---
title: "Posterior Interventricular Sulcus | Anatomy I"
description: "Posterior interventricular sulcus is the groove on the back of the heart between the ventricles, carrying coronary vessels in Anatomy and Physiology I."
canonical: "https://fiveable.me/anatomy-physiology/key-terms/posterior-interventricular-sulcus"
type: "key-term"
subject: "Anatomy and Physiology I"
unit: "Unit 19"
---

# Posterior Interventricular Sulcus | Anatomy I

## Definition

The posterior interventricular sulcus is a groove on the posterior surface of the heart that separates the right and left ventricles. In Anatomy and Physiology I, it is a landmark for the vessels that run along the heart muscle.

## What It Is

The posterior interventricular sulcus is the groove on the back of the heart where the right and left ventricles meet. In Anatomy and Physiology I, you use it as a surface landmark, not just a name to memorize, because it tells you where major vessels and chambers are located on the heart model or diagram.

If you picture the heart from behind, this sulcus runs down toward the apex in the line between the ventricles. It is called a sulcus because it is a furrow or groove on an organ surface. The ventricles form most of the heart’s lower, thicker pumping chambers, so a groove between them helps mark that boundary on the exterior even though the chambers themselves are internal.

This groove matters because the heart is not a smooth lump of muscle. Its surface has ridges and grooves that map onto deeper anatomy. The posterior interventricular sulcus usually contains the posterior interventricular artery and the middle cardiac vein, which travel in the coronary circulation and serve the heart muscle itself. If you are tracing blood flow on a lab practical, the groove helps you find where those vessels run.

A common mistake is mixing it up with the anterior interventricular sulcus. Both are grooves between the ventricles, but they are on different sides of the heart. The anterior interventricular sulcus is on the front surface, while the posterior interventricular sulcus is on the back. That difference matters when you are identifying structures on models, specimens, or diagrams.

You will usually see this term while studying heart anatomy alongside the ventricles, coronary vessels, and the external landmarks that help orient the heart. It is a small structure, but it gives you a map of where the ventricles separate and where blood vessels travel to supply the myocardium.

## Why It Matters

The posterior interventricular sulcus shows how surface anatomy connects to the heart’s internal layout. In Anatomy and Physiology I, you do not just memorize that the heart has ventricles, you learn how those chambers are organized and where external landmarks point to them.

This term also helps you trace coronary circulation. Since the sulcus carries vessels that supply the myocardium, it gives you a clue about how blood reaches the heart muscle itself. That connection matters when you are learning why blocked coronary arteries can damage cardiac tissue or why vessel location is so important in anatomy labs.

It also sharpens your visual identification skills. On a heart model, the posterior side can be harder to orient than the front, so knowing this groove helps you tell which surface you are looking at and how the ventricles are arranged. That kind of orientation is a big part of success in A&P, especially on labeling quizzes and practicals.

Finally, it fits into the larger idea that form matches function. The heart’s grooves are not random marks, they reflect the way the chambers and vessels are organized to move blood efficiently through the pulmonary and systemic circuits.

## Connections

### Ventricles

The posterior interventricular sulcus marks the boundary between the right and left ventricles on the heart’s surface. When you identify the ventricles, you are also learning where the heart’s main pumping chambers sit and how their position creates external grooves. This makes the sulcus easier to place on diagrams and models.

### [Coronary arteries](/anatomy-physiology/key-terms/coronary-arteries)

Coronary arteries run along surface grooves, including the posterior interventricular sulcus, to deliver oxygenated blood to the myocardium. This term connects anatomy with function because the groove is not just a landmark, it is part of the route the heart’s own blood supply takes across the surface of the organ.

### Anterior interventricular sulcus

This is the closest comparison term, and it is easy to confuse with the posterior interventricular sulcus. Both are grooves between the ventricles, but one is on the front and one is on the back. If you can place the anterior groove first, the posterior one becomes much easier to identify.

### anterior cardiac veins

Anterior cardiac veins drain blood from the front of the right ventricle, so they show up on the opposite side of the heart from the posterior interventricular sulcus. Comparing them helps you separate structures by surface location, which is useful when you are labeling vessels and grooves on heart diagrams.

## On the AP Exam

A heart diagram question may ask you to identify the posterior interventricular sulcus by locating the groove on the back of the heart between the ventricles. On a lab practical, you might need to point out that it sits near the path of coronary vessels rather than naming a chamber itself. In a short-answer item, you could be asked why that groove matters, and the best response is that it marks ventricular boundaries and provides a route for blood vessels that supply the myocardium. If the question compares front and back views, use the sulcus to orient the specimen and distinguish it from the anterior interventricular sulcus.

## posterior interventricular sulcus vs anterior interventricular sulcus

These two grooves are commonly confused because both lie between the ventricles and both carry coronary vessels. The difference is location: the posterior interventricular sulcus is on the back of the heart, while the anterior interventricular sulcus is on the front. If you know which surface you are viewing, the two are easier to separate.

## Key Takeaways

- The posterior interventricular sulcus is a groove on the back of the heart between the right and left ventricles.
- It is a surface landmark, so it helps you orient the heart when you are looking at a model, diagram, or specimen.
- This groove carries coronary vessels that supply the myocardium, connecting the surface anatomy to heart function.
- It is easy to confuse with the anterior interventricular sulcus, but the two are on opposite sides of the heart.
- In Anatomy and Physiology I, this term shows up when you trace heart anatomy, identify vessels, or label cardiac structures.

## FAQs

### What is posterior interventricular sulcus in Anatomy and Physiology I?

It is the groove on the posterior surface of the heart that separates the right and left ventricles. In A&P I, you use it as a landmark to orient the back of the heart and locate vessels that run in that groove.

### What structures run in the posterior interventricular sulcus?

The posterior interventricular artery and the middle cardiac vein are commonly associated with this groove. Those vessels are part of the coronary circulation, so the sulcus is both a landmark and a pathway for blood supply and drainage on the heart’s surface.

### How is the posterior interventricular sulcus different from the anterior interventricular sulcus?

They are both grooves between the ventricles, but they are on different surfaces of the heart. The posterior interventricular sulcus is on the back, while the anterior interventricular sulcus is on the front. That makes surface orientation the easiest way to tell them apart.

### Why do we learn heart sulci in Anatomy and Physiology I?

Because the grooves help you map the outside of the heart to the chambers and vessels underneath. They come up on diagrams, lab practicals, and any assignment where you have to identify coronary anatomy or explain how the heart is organized.

## Related Study Guides

- [19.1 Heart Anatomy ](/anatomy-physiology/unit-19/1-heart-anatomy/study-guide/rkGmPKJ0SjTIT3Kf)

## About This Document

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