Heart Anatomy: Right Atrium Overview

Structure and Functions of the Right Atrium

• Receives venous blood from three major sources: superior vena cava, inferior vena cava, and coronary sinus.
• Has a cuboidal shape that allows effective reception of blood.

Anterior Wall Characteristics

• Composed of rough muscular tissue called pectinate muscles, which increases atrial contractility.
• Features an ear-like conical pouch known as the auricle, which enhances the atrium's volume and overlaps the ascending aorta.

Posterior Wall Overview

• Known as the sinus venarum, it is the smooth, thin-walled section where major venous openings occur.
• Serves as the entry point for poorly oxygenated blood from the superior vena cava, inferior vena cava, and coronary sinus.

Medial and Inferior Wall Details

• The interatrial septum contains an oval depression called the oval fossa, a remnant from fetal development indicating the location of the oval foramen.
• The inferior wall houses the right atrioventricular valve, also known as the tricuspid valve, regulating blood flow to the right ventricle.

Grooves and Ridge Features

• Externally marked by a shallow vertical groove, the sulcus terminalis (terminal groove), which separates smooth and rough wall segments.
• Internally defined by the crista terminalis (terminal crest), a vertical ridge that aids in distinguishing the atrial wall's textures.

Closure Mechanism

• The orifice of the right atrium is closed off by the tricuspid valve, preventing backflow during ventricular contraction.

Structure and Functions of the Right Atrium

• Receives venous blood from three major sources: superior vena cava, inferior vena cava, and coronary sinus.
• Has a cuboidal shape that allows effective reception of blood.

Anterior Wall Characteristics

• Composed of rough muscular tissue called pectinate muscles, which increases atrial contractility.
• Features an ear-like conical pouch known as the auricle, which enhances the atrium's volume and overlaps the ascending aorta.

Posterior Wall Overview

• Known as the sinus venarum, it is the smooth, thin-walled section where major venous openings occur.
• Serves as the entry point for poorly oxygenated blood from the superior vena cava, inferior vena cava, and coronary sinus.

Medial and Inferior Wall Details

• The interatrial septum contains an oval depression called the oval fossa, a remnant from fetal development indicating the location of the oval foramen.
• The inferior wall houses the right atrioventricular valve, also known as the tricuspid valve, regulating blood flow to the right ventricle.

Grooves and Ridge Features

• Externally marked by a shallow vertical groove, the sulcus terminalis (terminal groove), which separates smooth and rough wall segments.
• Internally defined by the crista terminalis (terminal crest), a vertical ridge that aids in distinguishing the atrial wall's textures.

Closure Mechanism

• The orifice of the right atrium is closed off by the tricuspid valve, preventing backflow during ventricular contraction.

Explore the structure and functions of the right atrium, including its walls and the significance of various features. This quiz will test your knowledge on the anatomy, including the pectinate muscles, sinus venarum, and the interatrial septum.