Carina of trachea

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Carina of trachea
Cartilages of larynx, trachea and bronchi. (Carina is at the point of bifurcation.)
Transverse section of the trachea, just above its bifurcation, with a bird’s-eye view of the interior. (Carina not labeled; the ridge that separates the left and right bronchus.)
System Respiratory system
Latin Carina tracheae, bifurcatio tracheae
TA A06.3.01.009
FMA 7465
Anatomical terminology

In anatomy, the carina is a ridge of cartilage in the trachea that occurs between the division of the two main bronchi. This occurs at the lower end of the trachea (usually at the level of the 4th thoracic vertebra, which is in line with the sternal angle, but may raise or descend up to two vertebrae higher or lower with breathing). This ridge lies to the left of the midline, and runs antero-posteriorly (front to back). Foreign bodies that fall down the trachea are more likely to enter the right bronchus.

Cartilage resilient and smooth elastic tissue, rubber-like padding that covers and protects the ends of long bones at the joints

Cartilage is a resilient and smooth elastic tissue, a rubber-like padding that covers and protects the ends of long bones at the joints, and is a structural component of the rib cage, the ear, the nose, the bronchial tubes, the intervertebral discs, and many other body components. It is not as hard and rigid as bone, but it is much stiffer and much less flexible than muscle. The matrix of cartilage is made up of glycosaminoglycans, proteoglycans,collagen fibers and, sometimes, elastin.

Bronchus airway in the respiratory tracti

A bronchus is a passage of airway in the respiratory system that conducts air into the lungs. The first bronchi to branch from the trachea are the right main bronchus and the left main bronchus. These are the widest and enter the lungs at each hilum, where they branch into narrower secondary bronchi known as lobar bronchi, and these branch into narrower tertiary bronchi known as segmental bronchi. Further divisions of the segmental bronchi are known as 4th order, 5th order, and 6th order segmental bronchi, or grouped together as subsegmental bronchi. The bronchi when too narrow to be supported by cartilage are known as bronchioles. No gas exchange takes place in the bronchi.

Thoracic vertebrae vertebrae between the cervical vertebrae and the lumbar vertebrae

In vertebrates, thoracic vertebrae compose the middle segment of the vertebral column, between the cervical vertebrae and the lumbar vertebrae. In humans, there are twelve thoracic vertebrae and they are intermediate in size between the cervical and lumbar vertebrae; they increase in size going towards the lumbar vertebrae, with the lower ones being a lot larger than the upper. They are distinguished by the presence of facets on the sides of the bodies for articulation with the heads of the ribs, as well as facets on the transverse processes of all, except the eleventh and twelfth, for articulation with the tubercles of the ribs. By convention, the human thoracic vertebrae are numbered T1–T12, with the first one (T1) located closest to the skull and the others going down the spine toward the lumbar region.

The mucous membrane of the carina is the most sensitive area of the trachea and larynx for triggering a cough reflex. Widening and distortion of the carina is a serious sign because it usually indicates carcinoma of the lymph nodes around the region where the trachea divides.

Carcinoma A category of types of cancer that develops from epithelial cells

Carcinoma is a category of types of cancer that develop from epithelial cells. Specifically, a carcinoma is a cancer that begins in a tissue that lines the inner or outer surfaces of the body, and that arises from cells originating in the endodermal, mesodermal or ectodermal germ layer during embryogenesis.

Lymph node organ of the lymphatic system

A lymph node or lymph gland is an ovoid or kidney-shaped organ of the lymphatic system, and of the adaptive immune system, that is widely present throughout the body. They are linked by the lymphatic vessels as a part of the circulatory system. Lymph nodes are major sites of B and T lymphocytes, and other white blood cells. Lymph nodes are important for the proper functioning of the immune system, acting as filters for foreign particles and cancer cells. Lymph nodes do not have a detoxification function, which is primarily dealt with by the liver and kidneys.

Tracheobronchial injury, an injury to the airways, occurs within 2.5 cm of the carina 60% of the time. [1]

Tracheobronchial injury damage to the tracheobronchial tree

Tracheobronchial injury (TBI) is damage to the tracheobronchial tree. It can result from blunt or penetrating trauma to the neck or chest, inhalation of harmful fumes or smoke, or aspiration of liquids or objects.

