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Study of Human Thorax with Functions

The biology of advanced organisms is quite mesmerizing. The modifications of different organs over the years due to evolution and adaptation are fascinating. One of the important parts of mammals and tetrapods is the development of the thorax. It is a cage-like cavity protected by an exoskeleton or bones. It contains the vital organs that are required for basic body functions. In this segment, we will learn thorax anatomy and its functions in human physiology. We will concentrate on the development and physiology of the human thorax and its functions.

What is Thorax?

Thorax, as per its definition, is the significant part of the body between the head and abdomen. This definition fits all the animals whose bodies are differentiated into head, thorax, and abdomen. The human thorax is more complicated than the rest of the animals. The development of this part of the body signifies the difference between tetrapods, aquatic animals, and bipedal animals. It is common among fishes, amphibians, avians, mammals, and reptiles. It can also be considered as the chest part of these animals.

The vertebrates have a stronger thorax than the invertebrates as it is protected by an internal musculoskeletal system. It protects the vital organs present inside the thoracic cavity such as the lungs, a part of the respiratory system, and the heart. It can be concluded the prime function of the thorax is to support and protect the respiratory and circulatory systems of the animals.

What is the Human Thorax?

Now that you have understood the thorax meaning, here is a detailed description of the human thorax and its anatomy. It is an important part of the human anatomy that supports the middle part of the body. The different parts of the anatomy of the thorax are:

  • Thoracic wall 

The inner lining of the thoracic cavity is called the thoracic wall. It is made of muscles, epithelial tissues, a skeletal cage made of bones, muscles, and joints. The space between the 12 pairs of ribs is called intercostal space. This space is made of muscles, blood vessels, and apertures.

  •  Thoracic Cavity

The cavity is the empty portion in this part of the human body that contains a pair of lungs, the heart, and the important blood vessels originating from it. It is guarded by the diaphragm, a platform of strong muscles, below the lungs that help in breathing.

  •  Neurovasculature of Thorax Anatomy

The neural and circulatory vessels in this space comprise the neurovasculature. The three main arteries (left common carotid artery, brachiocephalic trunk, and left subclavian artery) appear from the thoracic aorta. In fact, the major veins in the thoracic are the azygos venous system, superior vena cava, pulmonary veins, accessory hemiazygos vein, esophageal veins, internal thoracic veins, superior intercostal veins, and cardiac veins.

  •  Organs

The organs present in the human chest anatomy are the trachea, oesophagus, thymus, lungs, and heart.

There is no such thing as the prothorax in human body. It is the upper segment of the thoracic cavity of the insects that contain the respiratory organs and the first pair of legs. The mesothorax, on the other hand, is bigger than the prothorax of the insects and contains a pair of legs, the forewings (if present), and spiracles.

Functions of the Human Thorax

As we have learned the thorax meaning, the functions of this body part should be elaborately studied too. This part of the human body lies in the middle portion and is attached to the vertebral column at the back. It is also called the chest. Let us find out what its functions are:

  • Support

If you look at the organs present in the thoracic cavity carefully, you will find they are not capable of staying inflated due to the lack of a strong foundation or support. This is where the support from the thoracic cage comes in handy. The rib cage and the muscles provide an intricate support system, as well as, a platform for the organs. For instance, the pair of lungs remains in a resting position without getting deflated or constricted. Hence, this portion helps us to breathe.

It also supports the most vital organ of the circulatory system, the heart. It also supports three major arteries and the major veins opening and continuing to the rest of the body parts. It also supports proper blood circulation in our entire body. The prothorax in the human body also supports the functioning of the arms.

  • Protection

Another thorax function is to provide ample protection to the internal organs from shock and injuries. The rib cage can handle huge pressure, impacts, and shock to a considerable extent. It thus helps in keeping our breathing and circulatory system safe. The bones are flexible to some extent offering a brilliant skeletal system for breathing too. It also acts as a platform for connection between muscles, bones, tendons, and cartilages.


The thorax in the human body is an essential portion of the anatomy as it supports and protects major organs that are important for our survival.

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FAQs on Thorax

1. Which Part of the Human Body is called the Thorax?

Ans: Thorax is the part between the head and the abdomen of human anatomy. It comprises the lungs, heart, major arteries, and veins of the circulatory system, trachea, and oesophagus.

2.  What is the difference between the Thorax of Humans and Insects?

Ans: The insects have thorax in between their head and abdomen. They do not have an internal skeletal system rather an exoskeleton that protects the thorax region. They also have pairs of legs attached to their thorax. Humans, on the other hand, have internal skeletal support for the thorax. It is partially attached to a pair of arms.

3.  How can you Study what is Thorax Properly?

Ans: The easiest way to study the anatomy of the human thorax is to draw an image and point out each part of it. It will help you to understand which part lies where and what its functions are. Study thorax by keeping a detailed diagram handy.