There are two types of cartilaginous joints. 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. A wide symphysis is the intervertebral symphysis in which the bodies of adjacent vertebrae are united by an intervertebral disc.
symphysis
type of cartilaginous joint where the bones are joined by fibrocartilage
synchondrosis
type of cartilaginous joint where the bones are joined by hyaline cartilage
Go to this website to view a radiograph (X-ray image) of a child’s hand and wrist. The growing bones of child have an epiphyseal plate that forms a synchondrosis between the shaft and end of a long bone. Being less dense than bone, the area of epiphyseal cartilage is seen on this radiograph as the dark epiphyseal gaps located near the ends of the long bones, including the radius, ulna, metacarpal, and phalanx bones. Which of the bones in this image do not show an epiphyseal plate (epiphyseal gap)?
Although they are still growing, the carpal bones of the wrist area do not show an epiphyseal plate. Instead of elongating, these bones grow in diameter by adding new bone to their surfaces.
1. A cartilaginous joint ________.
A) has a joint cavity
B) is called a symphysis when the bones are united by fibrocartilage
C) anchors the teeth to the jaws
D) is formed by a wide sheet of fibrous connective tissue
B
2. A synchondrosis is ________.
A) found at the pubic symphysis
B) where bones are connected together with fibrocartilage
C) a type of fibrous joint
D) found at the first sternocostal joint of the thoracic cage
D
3. Which of the following are joined by a symphysis?
A) adjacent vertebrae
B) the first rib and the sternum
C) the end and shaft of a long bone
D) the radius and ulna bones
A
4. The epiphyseal plate of a growing long bone in a child is classified as a ________.
A) synchondrosis
B) synostosis
C) symphysis
D) syndesmosis
A
1. Describe the two types of cartilaginous joints and give examples of each.
Cartilaginous joints are where the adjacent bones are joined by cartilage. At a synchondrosis, the bones are united by hyaline cartilage. The epiphyseal plate of growing long bones and the first sternocostal joint that unites the first rib to the sternum are examples of synchondroses. At a symphysis, the bones are joined by fibrocartilage, which is strong and flexible. Symphysis joints include the intervertebral symphysis between adjacent vertebrae and the pubic symphysis that joins the pubic portions of the right and left hip bones.
2. Both functional and structural classifications can be used to describe an individual joint. Define the first sternocostal joint and the pubic symphysis using both functional and structural characteristics.
The first sternocostal joint is a synchondrosis type of cartilaginous joint in which hyaline cartilage unites the first rib to the manubrium of the sternum. This forms an immobile (synarthrosis) type of joint. The pubic symphysis is a slightly mobile (amphiarthrosis) cartilaginous joint, where the pubic portions of the right and left hip bones are united by fibrocartilage, thus forming a symphysis.