FETAL SKULL pptx by Rashmi Goswami (OBG)

FETAL SKULL pptx by Rashmi Goswami (OBG)

• 1.
  FETAL SKULL Presented by:Mrs Rashmi Goswami
• 2.
  Fetal skull is compressibleand made mainly of thin pliable tabular (flat) bones forming the vault.
• 3.
  BONES OF VAULT 1)Two Frontal bones - form the forehead or sinciput. At the centre of each is frontal eminence. 2) Two Parietal bones - lie on either side of the skull. The ossification center of each is called Parietal eminence. 3) Occipital bone - lies at the back of the head and forms the region of the occiput. At the centre it has occipital protuberance.
• 4.
  AREAS OF SKULL •Vertex: It is bounded anteriorly by bregma and coronal sutures, posteriorly by lambda and laboidal suture and lateraly by parietal bones emniences. • Brow/ Sinciput: It is an area bounded on one side by anterior fontanelle and coronal suture and on the other side by the root of the nose and supraorbital ridges. • Face: It is an area bounded on one side by the root of the nose and supraorbital ridges and on the other side by the junction of the floor of the mouth with neck.
• 6.
  SUTURES • Sutures arethe cranial joints and are formed where two bones are adjoin. They are composed of fibrous tissue and allow mobility between the cranial bones. Frontal suture Coronal suture Sagittal suture Lamboid suture
• 7.
  1. Frontal suture: lies between two frontal bones 2. Coronal suture: run between parietal and frontal bones on either side 3. Sagittal suture: lies between two parietal bones. 4. Lamboid suture: separate the occipital bone and two parietal bones.
• 8.
  FONTANELLES • Fontanelles arethe wide gap in the suture line. There are two fontanelles: Anterior fontanelle / Bregma Posterior fontanelle / Lamda
• 9.
  cont... ANTERIOR FONTANELLE (BREGMA) • Location:at the junction of sagittal, coronal and frontal sutures. • Shape: Diamond • Closed: 18 months after birth • Floor: soft membrane POSTERIOR FONTANELLE (LAMBDA) • Location: at the junction of sagittal suture and lamboid suture on either side. • Shape: Triangular • Closed: 6 weeks of age • Floor: bony at term
• 10.
  DIAMETERS ANTERO-POSTERIOR DIAMETERS Sr. no. Diameters Measurementin cm Attitude of the head Presentation 1. Subocciputobregmatic - extends frome the nape of the neck to the centre of the bregma 9.5 cm Flexion Vertex 2. Subocciputofrontal - extends from the nape of the neck to the centre of the sinciput 10 cm Incomplete flexion Vertex 3. Occiputofrontal - extends from the ocipital eminence to the root of the nose (Glabella) 11.5 cm Marked deflexion Vertex 4. Mentovertical - extends from the midpoint of the chin to the highest point of sagittal suture 14 cm Partial extension Brow 5. Submentovertical - extends from the junction of the floor of the mouth to the highest point on the sagittal suture 11.5 cm Incomplete extension Face
• 12.
  TRANSVERSE DIAMETERS 1) Biparietal(9.5 cm) - extends between two parietal eminence. It is the largest transverse diameter in all cephalic presentations. The head is said to be engaged when the biparietal diameter has passed through the pelvic brim. 2) Super-subparietal (8.5 cm) - extends from a point placed below one parietal eminence to a point placed above the other parietal eminence of the opposite side. 3) Bitemporal (8 cm) - distance between the antero-inferior end of coronal suture 4) Bimastoid (7.5 cm) - distance between the tips of the mastoid process.
• 14.
  MOLDING • Molding isthe term applied to the change in shape of the fetal head that takes place during its passage through the birth canal.