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Lung essential respiration organ in many air-breathing animals

The lungs are the primary organs of the respiratory system in humans and many other animals including a few fish and some snails. In mammals and most other vertebrates, two lungs are located near the backbone on either side of the heart. Their function in the respiratory system is to extract oxygen from the atmosphere and transfer it into the bloodstream, and to release carbon dioxide from the bloodstream into the atmosphere, in a process of gas exchange. Respiration is driven by different muscular systems in different species. Mammals, reptiles and birds use their different muscles to support and foster breathing. In early tetrapods, air was driven into the lungs by the pharyngeal muscles via buccal pumping, a mechanism still seen in amphibians. In humans, the main muscle of respiration that drives breathing is the diaphragm. The lungs also provide airflow that makes vocal sounds including human speech possible.

Trachea cartilaginous tube that connects the pharynx and larynx to the lungs

The trachea, colloquially called the windpipe, is a cartilaginous tube that connects the pharynx and larynx to the lungs, allowing the passage of air, and so is present in almost all air-breathing animals with lungs. The trachea extends from the larynx and branches into the two primary bronchi. At the top of the trachea the cricoid cartilage attaches it to the larynx. This is the only complete tracheal ring, the others being incomplete rings of reinforcing cartilage. The trachealis muscle joins the ends of the rings and these are joined vertically by bands of fibrous connective tissue – the annular ligaments of trachea. The epiglottis closes the opening to the larynx during swallowing.

Throat anterior part of the neck, in front of the vertebral column

In vertebrate anatomy, the throat is the front part of the neck, positioned in front of the vertebra. It contains the pharynx and larynx. An important section of it is the epiglottis, which is a flap separating the esophagus from the trachea (windpipe) preventing food and drink being inhaled into the lungs. The throat contains various blood vessels, pharyngeal muscles, the nasopharyngeal tonsil, the tonsils, the palatine uvula, the trachea, the esophagus, and the vocal cords. Mammal throats consist of two bones, the hyoid bone and the clavicle. The "throat" is sometimes thought to be synonymous for the isthmus of the fauces.

Esophageal atresia congenital disorder of digestive system

Esophageal atresia is a congenital medical condition that affects the alimentary tract. It causes the esophagus to end in a blind-ended pouch rather than connecting normally to the stomach. It comprises a variety of congenital anatomic defects that are caused by an abnormal embryological development of the esophagus. It is characterized anatomically by a congenital obstruction of the esophagus with interruption of the continuity of the esophageal wall.

Respiratory tract Organs involved in transmission of air to and from the point where gases diffuse into tissue

In humans, the respiratory tract is the part of the anatomy of the respiratory system involved with the process of respiration. Air is breathed in through the nose or the mouth. In the nasal cavity, a layer of mucous membrane acts as a filter and traps pollutants and other harmful substances found in the air. Next, air moves into the pharynx, a passage that contains the intersection between the esophagus and the larynx. The opening of the larynx has a special flap of cartilage, the epiglottis, that opens to allow air to pass through but closes to prevent food from moving into the airway.

Carina may refer to:

TBI refer to:

Tracheitis inflammation of the trachea

Tracheitis is an inflammation of the trachea. Although the trachea is usually considered part of the lower respiratory tract, in ICD-10 tracheitis is classified under "acute upper respiratory infections".

Terminologia Anatomica (TA) is the international standard on human anatomic terminology. It was developed by the Federative Committee on Anatomical Terminology (FCAT) and the International Federation of Associations of Anatomists (IFAA) and was released in 1998. It supersedes the previous standard, Nomina Anatomica. Terminologia Anatomica contains terminology for about 7500 human gross (macroscopic) anatomical structures. In April 2011, Terminologia Anatomica was published online by the Federative International Programme on Anatomical Terminologies (FIPAT), the successor of FCAT.

The cough reflex has both sensory (afferent) mainly via the vagus nerve and motor (efferent) components. Pulmonary irritant receptors in the epithelium of the respiratory tract are sensitive to both mechanical and chemical stimuli. The bronchi and trachea are so sensitive to light touch that slight amounts of foreign matter or other causes of irritation initiate the cough reflex. The larynx and carina are especially sensitive. Terminal bronchioles and even the alveoli are sensitive to chemical stimuli such as sulfur dioxide gas or chlorine gas. Rapidly moving air usually carries with it any foreign matter that is present in the bronchi or trachea. Stimulation of the cough receptors by dust or other foreign particles produces a cough, which is necessary to remove the foreign material from the respiratory tract before it reaches the lungs.

Bronchopulmonary segment

A bronchopulmonary segment is a portion of lung supplied by a specific tertiary bronchus and arteries. These arteries branch from the pulmonary and bronchial arteries, and run together through the center of the segment. Veins and lymphatic vessels drain along the edges of the segment. The segments are separated from each other by layers of connective tissue. Each bronchopulmonary segment is a discrete anatomical and functional unit, and this separation means that a bronchopulmonary segment can be surgically removed without affecting the function of the others.

