Fontanelle

Information about Fontanelle

This article is about the human anatomical feature. For other uses, see Fontanelle (disambiguation).
Enlarge picture
The skull at birth, showing the anterior and posterior fontanelles.
Enlarge picture
The skull at birth, showing the lateral fontanelle.
In human anatomy, a fontanelle (or fontanel) is one of two "soft spots" on a newborn human's skull. There are, however, two more fontanelles of interest, the mastoid fontanelle, and the sphenoidal fontanelle.

Fontanelles are soft spots on a baby's head which, during birth, enable the soft bony plates of the skull to flex, allowing the head to pass through the birth canal. Fontanelles are usually completely hardened by a child's second birthday, and will eventually form the sutures of the neurocranium.

The skull of a newborn consists of five main bones: two frontal bones, two parietal bones, and one occipital bone. These are joined by fibrous sutures, which allow movement that facilitates childbirth and brain growth.

At birth, the skull features a small posterior fontanelle, an open area covered by a tough membrane, where the two parietal bones adjoin the occipital bone (at the lambda). This fontanelle usually closes during the first several months of an infant's life.

There is also a much larger, diamond-shaped anterior fontanelle where the two frontal and two parietal bones abut. This fontanelle remains open until the child is about two years of age. In cleidocranial dysostosis it is often late in closing or never closes.

The anterior fontanelle is useful clinically. Examination of an infant includes palpating the anterior fontanelle. A sunken fontanelle indicates dehydration, whereas a very tense or bulging anterior fontanelle indicates raised intracranial pressure.

Parents may worry that their infant may be more prone to injury at the fontanelles. In fact, although they may colloquially be called "soft-spots", the membrane covering the fontanelles is extremely tough and difficult to penetrate.

The fontanelles allow the infant brain to be imaged using ultrasonography. Once they are closed, most of the brain is inaccessible to ultrasound imaging, as the bony skull presents an acoustic barrier.

References

 •  • [ e]
Bones of head and neck: cranial sutures, fontanelles, and related regions
Cranial suturesCoronal - Lambdoid - Occipitomastoid - Sphenofrontal - Sphenoparietal - Sphenosquamosal - Sphenozygomatic -Squamosal - Zygomaticotemporal - Zygomaticofrontal - Frontal/Metopic - Sagittal - Frontoethmoidal - Petrosquamous - Sphenoethmoidal - Sphenopetrosal
FontanellesAnterior fontanelle - Posterior fontanelle
Foramina of multiple bonesInferior orbital fissure - Foramen lacerum - Jugular foramen - Nasolacrimal canal
FossaeAnterior cranial fossa - Middle cranial fossa - Posterior cranial fossa - Cranial cavity
Other compound structuresAsterion - Nasion - Pterion - Dacryon - Zygomatic arch - Calvaria - Temporal fossa - Infratemporal fossa - Stephanion - Pterygomaxillary fissure - Pterygopalatine fossa
A fontanelle is a hole in the braincase of a skull.

Fontanelle may also refer to:
  • Fontanelle, Iowa, a city in the state of Iowa
  • Fontanelle (TV), a town in Italy
  • Fontanelle, Nebraska, an unincorporated area in Nebraska

..... Click the link for more information.
Human anatomy is primarily the scientific study of the morphology of the adult human body.[1] It is subdivided into gross anatomy and microscopic anatomy.[1]
..... Click the link for more information.
Editing of this page by unregistered or newly registered users is currently disabled due to vandalism.
If you are prevented from editing this page, and you wish to make a change, please discuss changes on the talk page, request unprotection, log in, or .
..... Click the link for more information.
Editing of this page by unregistered or newly registered users is currently disabled due to vandalism.
If you are prevented from editing this page, and you wish to make a change, please discuss changes on the talk page, request unprotection, log in, or .
..... Click the link for more information.
skull is a bony structure found in many animals which serves as the general framework for the head. The skull supports the structures of the face and protects the head against injury.

The skull can be subdivided into two parts: the cranium and the mandible.
..... Click the link for more information.
The frontal bone is a bone in the human skull that resembles a cockleshell in form, and consists of two portions:
  • a vertical portion, the squama frontalis, corresponding with the region of the forehead.

..... Click the link for more information.
The parietal bones are bones in the human skull and form, by their union, the sides and roof of the cranium. Each bone is irregularly quadrilateral in form, and has two surfaces, four borders, and four angles.

Surfaces

External

The external surface [Fig.
..... Click the link for more information.
The occipital bone, a saucer-shaped membrane bone situated at the back and lower part of the cranium, is trapezoid in shape and curved on itself. It is pierced by a large oval aperture, the foramen magnum, through which the cranial cavity communicates with the vertebral canal.
..... Click the link for more information.
Cranial sutures are the joints between the bones of the skull (or "cranium"), bound together by Sharpey's fibres. A tiny amount of movement is permitted at sutures, which contributes to the compliance and elasticity of the skull.
..... Click the link for more information.
Childbirth (also called labour, birth, partus or parturition) is the culmination of a human pregnancy or gestation period with the delivery of one or more newborn infants from a woman's uterus.
..... Click the link for more information.
In animals, the brain or encephalon (Greek for "in the skull"), is the control center of the central nervous system, responsible for behavior. The brain is located in the head, protected by the skull and close to the primary sensory apparatus of vision, hearing,
..... Click the link for more information.
The term cell growth is used in two different ways in biology.

