Skip to content
EasyAnatomyLab
Menu

Wall of atrium: anatomy, location and function

The muscular walls of the right and left atria, the thin-walled receiving chambers of the heart. The atria receive returning blood and, by contracting at the end of diastole, top up ventricular filling.

Loading 3D model…
Skin0%
Muscles100%

Structures

Loading… Click the model or search.

Highlighted in the model: Wall of atrium. Click any part to read about it, or switch off “Highlight topic” to see the whole body. 3D data: BodyParts3D, © The Database Center for Life Science, CC BY 4.0; meshes simplified and recoloured. The model is an adult male.

Wall of atrium at a glance

What it is
The muscular walls of the right and left atria, the thin-walled receiving chambers of the heart.
Location
The right atrial wall has a rough anterior part with pectinate muscles, including the auricle, separated by the crista terminalis from the smooth posterior part (sinus venarum) that receives the venae cavae. The left atrial wall is smooth except in the left auricle and forms most of the base (posterior surface) of the heart.
Function
The atria receive returning blood and, by contracting at the end of diastole, top up ventricular filling.
Body system
Cardiovascular · paired (left and right)
FMA ID
FMA9531 (Foundational Model of Anatomy)

Key facts

  • The sinu-atrial node lies in the right atrial wall near the opening of the superior vena cava, at the top of the crista terminalis.
  • The fossa ovalis in the interatrial septum is the remnant of the fetal foramen ovale.
  • The left atrium lies directly in front of the oesophagus, so an enlarged atrium can indent it.

Clinical relevance

In atrial fibrillation the atria quiver instead of contracting; clots tend to form in the left auricle.

Structures next to the wall of atrium

The nearest named structures in the 3D model, measured from the centre of each part:

References

  1. Foundational Model of Anatomy: Wall of atrium (FMA9531). EMBL-EBI Ontology Lookup Service.
  2. OpenStax. Anatomy and Physiology 2e, §20.1 Structure and Function of Blood Vessels. Rice University, 2022.
  3. Mitsuhashi N. et al. (2009). BodyParts3D: 3D structure database for anatomical concepts. Nucleic Acids Research 37, D782–D785. Data © The Database Center for Life Science, CC BY 4.0.

Explore the whole body in the interactive 3D human anatomy model, or browse the A–Z list of human structures.