Thorax

The thorax, also called the chest, is an important part of the body for many animals, including humans. In people and other mammals, the thorax lies between the neck and the abdomen. It is a special area that holds some very important organs.

Inside the human thorax is a space called the thoracic cavity, which is protected by the thoracic wall. This cavity contains the heart, the lungs, and the thymus gland. These organs work together to help us breathe and keep our blood flowing.

The thorax is also found in other animals. For example, in insects, crustaceans, and ancient trilobites, the body is divided into three main parts, and the thorax is one of them. Each part of these animals is made up of several segments.

Sometimes, problems can happen in the chest area, and one of the most common signs is chest pain. Understanding the thorax helps doctors know how to take care of these issues.

Etymology

The word "thorax" comes from an old Greek word meaning "breastplate." It traveled from Greek to Latin before we started using it today.

Humans

Structure

In humans and other great apes, the thorax is the chest area between the neck and the abdomen. It holds important organs and structures and is protected by the rib cage, spine, and shoulder area.

Contents

The thorax contains the heart and lungs, along with muscles, the windpipe, food pipe, and other important parts. Bones like the ribs, spine, and shoulder blades also help protect these organs.

Chest

The front part of the thorax between the neck and the muscle under the chest is called the chest. This area is shaped by the bones and muscles that support and protect the organs inside.

Bones

The bones of the thorax, called the thoracic skeleton, include the ribs and breastbone. These bones help protect the heart, lungs, and major blood vessels.

Landmarks

Doctors use special points on the chest to describe its shape and position, such as the location of the nipples and the shape of the breast in females.

Clinical significance

Different diseases or conditions can affect the chest. These include problems that make breathing difficult or cause pain. Some of these conditions are inherited, while others are caused by injuries or problems present at birth.

Injury

Injuries to the chest can be serious and are a common cause of death from accidents. These injuries can make breathing difficult and affect the flow of air and blood in the body.

Pain

Chest pain can come from many different causes, including problems with breathing, digestion, or muscles. It can sometimes be a sign of a heart problem, so it's important to take chest pain seriously. Symptoms of heart problems can include a feeling of pressure in the chest, sweating, shortness of breath, dizziness, and irregular heartbeats.

Non-cardiac causes

Not all chest pain is from the heart. It can also come from increased activity, infections, or injuries to the ribs or breastbone. Pain might feel worse when taking deep breaths or coughing.

Atelectasis

Atelectasis is when part of the lung collapses because it's not getting enough air. This can happen if something blocks the airways, like mucus, a tumor, or a foreign object.

Pneumothorax

Pneumothorax is when air builds up in the space around the lung. This can happen without a clear reason or because of a lung disease or injury. If not treated, it can affect blood flow and cause serious problems. Smaller cases might get better on their own.

Images

• Volume rendering of a high resolution computed tomography of the thorax. The anterior thoracic wall, the airways and the pulmonary vessels anterior to the root of the lung have been digitally removed in order to visualize the different levels of the pulmonary circulation.

• Thorax. Anterior view.

• Thorax. Anterior view.

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  Clearly visible thorax of an artistic gymnast.

Tetrapods

In mammals, the thorax is the upper body area made up of the breastbone, special back bones, and ribs. It stretches from the neck down to a muscle called the diaphragm, but it does not include the arms. Important parts like the heart and lungs are inside this area, protected by the rib cage and the breastbone. Birds also have these special back bones, but reptiles do not.

Arthropods

The body of trilobites was split into three main parts: a head with eyes and antennae, a middle section called the thorax made of many similar pieces, and a tail section.

In insects, crustaceans, and trilobites, the thorax is the middle of the three main body parts. It is made of many smaller pieces. In insects, wings and legs are attached to the thorax. The thorax of most insects has three parts, but in some types of insects, it has four. Each piece of the thorax is divided into different sections, including a back part, side parts, and a bottom part. These sections may be made of several plates connected by flexible material.