The chest is a part of the anatomy

Anatomy

Anatomy is a branch of biology and medicine that is the consideration of the structure of living things. It is a general term that includes human anatomy, animal anatomy , and plant anatomy...

 of humans and various other animals. It is sometimes referred to as the thorax

Thorax

The thorax is a division of an animal's body that lies between the head and the abdomen.-In tetrapods:...

 or the bosom.
In hominid

Hominidae

The Hominidae or include them .), as the term is used here, form a taxonomic family, including four extant genera: chimpanzees , gorillas , humans , and orangutans ....

s, the chest is the region of the body between the neck

Neck

The neck is the part of the body, on many terrestrial or secondarily aquatic vertebrates, that distinguishes the head from the torso or trunk. The adjective signifying "of the neck" is cervical .-Boner anatomy: The cervical spine:The cervical portion of the human spine comprises seven boney...

 and the abdomen

Abdomen

In vertebrates such as mammals the abdomen constitutes the part of the body between the thorax and pelvis. The region enclosed by the abdomen is termed the abdominal cavity...

, along with its internal organs

Organ (anatomy)

In biology, an organ is a collection of tissues joined in structural unit to serve a common function. Usually there is a main tissue and sporadic tissues . The main tissue is the one that is unique for the specific organ. For example, main tissue in the heart is the myocardium, while sporadic are...

 and other contents. It is mostly protected and supported by the ribcage, spine

Vertebral column

In human anatomy, the vertebral column is a column usually consisting of 24 articulating vertebrae, and 9 fused vertebrae in the sacrum and the coccyx. It is situated in the dorsal aspect of the torso, separated by intervertebral discs...

, and shoulder

Shoulder

The human shoulder is made up of three bones: the clavicle , the scapula , and the humerus as well as associated muscles, ligaments and tendons. The articulations between the bones of the shoulder make up the shoulder joints. The major joint of the shoulder is the glenohumeral joint, which...

 girdle. Contents of the chest include the following:

• organs
  • heart
    Heart
    The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...
    
    
  • lungs
  • Thymus
    Thymus
    The thymus is a specialized organ of the immune system. The thymus produces and "educates" T-lymphocytes , which are critical cells of the adaptive immune system....
    
    

• muscles
  • major
    Pectoralis major muscle
    The pectoralis major is a thick, fan-shaped muscle, situated at the chest of the body. It makes up the bulk of the chest muscles in the male and lies under the breast in the female...
    
     and minor
    Pectoralis minor muscle
    The pectoralis minor is a thin, triangular muscle, situated at the upper part of the chest, beneath the pectoralis major.-Origin and insertion:...
    
     pectoral muscles
  • trapezius muscle
    Trapezius muscle
    In human anatomy, the trapezius is a large superficial muscle that extends longitudinally from the occipital bone to the lower thoracic vertebrae and laterally to the spine of the scapula...
    
    s and neck
    Neck
    The neck is the part of the body, on many terrestrial or secondarily aquatic vertebrates, that distinguishes the head from the torso or trunk. The adjective signifying "of the neck" is cervical .-Boner anatomy: The cervical spine:The cervical portion of the human spine comprises seven boney...
    
    
• internal structures
  • diaphragm
  • esophagus
    Esophagus
    The esophagus is an organ in vertebrates which consists of a muscular tube through which food passes from the pharynx to the stomach. During swallowing, food passes from the mouth through the pharynx into the esophagus and travels via peristalsis to the stomach...
    
    
  • trachea
    Vertebrate trachea
    In tetrapod anatomy the trachea, or windpipe, is a tube that connects the pharynx or larynx to the lungs, allowing the passage of air. It is lined with pseudostratified ciliated columnar epithelium cells with goblet cells that produce mucus...
    
    
  • xiphoid process
    Xiphoid process
    The xiphoid process, or xiphisternum or metasternum, is a small cartilaginous process of the lower part of the sternum which is usually ossified in the adult human. By age 15 to 29, the xiphoid usually fuses to the body of the sternum with a fibrous joint. Unlike the synovial articulation of major...
    
    
• arteries and veins
  • aorta
    Aorta
    The aorta is the largest artery in the body, originating from the left ventricle of the heart and extending down to the abdomen, where it branches off into two smaller arteries...
    
    
  • superior vena cava
    Superior vena cava
    The superior vena cava is truly superior, a large diameter, yet short, vein that carries deoxygenated blood from the upper half of the body to the heart's right atrium...
    
