FirstRanker Logo

FirstRanker.com - FirstRanker's Choice is a hub of Question Papers & Study Materials for B-Tech, B.E, M-Tech, MCA, M.Sc, MBBS, BDS, MBA, B.Sc, Degree, B.Sc Nursing, B-Pharmacy, D-Pharmacy, MD, Medical, Dental, Engineering students. All services of FirstRanker.com are FREE

📱

Get the MBBS Question Bank Android App

Access previous years' papers, solved question papers, notes, and more on the go!

Install From Play Store

Download MBBS The Skull Lecture PPT

Download MBBS (Bachelor of Medicine and Bachelor of Surgery) Latest The Skull Lecture PPT

This post was last modified on 30 November 2021

--- Content provided by‌ FirstRanker.com ---

? Frontal bone
? Parietal bone
? Sphenoid: a) Greater wing b) Lateral pterygoid plate
? Temporal bone: a) Squamous part b) Styloid process c) Mastoid part
? Zygomatic bone

--- Content provided by‌ FirstRanker.com ---

? Maxilla
? Occipital bone
? Nasal bone

NORMA LATERALIS

--- Content provided by‍ FirstRanker.com ---


? Important structures to be identified are:
1. Temporal lines

11.Mastoid foramen

--- Content provided by​ FirstRanker.com ---


2. Supra mastoid crest

12.Temporal fossa

--- Content provided by​ FirstRanker.com ---

3. Zygomatic arch

13.Styloid process

4. External auditory meatus 14.Infra temporal fossa

--- Content provided by‌ FirstRanker.com ---


5. Squamo-tympanic suture 15.Pterygopalatine fossa

6. Supra meatal spine

--- Content provided by‌ FirstRanker.com ---

16.Sphenopalatine foramen

7. Supra meatal triangle

17.Greater palatine canal

--- Content provided by‌ FirstRanker.com ---


8. Parieto-mastoid suture

9. Occipito-mastoid suture

--- Content provided by⁠ FirstRanker.com ---

10.Mastoid process

NORMA LATERALIS

TEMPORAL FOSSA:

--- Content provided by​ FirstRanker.com ---

? Depressed area below the temporal lines.
? Boundaries:
?Anteriorly:

i. Temporal surface of zygomatic process of frontal.

--- Content provided by​ FirstRanker.com ---


ii. Frontal process of zygomatic.

iii. Greater wing of sphenoid.
?Posteriorly:

--- Content provided by⁠ FirstRanker.com ---


i. Posterior part of superior temporal line.

ii. Supra mastoid crest.
?Superiorly: superior temporal line.

--- Content provided by‌ FirstRanker.com ---

?Inferiorly:

i. Laterally: zygomatic arch.

ii. Medially: infratemporal crest.

--- Content provided by FirstRanker.com ---

?Floor gives origin to temporalis muscle.

NORMA LATERALIS

TEMPORAL FOSSA

--- Content provided by‍ FirstRanker.com ---

? Contents:
1. Temporalis muscle

with its fascia.

--- Content provided by FirstRanker.com ---

2. Two deep temporal

nerves.

3. Temporal branches

--- Content provided by FirstRanker.com ---


of maxillary artery.

4. Zygomatico-

--- Content provided by FirstRanker.com ---

temporal nerves.
NORMA LATERALIS
INFRA TEMPORAL FOSSA
? Irregular space situated behind the maxilla and below the zygomatic arch.
? Boundaries:

--- Content provided by FirstRanker.com ---

?Medially:
i. Lateral pterygoid plate.
ii. Pyramidal process of palatine bone
?Anteriorly:
i. Posterior surface of maxilla.

--- Content provided by​ FirstRanker.com ---

ii. Medial surface of zygomatic bone.
?Roof:
i. Infra temporal surface of greater wing to sphenoid.
ii. Squamous part of temporal bone.

