The cricothyroid ligament (also known as the cricothyroid membrane or cricovocal membrane) is a ligament 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 The cricoid cartilage , or simply cricoid (from the Greek ''krikoeides'' meaning "ring-shaped") or cricoid ring, is the only complete ring of cartilage around the trachea. It forms the back part of the voice box and functions as an attachment si ...

to the

thyroid cartilage The thyroid cartilage is the largest of the nine cartilages that make up the ''laryngeal skeleton'', the cartilage structure in and around the trachea that contains the larynx. It does not completely encircle the larynx (only the cricoid cartilag ...

. It prevents these cartilages from moving too far apart. It is cut during an emergency

cricothyrotomy A cricothyrotomy (also called cricothyroidotomy) is an incision made through the skin and cricothyroid membrane to establish a patent airway during certain life-threatening situations, such as airway obstruction by a foreign body, angioedema, or ...

to treat upper

airway obstruction Airway obstruction is a blockage of respiration in the airway that hinders the free flow of air. It can be broadly classified into being either in the upper airway (UPA) or lower airway (LOA). Airway obstruction is a life-threatening condition ...

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 tissue ...

that connects the front parts of the contiguous margins of the

cricoid The cricoid cartilage , or simply cricoid (from the Greek ''krikoeides'' meaning "ring-shaped") or cricoid ring, is the only complete ring of cartilage around the trachea. It forms the back part of the voice box and functions as an attachment si ...

and

s. 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 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 A mucous membrane or mucosa is a membrane that lines various cavities in the body of an organism and covers the surface of internal organs. It consists of one or more layers of epithelial cells overlying a layer of loose connective tissue. It i ...

of the larynx; they extend from the upper border of the cricoid cartilage to the lower margin of the

vocal ligament In humans, vocal cords, also known as vocal folds or voice reeds, are folds of throat tissues that are key in creating sounds through vocalization. The size of vocal cords affects the pitch of voice. Open when breathing and vibrating for speech ...

s, 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 process In the human larynx, the vocal process is the anterior angle of the base of the arytenoid cartilage, as it projects horizontally forward and gives attachment to the vocal ligament. The arytenoids are paired cartilages with a medial and a latera ...

es of the arytenoid cartilages 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

and the

from moving too far apart.

Clinical significance

The cricothyroid ligament is cut during an emergency

. This kind of surgical intervention is necessary during

above the level of

vocal folds In humans, vocal cords, also known as vocal folds or voice reeds, are folds of throat tissues that are key in creating sounds through vocalization. The size of vocal cords affects the pitch of voice. Open when breathing and vibrating for speech ...

History

The cricothyroid ligament is named after the two structures it connects: the

and the

. 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 ...

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 relativ ...

, 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 ...

. The

trachea The trachea, also known as the windpipe, is a cartilaginous tube that connects the larynx to the bronchi of the lungs, allowing the passage of air, and so is present in almost all air-breathing animals with lungs. The trachea extends from th ...

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