The posterior fontanelle (lambdoid fontanelle, occipital fontanelle) is a gap between bones in the human skull (known as
fontanelle
A fontanelle (or fontanel) (colloquially, soft spot) is an anatomical feature of the infant human skull comprising soft membranous gaps ( sutures) between the cranial bones that make up the calvaria of a fetus or an infant. Fontanelles allow f ...
), triangular in form and situated at the junction of the
sagittal suture
The sagittal suture, also known as the interparietal suture and the ''sutura interparietalis'', is a dense, fibrous connective tissue joint between the two parietal bones of the skull. The term is derived from the Latin word ''sagitta'', meanin ...
and
lambdoidal suture
The lambdoid suture (or lambdoidal suture) is a dense, fibrous connective tissue joint on the posterior aspect of the skull that connects the parietal bones with the occipital bone. It is continuous with the occipitomastoid suture.
Structure
T ...
. It generally closes in 6–8 weeks from birth. The cranial point in adults corresponding the fontanelle is called 'lambda' A delay in closure is associated with congenital
hypothyroidism
Hypothyroidism (also called ''underactive thyroid'', ''low thyroid'' or ''hypothyreosis'') is a disorder of the endocrine system in which the thyroid gland does not produce enough thyroid hormone. It can cause a number of symptoms, such as po ...
.
See also
*
Lambda (anatomy)
The lambda is the meeting point of the sagittal suture and the lambdoid suture. This is also the point of the occipital angle. It is named after the Greek letter lambda.
Structure
The lambda is the meeting point of the sagittal suture and t ...
References
Skull
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