--- Content provided by​ FirstRanker.com ---

NORMA LATERALIS

INFRA TEMPORAL FOSSA:
?Above it communicates with temporal fossa.
?It is open on its posterior, lateral and inferior aspects.

--- Content provided by⁠ FirstRanker.com ---

?Laterally ramus of mandible forms its boundary.
?Anterior and medial walls are separated in the upper

part by pterygomaxillary fissure, while they meet below.

--- Content provided by‌ FirstRanker.com ---

?Through pterygomaxillary fissure, this fossa

communicates with the pterygopalatine fossa.


--- Content provided by FirstRanker.com ---

NORMA LATERALIS

INFRA TEMPORAL FOSSA:
? Contents:

--- Content provided by‌ FirstRanker.com ---

1. Muscles:

a) Lateral pterygoid

b) Medial pterygoid

--- Content provided by FirstRanker.com ---


2. Nerves:

a) Mandibular and its branches

--- Content provided by⁠ FirstRanker.com ---

b) Corda tympani

c) Maxillary

3. Vessels:

--- Content provided by⁠ FirstRanker.com ---


a) Maxillary artery and its branches

b) Middle meningeal artery

--- Content provided by⁠ FirstRanker.com ---

c) Maxillary vein.

d) Pterygoid plexus of veins.
NORMA LATERALIS

--- Content provided by FirstRanker.com ---

PTERYGOPALATINE FOSSA:
? Small pyramidal space lying below the apex of the orbit.
? Boundaries:
?Anteriorly: supero-medial part of posterior surface of maxilla.
?Posteriorly: root of pterygoid process and adjoining part of greater wing of

--- Content provided by‌ FirstRanker.com ---


sphenoid.

?Medially: upper part of lateral surface of perpendicular plate of palatine bone

--- Content provided by‌ FirstRanker.com ---

with its orbital and sphenoidal process.

?Roof: formed by under surface of body of sphenoid.
?Floor: formed by meeting of anterior and posterior walls.
?Laterally: It communicates with the infra temporal fossa through

--- Content provided by‌ FirstRanker.com ---


pterygomaxillary fissure.

NORMA LATERALIS
PTERYGOPALATINE FOSSA:

--- Content provided by FirstRanker.com ---

? Communications:
?5 Openings and 2 fissures in this fossa.
?3 openings in the posterior wall. They are:
1. Foramen rotendum
2. Pterygoid canal

--- Content provided by⁠ FirstRanker.com ---

3. Palato-vaginal canal
?On the medial wall is the opening of spheno-platine foramen.
? Greater palatine foramen opens at the place where anterior and posterior walls

meet.

--- Content provided by​ FirstRanker.com ---


?Fissures are: pterygomaxillary fissure and inferior orbital fissure.

NORMA LATERALIS
PTERYGOPALATINE FOSSA:

--- Content provided by​ FirstRanker.com ---

? The fossa communicates with:
1. Infra temporal fossa through pterygomaxillary fissure.
2. Orbital cavity through inferior orbital fissure.
3. Middle cranial fossa through foramen rotendum.
4. Roof of nasal cavity and pharynx through palate-vaginal canal.

--- Content provided by⁠ FirstRanker.com ---

5. Nasal cavity through sphenopalatine foramen.
6. Roof of oral cavity through greater palatine foramen.

NORMA LATERALIS

--- Content provided by FirstRanker.com ---

PTERYGOPALATINE FOSSA:
?Contents:

1. Maxillary artery and its branches.

--- Content provided by‍ FirstRanker.com ---

2. Maxillary nerve in its course to the orbit. The

nerve enters the fossa through foramen rotendum.

3. Pterygopalatine/sphenopalatine ganglion with its

--- Content provided by​ FirstRanker.com ---


branches ( orbital, palatine, nasal and pharyngeal)

4. Pterygoid nerve.

--- Content provided by FirstRanker.com ---


NORMA OCCIPITALIS
NORMA OCCIPITALIS
?Norma occipitalis is convex upwards and on each

--- Content provided by‍ FirstRanker.com ---

side, and is flattened below.

