Cartilaginous joint Primary cartilaginous joints Primary cartilaginous joint Secondary cartilaginous joints Secondary cartilaginous joint. URL of Article. Primary cartilaginous joint These cartilaginous joints are composed entirely of hyaline cartilage and are known as synchondroses. Examples growth plates synchondroses related to apophyses synchondroses of the pelvis eg. Examples symphysis pubis between the right and left pubic bones manubriosternal joint between the sternal body and the manubrium intervertebral discs sacrococcygeal symphysis.
Quiz questions. Related articles: Anatomy: General. Promoted articles advertising. Figure 1: synchondroses eg. Figure 2: symphyses eg. Figure 3: intervertebral disc Figure 3: intervertebral disc. Figure 4: classification of joints Figure 4: classification of joints. Loading more images Examples of permanent synchondroses are found in the thoracic cage.
One example is the first sternocostal joint, where the first rib is anchored to the manubrium by its costal cartilage. The articulations of the remaining costal cartilages to the sternum are all synovial joints. Additional synchondroses are formed where the anterior end of the other 11 ribs is joined to its costal cartilage. Unlike the temporary synchondroses of the epiphyseal plate, these permanent synchondroses retain their hyaline cartilage and thus do not ossify with age. Due to the lack of movement between the bone and cartilage, both temporary and permanent synchondroses are functionally classified as a synarthrosis.
Fibrocartilage is very strong because it contains numerous bundles of thick collagen fibers, thus giving it a much greater ability to resist pulling and bending forces when compared with hyaline cartilage. This gives symphyses the ability to strongly unite the adjacent bones, but can still allow for limited movement to occur. Thus, a symphysis is functionally classified as an amphiarthrosis.
The gap separating the bones at a symphysis may be narrow or wide. Examples in which the gap between the bones is narrow include the pubic symphysis and the manubriosternal joint. At the pubic symphysis, the pubic portions of the right and left hip bones of the pelvis are joined together by fibrocartilage across a narrow gap. Similarly, at the manubriosternal joint, fibrocartilage unites the manubrium and body portions of the sternum.
The intervertebral symphysis is a wide symphysis located between the bodies of adjacent vertebrae of the vertebral column. Here a thick pad of fibrocartilage called an intervertebral disc strongly unites the adjacent vertebrae by filling the gap between them.
The width of the intervertebral symphysis is important because it allows for small movements between the adjacent vertebrae. In addition, the thick intervertebral disc provides cushioning between the vertebrae, which is important when carrying heavy objects or during high-impact activities such as running or jumping. A synchondrosis is formed when the adjacent bones are united by hyaline cartilage. A temporary synchondrosis is formed by the epiphyseal plate of a growing long bone, which is lost when the epiphyseal plate ossifies as the bone reaches maturity.
The synchondrosis is thus replaced by a synostosis. Permanent synchondroses that do not ossify are found at the first sternocostal joint and between the anterior ends of the bony ribs and the junction with their costal cartilage.
A symphysis is where the bones are joined by fibrocartilage and the gap between the bones may be narrow or wide. A narrow symphysis is found at the manubriosternal joint and at the pubic symphysis. In puberty, increasing levels of estrogen, in both females and males, leads to increased apoptosis of chondrocytes in the epiphyseal plate. Depletion of chondrocytes due to apoptosis leads to less ossification, and growth slows down and later stops when the cartilage has been completely replaced by bone.
This process leaves only a thin epiphyseal scar that later disappears. In adults who have stopped growing, the plate is replaced by an epiphyseal line. Those with achondroplasia a form of dwarfism have premature closure of the epiphyseal growth plates, which results in shorter than average arms and legs.
A symphysis, a type of secondary cartilaginous joint, is a fibrocartilaginous fusion between two bones. It is an amphiarthrosis slightly movable joint, and an area where two parts or structures grow together. Unlike synchondroses, symphyses are permanent. The more prominent symphyses are the pubic symphysis; the symphyses between the bones of the skull, most notably the mandible symphysis menti ; sacrococcygeal symphysis; the intervertebral disc between two vertebrae; and in the sternum, between the manubrium and body, and between the body and xiphoid process.
The pubic symphysis or symphysis pubis is the midline cartilaginous joint secondary cartilaginous uniting the superior rami of the left and right pubic bones. It is a nonsynovial amphiarthrodial joint connected by fibrocartilage, and may contain a fluid-filled cavity. The ends of both pubic bones are covered by a thin layer of hyaline cartilage attached to the fibrocartilage. Symphyses : Diagrammatic section of a symphysis including the ligament, disc of fibrocartilage, and articular cartilage.
The pubic symphysis is located anterior to the urinary bladder and superior to the external genitalia, above the vulva in females and above the penis in males. The suspensory ligament of the penis attaches to the pubic symphysis.
In females, the pubic symphysis is intimately close to the clitoris. In normal adults, it can be moved roughly two mm and with one degree of rotation. Mobility of this joint increases for women at the time of childbirth. During birth, the pubic symphysis of relaxes to slightly widen the birth canal.
This movement is minimal, but along with the compression of the unfused fetal skull generally allows an infant to be born vaginally. The pubic symphysis widens slightly whenever the legs are stretched far apart.
In sports in which this movement is frequent, the risk of a pubic symphysis blockage is high. This injury occurs when the bones at the symphysis do not realign correctly after completion of the movement and get jammed in a dislocated position. The resulting pain can be quite severe, especially if further strain is put upon the affected joint.
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