Thorax: Definition, Function, Diagram and Examples
The thorax, or chest cavity, houses vital organs like the heart and lungs and plays a central role in breathing and circulation. Protected by the rib cage, sternum, and thoracic vertebrae, it ensures stability and safe functioning of major systems. Understanding thoracic anatomy, mechanisms, and clinical conditions is essential for NEET, nursing, and medical entrance exams.
This Story also Contains
- What Is The Thorax?
- Anatomy Of The Thorax
- Functions Of The Thorax
- Clinical Aspects Of The Thorax
- Thorax NEET MCQs (With Answers & Explanations)
- Recommended Video on "Thorax"
What Is The Thorax?
The thorax is a body part commonly known as the chest area and is located between the cervical and the abdominal cavities. It accommodates the heart and lungs though they are shielded by the rib cage of the human body. In humans and many other organisms, the thorax is of great significance because it introduces a cavity that facilitates movements of respiratory organs in respiration as well as movements of circulatory organs in circulation. To summarize, it is crucial for the stability, as well as the functionality, of the respiratory and cardiovascular systems. Thus, it occupies a rather crucial place in both human and animal physiology.
Anatomy Of The Thorax
The structure of the thorax has the following components:
Thoracic Skeleton
The thoracic cavity is formed by the thoracic part of the vertebral column, sternum, and ribs which encase the heart and lungs. The sternum is smooth at the bottom and linked to the ribs through cartilage; the ribs are connected to the thoracic vertebrae at the back.
Thoracic Muscles
Some of them are intercostal muscles that help in respiration as well as contraction of the chest, and the diaphragm which has a significant role in increasing the volume of the thoracic cavity. The muscles are the scalene and the sternocleidomastoid which assist in deep breathing.
Thoracic Cavity
The thoracic cavity is part of the body is enclosed by the rib cage, sternum and thoracic vertebra; subdivided into two pleural cavities containing the lungs and the mediastinum which contain the heart, oesophagus and trachea.
Functions Of The Thorax
The functions of the thorax are:
Protection Of Vital Organs
The thorax safeguards structures like the heart, lungs and the majority of blood vessels against physical harm. The rib bones and sternum create a strong armour that effectively protects the injured, the thoracic vertebra also supports the spinal column as well as the nerve trunks.
Respiration
For breathing, one has to use the thorax to expand while taking in air and contracting while expelling the air. The diaphragm which becomes flattened on contraction lifts the lower ribs and strokes the thoracic cavity larger thus creating a vacuum that pulls the air into the lungs. Since breathing entails the movement of air in and out, the intercostal muscles also help in lifting and lowering of ribs.
Circulation
The thorax was also concerned with the circulation of blood since it contains the heart and large vessels including the aorta and pulmonary arteries. Thoracic movement during respiration also facilitates the return of the blood in the veins to the heart and promotes proper blood circulation in the thoracic cavity.
Clinical Aspects Of The Thorax
The thorax can have these issues:
Thoracic Injuries
Thoracic injuries, which include the ribs or any blunt force, pose a risk to the organs within the thoracic cavity which include the lungs and heart. Broken ribs can be painful and hinder the patient’s ability to breathe while severe injuries may cause internal bleeding or affect their breathing.
Chest Pain Causes
Most people experience chest pain in the thoracic region from numerous causes like costochondritis, which is a non-serious condition, but also from serious conditions like myocardial infarction or pulmonary embolism. They can be described as sharp, dull or pressurising pain and usually cannot be distinguished until further investigations are done to establish the cause.
Atelectasis
Atelectasis means the lung or certain lobe does not inflate as it should, possibly resulting from obstruction or pressure injury. It can occur due to pneumonia, tumour or after operation and it causes less oxygenation and breathing problems.
Pneumothorax
Pneumothorax on the other hand is caused by the entrapment of air in the pleural cavity hence making the lung collapse. It may be caused by trauma, medical treatment, or development on its own. Thus causing sharp chest pain and breathing with difficulty. Management might entail the aspiration of the air and allow the lung to reinflate.
Thorax NEET MCQs (With Answers & Explanations)
Important topics for NEET are:
Functions and anatomy of thorax
Clinical aspects of Thorax
Practice Questions for NEET
Q1. Which of the following statements about the pleural cavity is incorrect?
It is a potential space between the visceral and parietal pleura.
It is filled with pleural fluid.
It helps reduce friction during breathing.
It is located within the mediastinum.
Correct answer: 4) It is located within the mediastinum
Explanation:
The mediastinum does not contain the pleural cavity. The heart, major vessels, esophagus, and trachea are all located in the mediastinum, which is the thoracic cavity's core compartment. On the other hand, the visceral and parietal pleura, two layers of serous membrane that encircle the lungs, may be separated by the pleural cavity. Pleural fluid, which fills the pleural cavity, serves to lessen friction while breathing and enables the lungs to expand and contract without resistance.
Hence, the correct answer is option 4) It is located within the mediastinum.
Q2. Oblique fissure is present in
Left lung
Right lung
Both
None
Correct answer: 3) Both
Explanation:
The right lung consists of three lobes—superior, middle, and inferior—separated by two fissures: the horizontal fissure (between the superior and middle lobes) and the oblique fissure (between the middle and inferior lobes). In contrast, the left lung has only two lobes—superior and inferior—divided by a single oblique fissure. The left lung is slightly smaller than the right lung due to the space occupied by the heart, and it lacks the middle lobe that is present in the right lung.
Hence, the correct answer is option 3) Both.
Q3. Where are lungs situated in the human body ?
Abdominal cavity
Thoracic cavity
Coelomic cavity
Pleural cavity
Correct answer: 2) Thoracic cavity
Explanation:
The lungs are situated in an air-tight chamber called the thoracic chamber. The thoracic chamber is formed dorsally by the vertebral column, ventrally by the sternum, laterally by the ribs, and on the lower side by the dome-shaped diaphragm.
Hence, the correct answer is option 2) Thoracic cavity.
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Recommended Video on "Thorax"
Frequently Asked Questions (FAQs)
The mammal will have a rib cage as well as a diaphragm comparable to humans. However, birds and reptiles have different ribs and respiratory muscles for their breathing styles.
Other ordinary illnesses and factors are rib break, pneumonia, atelectasis, pneumothorax as well as thoracic pain resulting from costochondritis or myocardial infarction.
The thorax is the organ of the heart, lungs, gullet, trachea and major blood vessels such as the aorta and pulmonary arteries.
The rib cage and the sternum that begins at the base of the neck cup the highly vulnerable heart and lungs and shield them from different physical impacts.
The limbs that make up the thorax include; it is mainly comprised of four limbs that are vital for protecting vital body organs, and circulation since they hold the heart and major vessels while the lungs for respiration.