The thorax is a vital part of the human body, serving as a protective bony cage for the vital organs and tissues that make up the chest cavity. It is cone-shaped and about as wide as it is deep.
12 pairs of ribs on each side make up the thorax, which articulates with the thoracic vertebrae in the back.
In this article, we’ll talk more about the thorax’s structure and what it does.
Key takeaways
- The thorax is made up of 12 pairs of ribs on each side, and it articulates with the thoracic vertebrae in the back.
- The sternum is an elongated flat bone that forms the middle portion of the upper half of the chest wall in front, and it is made up of three parts: the manubrium, the body, and the xiphoid process.
- The thorax serves as a protective cage for the vital organs and tissues that make up the chest cavity, including the heart, lungs, and major blood vessels. It also provides a stable base for the attachment of the upper extremities and helps to maintain the shape and structure of the chest wall.
- The thorax is an important part of the respiratory system, as it houses the lungs and provides a framework for their expansion and contraction during breathing.
- The thorax also houses the heart and major blood vessels of the body, and injuries and disorders of the thorax can have serious consequences for the body.
The ribs
The ribs are the main structure that makes up the thorax. The first set of ribs is attached to the manubrium, a flat, irregular bone atop the sternum.
The first seven pairs of ribs are called “true ribs,” as their cartilages reach the sternum directly.
The remaining five pairs of ribs are called false ribs, as their cartilages do not reach the sternum directly.
The cartilages connecting the eighth, ninth, and tenth ribs to the rib above are what connect them.
The last two rib pairs, also known as “floating ribs,” have no cartilaginous attachments to the sternum.
The sternum
The sternum is an elongated flat bone that forms the middle portion of the upper half of the chest wall in front.
It is made up of three parts: the manubrium, the body, and the xiphoid process. The manubrium is the top portion of the sternum that articulates with the clavicles and the first pair of ribs.
The body is the largest part of the sternum and articulates with the second through seventh pairs of ribs. The xiphoid process is at the bottom of the sternum.
It is where the diaphragm and rectus abdominis muscles connect to the sternum.
The function of the thorax
The thorax serves as a protective cage for the vital organs and tissues that make up the chest cavity, including the heart, lungs, and major blood vessels.
It also provides a stable base for the attachment of the upper extremities and helps to maintain the shape and structure of the chest wall.
The respiratory system
The thorax is an important part of the respiratory system, as it houses the lungs and provides a framework for their expansion and contraction during breathing.
The diaphragm, a thin, dome-shaped muscle that separates the chest cavity from the abdominal cavity, plays a crucial role in breathing.
When it contracts, it flattens out and moves downward, creating more space in the chest cavity and allowing the lungs to expand.
When it relaxes, it moves back up into its dome shape, pushing air out of the lungs.
The cardiovascular system
The thorax also houses the heart and the major blood vessels of the body.
The heart is a muscular organ that pumps blood throughout the body, and it is located in the center of the chest, just behind the sternum.
The major blood vessels that enter and exit the heart are the superior and inferior vena cava, the pulmonary arteries and veins, and the aorta.
Injuries and disorders of the thorax
Injuries and disorders of the thorax can have serious consequences for the body.
Common injuries include fractures or dislocations of the ribs or sternum, as well as injuries to the lungs, heart, or major blood vessels.
Some things that can go wrong with the thorax are pneumonia, pleurisy, asthma, and chronic obstructive pulmonary disease (COPD).
The thorax plays a crucial role in protecting the vital organs and tissues that make up the chest cavity, including the heart, lungs, and major blood vessels.
The 12 pairs of ribs on each side and the sternum provide a stable base for the attachment of the upper extremities and help to maintain the shape and structure of the chest wall.
The thorax is also an important part of the respiratory and cardiovascular systems, as it houses the lungs and heart, respectively.
