What is the upper half of the torso called?

October 2, 2025 •

4 min read

The human torso is divided into distinct anatomical regions, with the upper portion housing several of the body's most vital organs. Knowing what is the upper half of the torso called is the first step toward understanding this complex area and the critical functions it performs every moment of every day.

Quick Summary

The upper half of the torso is anatomically known as the thorax or chest, a region that extends from the base of the neck down to the diaphragm and protects essential organs like the heart and lungs.

Key Points

Thorax is the anatomical term: The correct anatomical term for the upper half of the torso, or chest region, is the thorax.
Protects vital organs: The thorax is enclosed by the rib cage and sternum, which serve to protect the heart and lungs.
Separated by the diaphragm: A dome-shaped muscle called the diaphragm separates the thorax from the lower torso, or abdomen.
Houses major systems: Key components of the respiratory and circulatory systems, including the trachea and major blood vessels, are located within the thoracic cavity.
Composed of bones and muscles: The thorax is a complex region featuring the ribs, sternum, and thoracic vertebrae, supported by numerous muscles that aid in breathing and movement.
Critical for health: The health of the thorax is crucial for overall well-being, as it contains organs essential for life, making its protection and function a priority in healthcare.

Delving into the Thorax: Anatomy of the Upper Torso

While the term "chest" is commonly used, the anatomical name for the upper half of the torso is the thorax. This vital region is a hub of biological activity, encased within the protective cage of the ribs and sternum, and separated from the lower torso by the diaphragm. Understanding the intricate components of the thorax is key to grasping the full picture of human physiology and overall health.

The Bony Framework of the Thorax

The structure of the thorax is defined by its bony architecture, known as the thoracic cage. This framework provides protection and support, comprising several key components:

The Ribs: Humans have 12 pairs of ribs. The first seven pairs are considered "true ribs," as they connect directly to the sternum. Ribs 8 through 10 are "false ribs," joining the sternum via the cartilage of the seventh rib. The last two pairs, ribs 11 and 12, are "floating ribs," attached only to the vertebrae.
The Sternum: Often called the breastbone, the sternum is a long, flat bone located in the center of the chest. It is divided into three parts: the manubrium, the body, and the xiphoid process.
The Thoracic Vertebrae: The 12 thoracic vertebrae (T1-T12) form the posterior wall of the thorax and provide attachment points for the ribs. These bones protect the spinal cord and enable the torso's flexibility.

The Thoracic Cavity and its Vital Contents

Within the protective thoracic cage lies the thoracic cavity, a space filled with some of the body's most critical organs and structures. This cavity is further divided by the mediastinum, the central compartment containing the heart and other key structures.

Organs of the Thorax

Heart: The muscular pump responsible for circulating blood throughout the body. It sits within the mediastinum, slightly to the left of center.
Lungs: The primary organs of the respiratory system, located on either side of the heart. They are essential for gas exchange, taking in oxygen and expelling carbon dioxide.
Trachea (Windpipe): The tube connecting the larynx to the bronchi, allowing air to pass to and from the lungs.
Esophagus: The muscular tube that connects the pharynx to the stomach, carrying food and liquid.
Thymus Gland: An organ of the immune system that is especially active during childhood.
Major Blood Vessels: The aorta, superior vena cava, and inferior vena cava all pass through or originate within the thorax, managing the body's major blood flow.

Muscles and Soft Tissues of the Upper Torso

Beyond the bones and organs, the thorax is supported by a complex network of muscles and soft tissues that enable movement and function.

Diaphragm: This dome-shaped muscle separates the thoracic cavity from the abdominal cavity and is the primary muscle of respiration.
Intercostal Muscles: Located between the ribs, these muscles play a crucial role in breathing by assisting in the expansion and contraction of the thoracic cage.
Pectoral Muscles: The major and minor pectoral muscles are located at the front of the chest, connecting the upper body to the arms.
Trapezius and Latissimus Dorsi: Large muscles of the back that contribute to movement and posture in the upper torso.

Comparison: Thorax vs. Abdomen

To further clarify what is the upper half of the torso called, comparing it to the lower half—the abdomen—is useful. While both are part of the larger trunk, their structure and function differ significantly.


Feature	Thorax (Upper Torso)	Abdomen (Lower Torso)
Boundaries	Extends from the base of the neck to the diaphragm.	Extends from the diaphragm to the pelvis.
Primary Organs	Heart, lungs, trachea, and esophagus.	Stomach, liver, intestines, pancreas, and kidneys.
Protection	Encased in the rigid, bony thoracic cage (ribs and sternum) for maximum protection.	Primarily protected by abdominal muscles; lacks the extensive bony protection of the thorax.
Musculature	Includes the diaphragm, intercostal muscles, and pectoral muscles.	Features rectus abdominis, obliques, and transverse abdominal muscles.
Key Function	Respiration and circulation.	Digestion, waste filtration, and other metabolic processes.

The Importance of Thoracic Health

Given the critical organs located within it, the health of the thorax is paramount. Conditions affecting the lungs, such as pneumonia or chronic obstructive pulmonary disease (COPD), or the heart, like myocardial infarction, all involve this region. Maintaining good respiratory and cardiovascular health through regular exercise, a balanced diet, and avoiding harmful habits like smoking is essential. The muscular health of the thorax and back is also vital for posture, movement, and preventing musculoskeletal issues. Regular strength training and stretching can help support the thoracic cage and spine, reducing the risk of injury.

Conclusion

The upper half of the torso is called the thorax, a region of immense anatomical and physiological importance. Its unique bony structure protects the heart and lungs, while its complex network of muscles enables crucial functions like breathing. A comprehensive understanding of the thorax highlights the interconnected nature of our body's systems and reinforces the importance of maintaining its health. For further reading, an excellent resource on general anatomy and physiology can be found at the National Cancer Institute's SEER training modules, which provide detailed information on various body regions and functions.

Frequently Asked Questions

While the chest is the most common term used colloquially, the anatomical term for the upper half of the torso is the thorax. The chest is technically the front part of the thorax, between the neck and the diaphragm.

The diaphragm is a crucial, dome-shaped muscle that separates the upper half of the torso (thorax) from the lower half (abdomen). Its primary role is to assist with breathing by contracting and relaxing.

The upper half of the torso, or thorax, houses several vital organs, including the heart, lungs, and thymus gland. It also contains the trachea, esophagus, and major blood vessels like the aorta.

The thorax is protected by a bony structure called the thoracic cage, which consists of the ribs, the sternum (breastbone), and the thoracic vertebrae. This framework shields the delicate organs within.

In anatomy, the terms torso and trunk are often used interchangeably to refer to the central part of the body, excluding the head, neck, and limbs. The trunk is typically considered the same as the torso, and the thorax is the upper part of this larger region.

Yes, because the thorax houses the heart and lungs, any issues in this region can have a systemic impact. For example, a cardiac problem can cause referred pain in the arms, and respiratory issues can affect oxygen levels throughout the body.

The thorax is subject to various clinical conditions, including chest pain, respiratory infections, trauma like rib fractures, and more serious issues affecting the heart or lungs, such as heart attacks or pneumothorax.