The costochondral joints are the
joints between the
rib
In vertebrate anatomy, ribs ( la, costae) are the long curved bones which form the rib cage, part of the axial skeleton. In most tetrapods, ribs surround the chest, enabling the lungs to expand and thus facilitate breathing by expanding the ches ...
s and
costal cartilage in the front of the
rib cage. They are
hyaline
A hyaline substance is one with a glassy appearance. The word is derived from el, ὑάλινος, translit=hyálinos, lit=transparent, and el, ὕαλος, translit=hýalos, lit=crystal, glass, label=none.
Histopathology
Hyaline cartilage is ...
cartilaginous joints (i.e.
synchondrosis
A synchondrosis (or primary cartilaginous joint) is a type of cartilaginous joint where hyaline cartilage completely joins together two bones. Synchondroses are different than symphyses (secondary cartilaginous joints) which are formed of fibroc ...
or primary cartilagenous joint). Each rib has a depression shaped like a cup that the costal cartilage articulates with. There is normally no movement at these joints. Joints between costal cartilages of the sixth and
ninth rib are plane
synovial joint
A synovial joint, also known as diarthrosis, joins bones or cartilage with a fibrous joint capsule that is continuous with the periosteum of the joined bones, constitutes the outer boundary of a synovial cavity, and surrounds the bones' articulat ...
s. Articulation between costal cartilage of the ninth rib and
tenth rib
The rib cage, as an enclosure that comprises the ribs, vertebral column and sternum in the thorax of most vertebrates, protects vital organs such as the heart, lungs and great vessels.
The sternum, together known as the thoracic cage, is a semi-r ...
is fibrous.
The lateral end of each costal cartilage is received into a depression in the sternal end of the rib, and the two are held together by the
periosteum.
References
Skeletal system
Thorax (human anatomy)
Joints
{{musculoskeletal-stub