FETAL SKULL

 

The Eight Bones that form the cranium frontal (1), Parietal (2) Temporal (2), Occipipital (1) Sphenoid (1) Ethnocide (1)

Sutures:-

The Sagittal or longitudinal suture-  b/w two partial bones

The coronal sutures-  b/w parietal & frontal bones on either side.

The frontal sutures- b/w two frontal bones

The labroid sutures – separate the occipital bone & two parietal bones

Importance:-

It permits gliding movement of one bone over the other during molding of the head.

A phenomenon of significance while hard passes through the pelvic during labor

Digital palpation of sagittal suture during internal examination

(In labor gives an idler of the manner of engagement of hard)

Degree of internal rotation of head & degree of molding of the head.

Fontanel’s:-

Wide gap in the suture line is called foritanelles

The Six fortuneless in number two are of obstetric significance

(1) Anterior fontanels or breams (ii) Posterior fontanels or Lambda

(1) Anterior fontanels:-

It is formed by joining of the four sutures

The sutures are interiorly frontal, posterior sagittal on either side coronal.

The shape is like diamond, (Ossified 18 month after birth)

Importance:-

Its palpation through internal examination the degree of flexion of head 

It facilitates molding of the head

It helps in accommodating the marked brain growth.

Brain double its size during first year of life.

Palpation of the floor reflects intracranial status.

Collection of blood and exchange transfusing (on rase location )

CSF can be drawn

(2) Posterior fontanellsa:-

It is formed by junction of three suture

Sagittal suture interiorly and labroid suture on either side

It is triangular in shape (1.2 x 1.2 cm) (cloze 1 to 1Year 6 month)

Importance:- It denotes the position of the head in sensation to maternal pelvis.

Diameters of skull:-

The engaging diameter of the skull depends on the degree of flexion present….

Diameters Attitude of head Presentation

(i)Sub-occipital-pragmatic (9.5 cm) Complete flexion Vertex

(nape of the neck to the centre of the Bergman)

(ii) Sub-occipital frontal (10 cm) Incomplete flexion Vertex

(nape of the neck to the anterior end Of the anterior fontanels or entre of incipit)

(iii) Occipital-frontal (11.5) Marked defluxion Vertex

(Occipital eminence to the root of the nose)

(iv) Men to-vertical (14 cm) Partial extension Born

(Mid point of the chin to the Highest point on the sagittal suture)

(v) Sub men to- Vertical (11.5 cm) Incomplete extension Face

(Junction floor of the mouth and neck to the highest point on the sagittal suture)

(vi) Sub men to- pragmatic (9.5 cm) Complete extension Face

(Extends from junction floor the Mouth and neck to the centre of the brogan)

The transverse diameter which are concerned in the Mechanism of Labor

(i) Bi- Mastoid diameter (7.5 cm):-

It is the distance b/w tips of the mastoid processes.

The diameter is Incompressible & Impossible to seduce Length

(ii) Bi-temporal diameter (8 cm):-

It is distance b/w temporal bone

(iii) Super-Sub partial (8.5 cm)

Extend from below parietal eminence

(iv) Bi-parietal diameter (9.5 cm)

Extends b/w two parietal eminences