Difference Between Auricle and Ventricle

Main Difference – Auricle vs Ventricle

The heart is the muscular pump of blood in the animals with a closed circulatory system. In a closed circulatory system, the blood circulates through the heart and blood vessels. Auricle and ventricle are two anatomical structures of the heart. Auricle refers to the upper chambers of the heart in lower animals such as mollusks. In mammals such as humans, the auricle refers to an appendage of the atrium. Ventricle refers to the lower chambers of the heart. The main difference between auricle and ventricle is that auricle aids the collection of blood into the heart whereas ventricle pumps blood to the corresponding parts of the body with a high pressure.

Key Areas Covered

1. What is Auricle
– Definition, Structure, Function
2. What is Ventricle
– Definition, Structure, Function
3. What are the Similarities Between Auricle and Ventricle
– Outline of Common Features
4. What is the Difference Between Auricle and Ventricle
– Comparison of Key Differences

Key Terms: Atrium, Auricle, Heart, Mollusks, Pulmonary Circulation, Systemic Circulation, Ventricle

What is Auricle

Auricle refers to a structure of the atrium of the heart, resembling an earlobe. The mammalian heart consists of two atria as right atrium and left atrium. An auricle is attached to the anterior surface of the outer wall of each atrium. Thus, two auricles present in the heart. It can be visualized as a wrinkled, flap-shape structures on top of the heart. The main function of the auricle is to increase the capacity of the atrium. The auricles are anatomically important as other structures of the heart. The auricles of the human heart are shown in figure 1.

Difference Between Auricle and Ventricle

Figure 1: Auricles

Auricle is also used as another term for the atrium of mollusks. The phylum Mollusca consists of an open circulatory system where blood is not completely circulated inside blood vessels. Therefore, the tissues of mollusks are bathed in the hemolymph during the exchange of nutrients and gases. The heart of mollusks consists of three chambers: two upper chambers known as auricles and a single ventricle.

What is Ventricle

Ventricle refers to the two lower chambers of the heart. Ventricles are more muscular than the atria or auricles of the heart. Hence, they have thicker walls as well. The main function of ventricles is to pump blood to the corresponding parts of the body with a high pressure. The more muscular walls of the ventricles help to increase the pressure of blood. Some invertebrates have a single ventricle in their heart while most vertebrates have two chambers in their heart as right ventricle and left ventricle. The anatomy of the right and left ventricles is shown in figure 2.

Figure 2: Ventricles

The presence of two ventricles facilitates the double circulation of animals. The two types of circulation mechanisms involved in double circulation are the systemic circulation and pulmonary circulation. The oxygenated blood is transported to the metabolizing tissues of the body during systemic circulation and the deoxygenated blood from the tissues return to the right atrium of the heart. The left ventricle is involved in the pumping of blood to the body in the systemic circulation. The deoxygenated blood is then transported to the lungs to take up oxygen from the atmospheric air during the pulmonary circulation and the reoxygenated blood return to the left atrium of the heart. The right ventricle is involved in pumping blood to the lungs in the pulmonary circulation.

Similarities Between Auricle and Ventricle

Auricle and ventricle are two anatomical structures of the heart.
Both auricle and ventricle are involved in pumping blood to the corresponding parts of the body.

Definition

Auricle: Auricle refers to a structure of the atrium of the heart, resembling an earlobe.

Ventricle: Ventricle refers to the two lower chambers of the heart.

In Mollusks

Auricle: The auricle is the upper chambers of the heart in mollusks.

Ventricle: The ventricle is the lower chamber of the heart in mollusks.

In Humans

Auricle: The auricle is the wrinkled, flap-shape structure of the atrium.

Ventricle: Humans have two ventricles as the lower chambers of the heart.

Structure

Auricle: The auricle is less muscular or consists of a thin wall.

Ventricle: The ventricle is more muscular than the auricle.

Significance

Auricle: The auricle helps to collect blood from the body.

Ventricle: Ventricles pump blood to the corresponding parts of the body.

Conclusion

Auricle and ventricle are two anatomical structures of the heart. Auricle is the upper chamber of the heart of lower animals while the wrinkled, flap-shape structure of the atrium of humans is also known as the auricle. Auricle helps to collect blood from the body into the heart. But, the ventricle is the lower chambers of the heart, pumping blood to the corresponding parts of the body. The main difference between auricle and ventricle is their structure and the function of each type in the circulation of blood.

Reference:

1. “Auricle of the heart.”, IvyRose Holistic, Available here.
2. “Phylum Mollusca.” THE CIRCULATORY SYSTEM, Available here.
3. “Double Circulation.” Double Circulatory Systems, Available here.

Image Courtesy:

1. “Anatomy Heart English Tiesworks” By Tvanbr – Own work (Public Domain) via Commons Wikimedia
2. “2007 Ventricular Muscle Thickness” By OpenStax College – Anatomy & Physiology, Connexions Web site, Jun 19, 2013 (CC BY 3.0) via Commons Wikimedia