    
  • inferior vena cava
    Inferior vena cava
    The inferior vena cava , also known as the posterior vena cava, is the large vein that carries de-oxygenated blood from the lower half of the body into the right atrium of the heart....
    
    
  • pulmonary artery
    Pulmonary artery
    The pulmonary arteries carry deoxygenated blood from the heart to the lungs. They are the only arteries that carry deoxygenated blood....
    
    
• bones
  • the shoulder socket containing the upper part of the humerus
    Humerus
    The humerus is a long bone in the arm or forelimb that runs from the shoulder to the elbow....
    
    
  • scapula
    Scapula
    In anatomy, the scapula , omo, or shoulder blade, is the bone that connects the humerus with the clavicle ....
    
    
  • sternum
  • thoracic portion of the spine
    Thoracic vertebrae
    In human anatomy, twelve thoracic vertebrae compose the middle segment of the vertebral column, between the cervical vertebrae and the lumbar vertebrae. They are intermediate in size between those of the cervical and lumbar regions; they increase in size as one proceeds down the spine, the upper...
    
    
  • collarbone
  • ribcage
  • Floating rib
    Floating rib
    Floating ribs are four atypical ribs in the human ribcage. They are called so because they are attached to the vertebrae only, and not to the sternum or cartilage coming off of the sternum. Some people are missing one of the two pairs. Others have a third pair. Most, however, possess only two...
    
    s
• external structures
  • nipple
    Nipple
    In its most general form, a nipple is a structure from which a fluid emanates. More specifically, it is the projection on the breasts or udder of a mammal by which breast milk is delivered to a mother's young. In this sense, it is often called a teat, especially when referring to non-humans, and...
    
    s
  • mammary gland
    Mammary gland
    A mammary gland is an organ in mammals that produces milk to feed young offspring. Mammals get their name from the word "mammary". In ruminants such as cows, goats, and deer, the mammary glands are contained in their udders...
    
    s
  • The V of the chest is the area exposed by open-necked shirts.
• thoracic abdomen (stomach
  Stomach
  The stomach is a muscular, hollow, dilated part of the alimentary canal which functions as an important organ of the digestive tract in some animals, including vertebrates, echinoderms, insects , and molluscs. It is involved in the second phase of digestion, following mastication .The stomach is...
  
  , kidney
  Kidney
  The kidneys, organs with several functions, serve essential regulatory roles in most animals, including vertebrates and some invertebrates. They are essential in the urinary system and also serve homeostatic functions such as the regulation of electrolytes, maintenance of acid–base balance, and...
  
  /adrenal, pancreas
  Pancreas
  The pancreas is a gland organ in the digestive and endocrine system of vertebrates. It is both an endocrine gland producing several important hormones, including insulin, glucagon, and somatostatin, as well as a digestive organ, secreting pancreatic juice containing digestive enzymes that assist...
  
  , spleen
  Spleen
  The spleen is an organ found in virtually all vertebrate animals with important roles in regard to red blood cells and the immune system. In humans, it is located in the left upper quadrant of the abdomen. It removes old red blood cells and holds a reserve of blood in case of hemorrhagic shock...
  
  , and lower oesophagus)

In humans, the portion of the chest protected by the ribcage is also called the thorax

Thorax

The thorax is a division of an animal's body that lies between the head and the abdomen.-In tetrapods:...

.
Injury to the chest (also referred to as chest trauma, thoracic injury, or thoracic trauma) results in up to ¼ of all deaths due to trauma

Physical trauma

Trauma refers to "a body wound or shock produced by sudden physical injury, as from violence or accident." It can also be described as "a physical wound or injury, such as a fracture or blow." Major trauma can result in secondary complications such as circulatory shock, respiratory failure and death...

 in the United States.
Different types of diseases or conditions that can be experienced in the chest include pleurisy

Pleurisy

Pleurisy is an inflammation of the pleura, the lining of the pleural cavity surrounding the lungs. Among other things, infections are the most common cause of pleurisy....

, flail chest

Flail chest

A flail chest is a life-threatening medical condition that occurs when a segment of the rib cage breaks under extreme stress and becomes detached from the rest of the chest wall. It occurs when multiple adjacent ribs are broken in multiple places, separating a segment, so a part of the chest wall...

, atelectasis

Atelectasis

Atelectasis is defined as the collapse or closure of alveoli resulting in reduced or absent gas exchange. It may affect part or all of one lung. It is a condition where the alveoli are deflated, as distinct from pulmonary consolidation.It is a very common finding in chest x-rays and other...

, and the most common condition, chest pain.