What is the Difference Between Sinus Venosus and Conus Arteriosus?

The sinus venosus and conus arteriosus are two distinct structures in the heart, serving different functions and having unique characteristics:

Sinus Venosus:

• It is a quadrangular, thin-walled pouch located just before the right atrium.
• Its primary function is to collect venous blood from all the body's organs.
• In many fish species, it serves as a pacemaker.
• The structure is made up of connective tissues, with an inner lining of endothelial cells and outer epicardial walls.

Conus Arteriosus:

• It is a conical pouch formed in the right ventricle.
• The conus arteriosus is the site from where the pulmonary artery arises.
• Its primary function is to facilitate the flow of blood from the right ventricle to the pulmonary artery.
• In frogs, the conus arteriosus has a spiral valve that helps in regulating the flow of blood.

In summary, the sinus venosus is a quadrangular pouch that collects venous blood and may function as a pacemaker in some species, while the conus arteriosus is a conical pouch that facilitates blood flow from the right ventricle to the pulmonary artery.

Comparative Table: Sinus Venosus vs Conus Arteriosus

The sinus venosus and conus arteriosus are two structures in the heart with distinct differences. Here is a table comparing their characteristics:

The sinus venosus is primarily responsible for collecting venous blood from various organs and delivering it to the atrium, while the conus arteriosus facilitates blood flow from the right ventricle to the pulmonary arteries.