Fetal Skull

Question 1

compressible, and made mainly of thin pliable tabular(flat) bones forming the vault.

Answer 1

Fetal skull

Question 2

Areas of skull

Answer 2

➢ VERTEX
➢ BROW
➢ FACE

Question 3

It is a quadrangular area
bounded anteriorly by the bregma and coronal suture behind by the lambda and lambdoidal sutures and laterally by lines passing thru the parietal eminences.

Answer 3

Vertex

Question 4

It is an area bounded on one side
by the anterior fontanelle and coronal sutures and on the other side by the root of the nose and supra-orbital ridges of either side.

Answer 4

Brow

Question 5

It is the area bounded by the root of the nose and supra-orbital ridges and on the other, by the junction of the floor of the mouth with neck

Answer 5

Face

Question 6

is the area lying in front of the anterior fontanelle and corresponds to the area of brow.

Answer 6

Sinciput

Question 7

is the area limited to the occipital bone

Answer 7

Occiput

Question 8

Flat bones of the vault are united together by the non-osssified membranes attached to the margins of the bones. These are called???

Answer 8

Sutures

Question 9

lies b/w two parietal bones.

Answer 9

The saggital suture

Question 10

run b/w parietal and frontal bones on either sides.

Answer 10

The coronal sutures

Question 11

lies b/w two frontal bones.

Answer 11

The frontal suture

Question 12

separate the occiput bone and two parietal bones.

Answer 12

Lamboidal suture

Question 13

Digital palpations of sagittal suture during internal examination in labour gives an idea of the

Answer 13

manner of engagement of the head

degree of internal rotation of the head

degree of moulding of the head.

Question 14

Wide gap in the suture line

Answer 14

Fontanelle

Question 15

Formed by joining four sutures in midplane.
● Anteriorly frontal.
● Posteriorly saggital.
● On either side coronal suture.

Answer 15

Anterior fontanelle

Question 16

➢ Diamond like shape.
➢ Floor is made by a
membrane.
➢ Ossified at 18mth after birth.

Answer 16

Anterior fontanelle

Question 17

Importance of anterior fontanelle

Answer 17

• Its palpation thru internal examination denotes the degree of flexion of the head.
• It facilitates the moulding of the head.
• It helps in accomodating the marked brain
growth.
• Palpation reflects intracranial status.

Question 18

Formed by junction of three sutures.
● Saggital suture anteriorly.
● Lambdoidal suture on either side.

Answer 18

Posterior fontanelle

Question 19

➢ Triangular in shape.
➢ Measures about
1.2 1.2cm.
➢ Its floor is membranous but become bony at 3mth.

Answer 19

Posterior fontanelle

Question 20

Importance of posterior fontanelle

Answer 20

It denotes the position of the head in relation to maternal pelvic.

Question 21

9.5cm extends b/w two parietal eminences.

Answer 21

Biparietal diameter

Question 22

8.5cm extends from a point placed below one parietal eminence to a pt. placed above the other parietal eminence of the opposite side.

Answer 22

Super subparietal

Question 23

8cm dist. b/w antero-inferior ends of the coronal suture.

Answer 23

Bi temporal

Question 24

7.5cm dist. b/w tips of the mastoid process.

Answer 24

Bi mastoid

Question 25

It is the alteration of the shape of the forecoming head while passing thru the resistant birth passage during labour.

Answer 25

Moulding

Question 26

Importance of moulding

Answer 26

• Enables head to pass more easily, thru the birth canal.

Question 27

2 parts of skull

Answer 27

1) Neurocranium: •Calvaria (skullcap) •Cranial base (basicranium) 2) Viscerocranium (Facial skeleton)

Question 28

Skull of a term fetus or newborn infant is disproportionately large compared with other parts of the skeleton

Answer 28

Fetal skull

Question 29

Size of skull vs fetal skull

Answer 29

In adult, facial skeleton forms 1/3 of the skull but in the newborn, facial skeleton only forms 1/8 of the skull

Question 30

Smallness of the face is due to

Answer 30

-rudimentary development of the maxillae, mandible and paranasal sinuses –absence of erupted teeth –the small size of the nasal cavities ●Nose lies almost entirely between the orbits ●Orbits appears relatively large

Question 31

At birth, this bone is smooth and unilaminar ( no diploë is present)

Answer 31

Calvaria

Question 32

Characteristics of term fetal skull

Answer 32

1) Mastoid proces is absent 2) Styloid process is absent 3) Stylomastoid foramen is exposed on the lateral surface of the skull 4) Glabella and superciliary arches are not developed 5) Paranasal sinuses are rudimentary or absent 6) External acoustic meatus is short, straight and wholly cartilagenous 7) Ossification is incomplete

Question 33

fibrous joint between flat bones of calvaria

Answer 33

Sutures

Question 34

allow the bones to move during the birth process (moulding)

Answer 34

Sutures

Question 35

allows brain to enlarge during infancy and childhood.

Answer 35

Sutures

Question 36

Important sutures

Answer 36

1) Metopic (frontal) suture 2) Sagittal suture 3) Coronal suture 4) Lambdoidal suture 5) Squamous suture 6) Intermaxillary suture 7) Intermandibular sutures

Question 37

starts to ossify by age of 8

Answer 37

Cranial sutures

Question 38

usually starting between 20 to 30 years , often before the age of 40

Answer 38

Obliteration of cranial sutures

Question 39

usually begins in the coronal suture, and then extends into sagittal and lambdoid sutures

Answer 39

Obliteration

Question 40

premature fusion of cranial sutures

Answer 40

Craniosynostosis

Question 41

Types of craniosynostosis

Answer 41

1) Scaphocephaly (boat head) 2) Brachycephaly (short head) 3) Plagiocephaly (asymmetry head) 4) Trigonocephaly (triangular head) 5) Pansynostosis

Question 42

due to premature closure of sagittal suture

Answer 42

Scaphocephaly

Question 43

premature closure of coronal suture on both sides (bilaterally)

Answer 43

Brachycephaly

Question 44

due to unilateral closure of coronal suture (or lambdoid suture)

Answer 44

Plagiocephaly

Question 45

premature closure of metopic suture

Answer 45

Trigonocephaly (triangular head)

Question 46

premature closure of multiple suture

Answer 46

Pansynostosis

Question 47

Areas of fibrous tissue membrane separating the bones of the calvaria

Answer 47

Fontanelle

Question 48

Major fontanelle

Answer 48

1) Anterior 2) Posterior 3) Anterolateral (Sphenoidal) 4) Posterolateral (Mastoid)

Question 49

Clinical use of fontanelles

Answer 49

- During vaginal examination (during birth) - Degree of hydration - Level of intracranial pressure - To obtain blood sample from underlying superior sagittal sinus - Progress of growth of the frontal and parietal bones

Question 50

are small, irregular and occur at the sphenoidal and mastoid angles of the parietal bones respectively.

Answer 50

The sphenoidal (anterolateral) and mastoid (posterolateral) fontanelle