(kart'ĭ-lăj )

[L. cartilago, gristle]

A specialized type of dense connective tissue consisting of cells embedded in a ground substance or matrix. The matrix is firm and compact; its proteoglycans can store considerably more sodium than plasma can, which in turn allows cartilage to store water, which in turn helps cartilage withstand pressure or impact. Cartilage is bluish-white or gray and is semiopaque; it has no nerve or blood supply of its own. The cells lie in cavities called lacunae. They may be single or in groups of two, three, or four.

Cartilage forms parts of joints in the adult skeleton, such as between vertebral bodies and on the articular surfaces of bones. It also occurs in the costal cartilages of the ribs, in the nasal septum, in the external ear and lining of the eustachian tube, in the wall of the larynx, and in the trachea and bronchi. It forms the major portion of the embryonic skeleton, providing a model in which most bones develop.

alar c.Cartilage forming the broad lateral wall of each nostril.

articular c.The thin layer of smooth, hyaline cartilage located on the joint surfaces of a bone, as in a synovial joint.

costal c.A cartilage that connects the end of a true rib with the sternum or the end of a false rib with the costal cartilage above.

cricoid c.The lowest cartilage of the larynx, shaped like a signet ring, the broad portion being posterior, the anterior portion forming the arch.

SEE: larynx for illus.

cuneiform c.One of two small pieces of elastic cartilage that lie in the aryepiglottic fold of the larynx immediately anterior to the arytenoid cartilage.

elastic c.Cartilage that contains elastin fibers in the matrix. Found in the epiglottis, external ear, and auditory tube, it strengthens these and maintains their shape.

fibrous c.Fibrocartilage.

hyaline c.A bluish-white, glassy, translucent cartilage. The matrix appears homogeneous although it contains collagenous fibers forming a fine network. The walls of the lacunae stain intensely with basic dyes. Hyaline cartilage is flexible and slightly elastic. Its surface is covered by the perichondrium except on articular surfaces. It is found in articular cartilage, costal cartilages, the nasal septum, the larynx, and the trachea.

Jacobson c.

SEE: under Jacobson, Ludwig.

Meckel c.

SEE: under Meckel, Johann Friedrich (the younger).

nasal c.Any of the cartilages forming the principal portion of the subcutaneous framework of the nose.

palpebral c.One of the thin plates of connective tissue resembling cartilage that form the framework of the eyelid.

parachordal c.One of a pair of cartilages in the cephalic portion of the notochord of the embryo that unites in humans to form a single basal plate that is the forerunner of the occipital bone.

Reichert c.

SEE: Reichert cartilage.

semilunar c.One of two crescentic cartilages (medial and lateral) of the knee joint between the femur and tibia.

sesamoid c.One or more small cartilage plates present in fibrous tissue between the lateral nasal and greater alar cartilages of the nose.

shark c.An alternative remedy promoted for the treatment of arthritis and cancer.

thyroid c.The largest and most anterior cartilage of the larynx, consisting of two broad laminae united anteriorly to form a V-shaped structure. It forms a subcutaneous projection called the laryngeal prominence or Adam's apple.

SEE: thyroid gland for illus.

triticeous c.A cartilaginous nodule in the thyrohyoid ligament.

vomeronasal c.One of two narrow strips of cartilage lying along the anterior portion of the inferior border of the septal cartilage of the nose.

Y c.The cartilage that connects the pubis, ilium, and ischium and extends into the acetabulum.