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.
Conclusion
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.
FAQs on Thorax
1. What is the human thorax and where is it located in the body?
The thorax, commonly known as the chest, is the region of the body located between the neck and the abdomen. It is enclosed by the rib cage and contains the principal organs of the respiratory and circulatory systems. The floor of the thoracic cavity is formed by the diaphragm, a major muscle involved in breathing.
2. What are the main anatomical structures that form the thoracic cage?
The thoracic cage, or rib cage, provides a protective framework for the vital organs. It is composed of three main types of bones:
- Sternum: The flat bone located in the anterior midline of the chest.
- Ribs: There are 12 pairs of ribs. The first seven pairs are 'true ribs' (connected directly to the sternum), the next three are 'false ribs' (connected indirectly via cartilage), and the last two are 'floating ribs' (not connected to the sternum).
- Thoracic Vertebrae: The 12 vertebrae of the spine to which the ribs articulate posteriorly.
3. What are the primary functions of the thorax?
The thorax serves two critical functions in the human body:
- Protection: The strong but flexible thoracic cage shields vital organs such as the heart, lungs, and major blood vessels (like the aorta and vena cava) from external injury.
- Respiration: The structure of the thoracic cage, along with the diaphragm and intercostal muscles, allows it to expand and contract. This movement changes the volume and pressure inside the thoracic cavity, facilitating the process of breathing (inhalation and exhalation).
4. Which vital organs are housed within the thoracic cavity?
The thoracic cavity contains several essential organs, including the heart, which is enclosed in the pericardial cavity, and the two lungs, located on either side. It also houses the lower parts of the respiratory tract like the trachea and bronchi, the oesophagus, the thymus gland, and major blood vessels and nerves.
5. How does the structure of the thoracic cage facilitate the mechanism of breathing?
The unique structure of the thoracic cage is fundamental to breathing. During inhalation, the diaphragm contracts and flattens, while the external intercostal muscles lift the ribs up and outwards. This increases the volume of the thoracic cavity, creating negative pressure that draws air into the lungs. During exhalation, these muscles relax, decreasing the thoracic volume and forcing air out. This mechanical process is a perfect example of how anatomy supports physiological function.
6. What are the key differences between the thorax in humans and in insects?
The thorax in humans and insects differs significantly in structure and function. In humans, the thorax has an internal bony skeleton (endoskeleton) primarily for protecting organs and aiding respiration. In insects, the thorax is a distinct body segment with a tough outer covering (exoskeleton) and is mainly responsible for locomotion, as it is the point of attachment for their legs and wings.
7. Why is a clear understanding of the thorax's anatomy important in medicine?
Understanding the thorax is crucial for medical diagnosis and treatment. Knowledge of the exact location of organs is essential for procedures like chest X-rays, CT scans, and electrocardiograms (ECG) to detect heart and lung diseases. Furthermore, surgeons rely on thoracic landmarks for operations, and first responders use them for life-saving techniques like Cardiopulmonary Resuscitation (CPR), which involves chest compressions over the sternum.
8. Are there any significant anatomical differences in the thorax of human males and females?
While the fundamental structure of the thorax is the same in both sexes, there are some average anatomical differences. The female thorax is generally smaller in capacity, the sternum is often shorter, and the upper part of the rib cage can be narrower. These are general variations related to overall body size and shape, and the primary components and functions remain identical.
