most animals. This organ pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxygen and nutrients to the body, while carrying metabolic waste such as ca ...
in the developing
embryo
An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male spe ...
.
In the development of the human heart, the right horn and transverse portion of the sinus venosus ultimately become incorporated with and forms a part of the adult
right atrium
The atrium ( la, ātrium, , entry hall) is one of two upper chambers in the heart that receives blood from the circulatory system. The blood in the atria is pumped into the heart ventricles through the atrioventricular valves.
There are two at ...
,
where it is known as the ''
sinus venarum
The sinus venarum (also known as the sinus of the vena cava, or sinus venarum cavarum) is the portion of the right atrium in the adult human heart where the inner surface of the right atrium is smooth. The sinus venarum represents the portion of t ...
''. The line of union between the right atrium and the
right atrial appendage
The atrium ( la, ātrium, , entry hall) is one of two upper chambers in the heart that receives blood from the circulatory system. The blood in the atria is pumped into the heart ventricles through the atrioventricular valves.
There are two at ...
is present on the interior of the
atrium
Atrium may refer to:
Anatomy
* Atrium (heart), an anatomical structure of the heart
* Atrium, the genital structure next to the genital aperture in the reproductive system of gastropods
* Atrium of the ventricular system of the brain
* Pulmona ...
in the form of a vertical crest, known as the crista terminalis or ''crista terminalis of
His''.
The crista terminalis is generally a smooth-surfaced, thick portion of heart muscle in a crescent shape at the opening into the right atrial appendage. On the external aspect of the right atrium, corresponding to the crista terminalis is a groove, the
terminal sulcus. The crista terminalis provides the origin for the
pectinate muscles
The pectinate muscles (musculi pectinati) are parallel muscular ridges in the walls of the atria of the heart.
Structure
Behind the crest ( crista terminalis) of the right atrium the internal surface is smooth. Pectinate muscles make up the pa ...
.
See also
*
Sinoatrial node
The sinoatrial node (also known as the sinuatrial node, SA node or sinus node) is an oval shaped region of special cardiac muscle in the upper back wall of the right atrium made up of cells known as pacemaker cells. The sinus node is approxima ...
References
External links
* - "Heart: Chamber of Right Atrium"
* - "Right atrium, internal structure, anterior view"
Diagram at ctsnet.org
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Heart