The sagittal suture, also known as the interparietal suture and the ''sutura interparietalis'', is a dense, fibrous

connective tissue Connective tissue is one of the four primary types of animal tissue, a group of cells that are similar in structure, along with epithelial tissue, muscle tissue, and nervous tissue. It develops mostly from the mesenchyme, derived from the mesod ...

joint A joint or articulation (or articular surface) is the connection made between bones, ossicles, or other hard structures in the body which link an animal's skeletal system into a functional whole.Saladin, Ken. Anatomy & Physiology. 7th ed. McGraw- ...

between the two

parietal bone The parietal bones ( ) are two bones in the skull which, when joined at a fibrous joint known as a cranial suture, form the sides and roof of the neurocranium. In humans, each bone is roughly quadrilateral in form, and has two surfaces, four bord ...

s of the

skull The skull, or cranium, is typically a bony enclosure around the brain of a vertebrate. In some fish, and amphibians, the skull is of cartilage. The skull is at the head end of the vertebrate. In the human, the skull comprises two prominent ...

. The term is derived from the

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

word ''sagitta'', meaning

arrow An arrow is a fin-stabilized projectile launched by a bow. A typical arrow usually consists of a long, stiff, straight shaft with a weighty (and usually sharp and pointed) arrowhead attached to the front end, multiple fin-like stabilizers c ...

Structure

The sagittal suture is formed from the fibrous

between the two parietal bones of the

. It has a varied and irregular shape which arises during development. The pattern is different between the inside and the outside. Two anatomical landmarks are found on the sagittal suture: the bregma, and the vertex of the skull. The bregma is formed by the intersection of the sagittal and

coronal suture The coronal suture is a dense, fibrous connective tissue joint that separates the two parietal bones from the frontal bone of the skull. Structure The coronal suture lies between the paired parietal bones and the frontal bone of the skull ...

s. The vertex is the highest point on the skull and is often near the midpoint of the sagittal suture.

Development

birth Birth is the act or process of bearing or bringing forth offspring, also referred to in technical contexts as parturition. In mammals, the process is initiated by hormones which cause the muscular walls of the uterus to contract, expelling the f ...

, the bones of the skull do not meet. The gap that remains, which is approximately 5 mm wide, allows for the

brain The brain is an organ (biology), organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It consists of nervous tissue and is typically located in the head (cephalization), usually near organs for ...

to continue to grow normally after birth. The inner parts of the parietal bones fuse before the outer parts.

Clinical significance

If certain bones of the skull grow too fast before birth, then "premature closure" of the sutures may occur. This can cause craniosynostosis, which results in skull deformities. Sagittal craniosynostosis is the most common form. If the sagittal suture closes early the skull becomes long, narrow, and wedge-shaped, a condition called ' scaphocephaly'.

Society and culture

In forensic anthropology, the sagittal suture is one method used to date human remains. The suture begins to close at age twenty nine, starting at where it intersects at the lambdoid suture and working forward. By age thirty five, the suture is completely closed. This means that when inspecting a human skull, if the suture is still open, one can assume an age of less than twenty nine. Conversely, if the suture is completely formed, one can assume an age of greater than thirty five.

History

The term is derived from the Latin word ''sagitta'', meaning ''arrow''. The derivation of this term may be demonstrated by observing how the sagittal suture is notched posteriorly, like an arrow, by the lambdoid suture. The sagittal suture is also known as the 'interparietal suture', the ''sutura interparietalis''.

Additional images

File:Sagittal suture - animation03.gif, Animation. Sagittal suture shown in red. File:Sobo 1909 47 - sagittal suture.png, Sagittal suture seen from inside.

References

Bibliography

Sagittal suture
, ''Stedman's Medical Dictionary'', 27th ed. (2000). *Moore, Keith L., and T.V.N. Persaud. ''The Developing Human: Clinically Oriented Embryology'', 7th ed. (2003).

External links

* * {{Authority control Cranial sutures Human head and neck Joints Joints of the head and neck Skeletal system