When used in the context of reproduction of living cells the phrase "cell growth" is shorthand for the idea of "growth in cell populations by means of cell reproduction.
..... Click the link for more information.
The posterior fontanelle (or occipital fontanelle) is triangular in form and is situated at the junction of the sagittal suture and lambdoidal suture.

External links

  • NIC25 at FPnotebook
  • -1684406221 at GPnotebook

..... Click the link for more information.
See also:
A biological membrane or biomembrane is an enclosing or separating tissue which acts as a barrier within or around a cell.
..... Click the link for more information.
Lambda (uppercase Λ, lowercase λ) is the 11th letter of the Greek alphabet. In the system of Greek numerals it has a value of 30. Letters that arose from Lambda include the Roman L and the Cyrillic letter El (Л, л).
..... Click the link for more information.
The anterior fontanelle (bregmatic fontanelle, frontal fontanelle) is the largest, and is placed at the junction of the sagittal suture, coronal suture, and frontal suture; it is lozenge-shaped, and measures about 4 cm in its antero-posterior and 2.
..... Click the link for more information.
MeSH D002973 Cleidocranial dysostosis or Cleidocranial dysplasia is a hereditary congenital abnormality of humans due to haploinsufficiency caused by mutations in the CBFA1 gene.
..... Click the link for more information.
Dehydration
Classification & external resources

ICD-10 E 86.
ICD-9 276.5

Dehydration (hypohydration) is the removal of water (hydro in ancient Greek) from an object.
..... Click the link for more information.
Intracranial pressure, (ICP), is the pressure exerted by the cranium on the brain tissue, cerebrospinal fluid (CSF), and the brain's circulating blood volume. ICP is a dynamic phenomenon constantly fluctuating in response to activities such as exercise, coughing, straining,
..... Click the link for more information.
Medical ultrasonography (sonography) is an ultrasound-based diagnostic imaging technique used to visualize muscles and internal organs, their size, structures and possible pathologies or lesions.
..... Click the link for more information.
Bones are rigid organs that form part of the endoskeleton of vertebrates. They function to move, support, and protect the various organs of the body, produce red and white blood cells and store minerals.
..... Click the link for more information.
Head and neck anatomy focuses on the structures of the head and neck of the human body, including the brain, bones, muscles, blood vessels, nerves, glands, nose, mouth, teeth, tongue, and throat.
..... Click the link for more information.
Cranial sutures are the joints between the bones of the skull (or "cranium"), bound together by Sharpey's fibres. A tiny amount of movement is permitted at sutures, which contributes to the compliance and elasticity of the skull.
..... Click the link for more information.
Cranial sutures are the joints between the bones of the skull (or "cranium"), bound together by Sharpey's fibres. A tiny amount of movement is permitted at sutures, which contributes to the compliance and elasticity of the skull.
..... Click the link for more information.
The coronal suture is a dense, fibrous connective tissue joint that separates the frontal and parietal bones of the skull. At birth, the bones of the skull do not meet.

Pathology

If certain bones of the skull grow too fast then "premature closure" of the sutures may occur.
..... Click the link for more information.
The lambdoid suture (or Lambdoidal suture) is a dense, fibrous connective tissue joint that separates the parietal and temporal bones of the skull from the occipital bone.

Its name comes from the lambda-like shape this suture makes on the back of the skull.
..... Click the link for more information.
The occipitomastoid suture is the cranial suture between the occipital bone and the mastoid portion of the temporal bone.

It is continuous with the lambdoidal suture.
..... Click the link for more information.
The Sphenofrontal suture is the cranial suture between the sphenoid bone and the frontal bone.

Additional images



The skull from the front.

Base of the skull. Upper surface.

..... Click the link for more information.
The Sphenoparietal suture is the cranial suture between the sphenoid bone and the parietal bone.

External links

  • SIG at UWash Sphenoparietal%20suture
This article was originally based on an entry from a public domain edition of Gray's Anatomy.
..... Click the link for more information.
The Sphenosquamosal suture is a cranial suture between the sphenoid bone and the squama of the temporal bone.

Additional images



Base of the skull. Upper surface.

..... Click the link for more information.

This article is copied from an article on Wikipedia.org - the free encyclopedia created and edited by online user community. The text was not checked or edited by anyone on our staff. Although the vast majority of the wikipedia encyclopedia articles provide accurate and timely information please do not assume the accuracy of any particular article. This article is distributed under the terms of GNU Free Documentation License.