Tracheobronchial lymph nodes

The tracheobronchial lymph nodes are lymp nodes that are located around the division of trachea and main bronchi.

Bronchoscopy procedure allowing a physician to look at a patients airways through a thin viewing instrument called a bronchoscope

Bronchoscopy is an endoscopic technique of visualizing the inside of the airways for diagnostic and therapeutic purposes. An instrument (bronchoscope) is inserted into the airways, usually through the nose or mouth, or occasionally through a tracheostomy. This allows the practitioner to examine the patient's airways for abnormalities such as foreign bodies, bleeding, tumors, or inflammation. Specimens may be taken from inside the lungs. The construction of bronchoscopes ranges from rigid metal tubes with attached lighting devices to flexible optical fiber instruments with realtime video equipment.

Spindle cell sarcoma A sarcoma that results in cells that are spindle-shaped. They are usually resistant to radiation therapy.

Spindle cell sarcoma is a type of connective tissue cancer in which the cells are spindle-shaped when examined under a microscope. The tumors generally begin in layers of connective tissue such as that under the skin, between muscles, and surrounding organs, and will generally start as a small lump with inflammation that grows. At first the lump will be self-contained as the tumor exists in its stage 1 state, and will not necessarily expand beyond its encapsulated form. However, it may develop cancerous processes that can only be detected through microscopic examination. As such, at this level the tumor is usually treated by excision that includes wide margins of healthy-looking tissue, followed by thorough biopsy and additional excision if necessary. The prognosis for a stage 1 tumor excision is usually fairly positive, but if the tumors progress to levels 2 and 3, prognosis is worse because tumor cells have likely spread to other locations. These locations can either be nearby tissues or system-wide locations that include the lungs, kidneys, and liver. In these cases prognosis is grim and chemotherapy and radiation are the only methods of controlling the cancer.

A mediastinoscope is a thin, tube-like instrument used to examine the tissues and lymph nodes in the area between the lungs (mediastinum) in a procedure known as mediastinoscopy. These tissues include the heart and its large blood vessels, trachea, esophagus, and bronchi. The mediastinoscope has a light and a lens for viewing and may also have a tool to remove tissue. It is inserted into the chest through a cut above the breastbone.

Bronchogenic cyst Bronchogenic cysts (BCs) are congenital malformations resulting from abnormal budding of the foregut and are most commonly found in the mediastinum

Bronchogenic cysts are small, solitary cysts or sinuses, most typically located in the region of the suprasternal notch or behind the manubrium.

The Intrapulmonary nodes or Lymphatic Vessels of the Lungs originate in two plexuses, a superficial and a deep. The superficial plexus is placed beneath the pulmonary pleura. The deep accompanies the branches of the pulmonary vessels and the ramifications of the bronchi. In the case of the larger bronchi the deep plexus consists of two net-works—one, submucous, beneath the mucous membrane, and another, peribronchial, outside the walls of the bronchi. In the smaller bronchi there is but a single plexus, which extends as far as the bronchioles, but fails to reach the alveoli, in the walls of which there are no traces of lymphatic vessels. The superficial efferents turn around the borders of the lungs and the margins of their fissures, and converge to end in some glands situated at the hilus; the deep efferents are conducted to the hilus along the pulmonary vessels and bronchi, and end in the tracheobronchial lymph nodes. Little or no anastomosis occurs between the superficial and deep lymphatics of the lungs, except in the region of the hilus.

Tracheobronchopathia osteochondroplastica

Tracheobronchopathia osteochondroplastica (TO) is a rare benign disease of unknown cause, in which multiple cartilaginous or bony submucosal nodules project into the trachea and proximal bronchi. The nodules usually spare the posterior wall of the airway because they are of cartilaginous origin, while the posterior wall of the airway is membranous. This is as opposed to tracheobronchial amyloidosis, which does not spare the posterior wall.


  1. Chu CP, Chen PP (April 2002). "Tracheobronchial injury secondary to blunt chest trauma: Diagnosis and management". Anaesth Intensive Care. 30 (2): 145–52. PMID   12002920.

PD-icon.svg This article incorporates  public domain material from the U.S. National Cancer Institute document "Dictionary of Cancer Terms" .

National Cancer Institute US research institute, part of National Institutes of Health

The National Cancer Institute (NCI) is part of the National Institutes of Health (NIH), which is one of eleven agencies that are part of the U.S. Department of Health and Human Services. The NCI coordinates the United States National Cancer Program and conducts and supports research, training, health information dissemination, and other activities related to the causes, prevention, diagnosis, and treatment of cancer; the supportive care of cancer patients and their families; and cancer survivorship.