What is the Difference Between Thorax and Thoracic Cavity

What are thorax and thoracic cavity? Do they refer to the same or different? The upper body of humans has two compartments called the thorax and thoracic cavity. Informally, the thorax is the chest, found between the abdomen and the root of the neck. Superior structures of the thorax include the breast, muscles, and skin. The two components of the thorax are the thoracic cavity and the thoracic wall. The thoracic cavity is the space in the thorax. It contains organs such as the heart, lungs, esophagus, trachea, thymus, nerves, and blood vessels. Therefore, it has respiratory, cardiovascular, nervous, immune, and digestive systems. On the other hand, the thoracic wall contains ribs, thoracic vertebrae, sternum, muscles, and cartilage.   

What is the difference between thorax and thoracic cavity? The thorax is the region between the abdomen and the root of the neck, whereas the thoracic cavity is the hollow space in the body enclosed by the ribs, vertebral column, and breastbone.

Key Areas Covered

1. What is Thorax
     – Definition, Facts, Features
2. What is Thoracic Cavity
     – Definition, Facts, Features
3. Similarities Between Thorax and Thoracic Cavity
     – Outline of Common Features
4. Difference Between Thorax and Thoracic Cavity
      – Comparison of Key Differences
5. FAQ – Thorax and Thoracic Cavity
     – Answers to Frequently Asked Questions

Key Terms 

Thoracic Cavity, Thorax

What is Thorax

The thorax or chest is a part of the anatomy of mammals and other animals. It occurs between the abdomen inferiorly and the root of the neck superiorly. The breast, muscles, and skin are the superior structures of the thorax. The thoracic cavity and thoracic wall are the two structures of the thorax.

Figure 1: Thorax

Furthermore, the thoracic wall contains 12 ribs, 12 thoracic vertebrae, sternum, cartilage, and five muscles. Movement, respiration, and protection are the functions of the thoracic cavity. The posterior thoracic wall is composed of thoracic vertebral bodies and intervertebral discs.

What is Thoracic Cavity

The thoracic cavity is the space in the chest containing blood vessels, organs, nerves, and other body structures. The right pleural cavity, left pleural cavity, and mediastinum are the three components of the thoracic cavity. The heart, lungs, esophagus, thymus, and trachea are the five main organs of the thoracic cavity.

Figure 2: Thoracic Cavity

Moreover, the thoracic cavity occurs deep in the thoracic wall, inferior to the root of the neck and superior to the root of the neck. Organs and tissues of the thoracic cavity are responsible for respiratory, cardiovascular, nervous, immune, and digestive.

Similarities Between Thorax and Thoracic Cavity

• The thorax and thoracic cavity are two components of the upper body.
• They contain lungs and are involved in breathing.

Difference Between Thorax and Thoracic Cavity

Definition

• The thorax is the area of the body between the neck and abdomen, while the thoracic cavity refers to a space in your chest that contains organs, blood vessels, nerves, and other important body structures.

Significance

• The thorax is the upper part of the body, while the thoracic cavity contains the lungs and heart.  

Function

• The two components of the thorax include the thoracic wall and thoracic cavity, and the thoracic cavity is responsible for breathing and pumping blood throughout the body.

FAQ: Thorax and Thoracic Cavity

1. What is the difference between the thorax and the thoracic region?

The thorax is the body region that occurs in different types of animals, such as mammals, fish, birds, reptiles, and arthropods. However, the thoracic region is the upper area of the trunk. It occurs between the base of the neck and the diaphragm.

2. What is the difference between the thoracic cage and the thorax?

The thoracic cage forms the thorax portion of the body. It consists of 12 pairs of ribs, coastal cartilage, and a sternum. Also, 12 thoracic vertebrae anchor posteriorly to the 12 thoracic vertebrae. The heart and lungs are the organs protected by the thoracic vertebrae. 

3. What defines the thoracic cavity?

The diaphragm and the rib cage surround the thoracic cavity. It contains the heart, esophagus, lungs, and thymus, the great vessels, and the sympathetic trunk. Two pleural cavities and mediastinum are the three compartments of the thoracic cavity.

4. Is the thorax the chest?

The chest is properly called the thorax. It is the superior part of the trunk located between the neck and the abdomen. It is composed of a thoracic wall and several cavities.

5. What is the main function of the thorax?

Muscles of the upper extremities, pelvis, vertebral column, head, and neck attach to the thorax. Also, the thorax protects the heart, lungs, and viscera.  

References:

1. Kudzinskas A, Callahan AL. Anatomy, Thorax. [Updated 2023 Jul 30]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-
2. “Thoracic Cavity” By Cleveland Clinic

Image Courtesy:

3. “Chest” By Chikumaya – Own Work (CC-BY SA 2.5) via Anatomy tool
4. “Thorax section 3” By Anatomist90 – Own Work (CC-BY SA 3.0) via Commons Wikimedia