The cricothyroid ligament (also known as the cricothyroid membrane or cricovocal membrane) is a

ligament A ligament is the fibrous connective tissue that connects bones to other bones. It is also known as ''articular ligament'', ''articular larua'', ''fibrous ligament'', or ''true ligament''. Other ligaments in the body include the: * Peritoneal li ...

in the

neck The neck is the part of the body on many vertebrates that connects the head with the torso. The neck supports the weight of the head and protects the nerves that carry sensory and motor information from the brain down to the rest of the body. In ...

. It connects the cricoid cartilage to the thyroid cartilage. It prevents these cartilages from moving too far apart. It is cut during an emergency cricothyrotomy to treat upper airway obstruction.

Structure

The cricothyroid ligament is composed of two parts: * the median cricothyroid ligament along the midline (a thickening of the cricothyroid membrane). It is a flat band of white

connective tissue Connective tissue is one of the four primary types of animal tissue, along with epithelial tissue, muscle tissue, and nervous tissue. It develops from the mesenchyme derived from the mesoderm the middle embryonic germ layer. Connective tiss ...

that connects the front parts of the contiguous margins of the cricoid and thyroid cartilages. It is a thick and strong ligament, narrow above and broad below. Each lateral ligament is known as the

conus elasticus The cricothyroid ligament (also known as the cricothyroid membrane or cricovocal membrane) is a ligament in the neck. It connects the cricoid cartilage to the thyroid cartilage. It prevents these cartilages from moving too far apart. It is cut dur ...

. * the lateral cricothyroid ligaments on each side (these are also called conus elasticus). Each is overlapped on either side by

laryngeal muscles The larynx (), commonly called the voice box, is an organ in the top of the neck involved in breathing, producing sound and protecting the trachea against food aspiration. The opening of larynx into pharynx known as the laryngeal inlet is about ...

. The conus elasticus (which means elastic cone in Latin) is the lateral portion of the cricothyroid ligament. The lateral portions are thinner and lie close under the mucous membrane of the larynx; they extend from the upper border of the cricoid cartilage to the lower margin of the vocal ligaments, with which they are continuous. The vocal ligaments may therefore be regarded as the free borders of each conus elasticus. They extend from the vocal processes of the

arytenoid cartilage The arytenoid cartilages () are a pair of small three-sided pyramids which form part of the larynx. They are the site of attachment of the vocal cords. Each is pyramidal or ladle-shaped and has three surfaces, a base, and an apex. The arytenoid ...

s to the angle of the thyroid cartilage about midway between its upper and lower borders.

Relations

The prelaryngeal lymph node (also known as the Delphian lymph node) sits anterior to the median cricothyroid ligament.

Function

The cricothyroid ligament prevents the cricoid cartilage and the thyroid cartilage from moving too far apart.

Clinical significance

The cricothyroid ligament is cut during an emergency cricothyrotomy. This kind of surgical intervention is necessary during airway obstruction above the level of vocal folds.

History

The cricothyroid ligament is named after the two structures it connects: the cricoid cartilage and the thyroid cartilage. It is also known as the cricothyroid membrane, and the cricovocal membrane. The various parts of the cricothyroid ligament have been named in many different ways, which can cause confusion.

Other animals

The cricothyroid ligament can be found in many other animals, such as

cats The cat (''Felis catus'') is a domestic species of small carnivorous mammal. It is the only domesticated species in the family Felidae and is commonly referred to as the domestic cat or house cat to distinguish it from the wild members of t ...

dogs The dog (''Canis familiaris'' or ''Canis lupus familiaris'') is a domesticated descendant of the wolf. Also called the domestic dog, it is derived from the extinct Pleistocene wolf, and the modern wolf is the dog's nearest living relative. Do ...

, and

horses The horse (''Equus ferus caballus'') is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of ''Equus ferus''. The horse has evolved over the past 45 to 55 million yea ...

. The trachea can be accessed through the cricothyroid ligament, such as for aspiration. It can be an important landmark.

Additional images

File:Slide5e.JPG, Cricothyroid ligament File:Slide3f.JPG, Cricothyroid ligament File:Slide6lll.JPG, Cricothyroid ligament File:Slide5ooo.JPG, Cricothyroid ligament File:Slide2deded.JPG, Muscles, nerves and arteries of neck.Deep dissection. Anterior view. File:Larynx detailed.jpg, Cricothyroid ligament

References

Ligaments of the head and neck {{Portal bar, Anatomy