Thyroid cartilage
Encyclopedia
The thyroid cartilage is the largest of the nine cartilage
s that make up the laryngeal skeleton, the cartilage structure in and around the trachea
that contains the larynx
.
It is composed of two plate-like laminae
that fuse on the anterior side of the cartilage to form a peak, called the laryngeal prominence. This prominence is often referred to as the "pomus Adami" or "Adam's apple". The laryngeal prominence is more prominent in adult male than female because of the difference in the size of the angle: 90° in male and 120° in female.
The lip of the thyroid cartilage just superior to the laryngeal prominence is called the superior thyroid notch
, while the notch inferior to the thyroid angle is called the inferior thyroid notch.
Its posterior border is elongated both inferiorly and superiorly to form the superior horn of thyroid cartilage
and inferior horn of thyroid cartilage
.
The posterior edge of each lamina articulates
with the cricoid cartilage inferiorly at a joint called the cricothyroid joint.
Movement of the cartilage at this joint produces a change in tension at the vocal folds, which in turn produces variation in voice
.
The entire superior edge of the thyroid cartilage is attached to the hyoid bone
by the thyrohyoid membrane.
("vocal cords"), which are located directly behind it.
It also serves as an attachment for several laryngeal muscles.
Cartilage
Cartilage is a flexible connective tissue found in many areas in the bodies of humans and other animals, including the joints between bones, the rib cage, the ear, the nose, the elbow, the knee, the ankle, the bronchial tubes and the intervertebral discs...
s that make up the laryngeal skeleton, the cartilage structure in and around the 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...
that contains the larynx
Larynx
The larynx , commonly called the voice box, is an organ in the neck of amphibians, reptiles and mammals involved in breathing, sound production, and protecting the trachea against food aspiration. It manipulates pitch and volume...
.
It is composed of two plate-like laminae
Lamina (anatomy)
Lamina is a general anatomical term meaning "plate" or "layer." It is used in both gross anatomy and microscopic anatomy to describe structures.Some examples include:...
that fuse on the anterior side of the cartilage to form a peak, called the laryngeal prominence. This prominence is often referred to as the "pomus Adami" or "Adam's apple". The laryngeal prominence is more prominent in adult male than female because of the difference in the size of the angle: 90° in male and 120° in female.
The lip of the thyroid cartilage just superior to the laryngeal prominence is called the superior thyroid notch
Superior thyroid notch
Immediately above the laryngeal prominence the laminæ are separated by a V-shaped notch, the superior thyroid notch....
, while the notch inferior to the thyroid angle is called the inferior thyroid notch.
Its posterior border is elongated both inferiorly and superiorly to form the superior horn of thyroid cartilage
Superior horn of thyroid cartilage
The superior horn of thyroid cartilage is long and narrow, directed upward, backward, and medialward, and ends in a conical extremity, which gives attachment to the lateral hyothyroid ligament....
and inferior horn of thyroid cartilage
Inferior horn of thyroid cartilage
The inferior horn of thyroid cartilage is short and thick; it is directed downward, with a slight inclination forward and medialward, and presents, on the medial side of its tip, a small oval articular facet for articulation with the side of the cricoid cartilage....
.
Layers and articulations
The two laminae that make up the main lateral, surfaces of the thyroid cartilage extend obliquely to cover either side of the trachea. The oblique line marks the superior lateral borders of the thyroid gland.The posterior edge of each lamina articulates
Joint
A joint is the location at which two or more bones make contact. They are constructed to allow movement and provide mechanical support, and are classified structurally and functionally.-Classification:...
with the cricoid cartilage inferiorly at a joint called the cricothyroid joint.
Movement of the cartilage at this joint produces a change in tension at the vocal folds, which in turn produces variation in voice
Phonation
Phonation has slightly different meanings depending on the subfield of phonetics. Among some phoneticians, phonation is the process by which the vocal folds produce certain sounds through quasi-periodic vibration. This is the definition used among those who study laryngeal anatomy and physiology...
.
The entire superior edge of the thyroid cartilage is attached to the hyoid bone
Hyoid bone
The hyoid bone is a horseshoe-shaped bone situated in the anterior midline of the neck between the chin and the thyroid cartilage. At rest, it lies at the level of the base of the mandible in the front and the third cervical vertebra behind.Unlike other bones, the hyoid is only distantly...
by the thyrohyoid membrane.
Function
The thyroid cartilage forms the bulk of the anterior wall of the larynx, and serves to protect the vocal foldsVocal folds
The vocal folds, also known commonly as vocal cords, are composed of twin infoldings of mucous membrane stretched horizontally across the larynx...
("vocal cords"), which are located directly behind it.
It also serves as an attachment for several laryngeal muscles.
See also
- CricoidCricoidThe cricoid cartilage, or simply cricoid , is the only complete ring of cartilage around the trachea.-Location:...
- Laryngeal prominence
- LarynxLarynxThe larynx , commonly called the voice box, is an organ in the neck of amphibians, reptiles and mammals involved in breathing, sound production, and protecting the trachea against food aspiration. It manipulates pitch and volume...
- PhonationPhonationPhonation has slightly different meanings depending on the subfield of phonetics. Among some phoneticians, phonation is the process by which the vocal folds produce certain sounds through quasi-periodic vibration. This is the definition used among those who study laryngeal anatomy and physiology...
- Thyroid cartilage reduction
- Vocal fold