?Bones seen are:
1. Posterior part of parietal bones, above.
2. Upper part of squamous par of the occipital bone

--- Content provided by‌ FirstRanker.com ---


below.

3. Mastoid part of the temporal bone, on each side.
NORMA OCCIPITALIS

--- Content provided by⁠ FirstRanker.com ---

?Sutures seen are:
1. LAMBDOID SUTURE: between the occipital and two

parietal bones.

--- Content provided by⁠ FirstRanker.com ---

2. OCCIPITO MASTOID SUTURE: between the occipital

and mastoid part of temporal bone.

3. PARIETOMASTOID SUTURE: between the parietal bone

--- Content provided by FirstRanker.com ---


and mastoid part of temporal bone.

4. SAGITTAL SUTURE: the posterior part is also seen.

--- Content provided by‍ FirstRanker.com ---



NORMA OCCIPITALIS
EXTERNAL OCCIPITAL

--- Content provided by⁠ FirstRanker.com ---

PROTUBERANCE:
? Is a median prominence

in the lower part of this

--- Content provided by‌ FirstRanker.com ---

norma.

? It marks the junction of

the head and the neck.

--- Content provided by⁠ FirstRanker.com ---


? The most prominent

point on this

--- Content provided by⁠ FirstRanker.com ---

protuberance is called

the inion.


--- Content provided by​ FirstRanker.com ---

NORMA OCCIPITALIS
SUPERIOR NUCHAL

LINES:
? Are curved bony

--- Content provided by‌ FirstRanker.com ---


ridges passing

laterally from the

--- Content provided by‍ FirstRanker.com ---

protuberance.

?These also mark

the junction of the

--- Content provided by‍ FirstRanker.com ---


head and the neck.


NORMA OCCIPITALIS

--- Content provided by‌ FirstRanker.com ---

HIGHEST NUCHAL LINES:

? Are not always present.

? They are curved bony

--- Content provided by⁠ FirstRanker.com ---


ridges situated 1 cm

above the superior

--- Content provided by‍ FirstRanker.com ---

nuchal lines.

? They begin from the

upper part of the

--- Content provided by‍ FirstRanker.com ---


external occipital

protuberance.

--- Content provided by FirstRanker.com ---

? Are more arched than

the superior nuchal lines.
NORMA OCCIPITALIS
OCCIPITAL POINT:

--- Content provided by⁠ FirstRanker.com ---

?It is a median

point a little

above the inion.

--- Content provided by‍ FirstRanker.com ---


?It is the point

farthest from the

--- Content provided by​ FirstRanker.com ---

glabella.


NORMA OCCIPITALIS
THE MASTOID FORAMEN:

--- Content provided by‍ FirstRanker.com ---

? Located on the mastoid

part of temporal bone at

or near the

--- Content provided by‌ FirstRanker.com ---


occipitomastoid suture.

? Internally, it opens at the

--- Content provided by⁠ FirstRanker.com ---

sigmoid sulcus.

? The mastoid foramen

transmits an emissary

--- Content provided by FirstRanker.com ---


vein and the meningeal

branch of occipital artery.
NORMA OCCIPITALIS

--- Content provided by‍ FirstRanker.com ---

ATTACHMENTS:
1. External occipital protuberance:
a) Upper part gives origin to the trapezius
b) Lower part gives attachment to upper end of the ligamentum nuchae.
2. Superior nuchal lines:

--- Content provided by FirstRanker.com ---

a) Medial 1/3- gives origin to trapezius.
b) Lateral part provides insertion to sternocleidomastoid above and splenius

capitis below.

--- Content provided by‌ FirstRanker.com ---

3. Highest nuchal lines: (if present)
a) Provides attachment to epicranial aponeurosis medially.
b) Gives origin to occipitalis or occipital belly of occipitofrontalis muscle laterally.
* In case the highest nuchal lines are absent, these structures are attached to the

--- Content provided by‌ FirstRanker.com ---

superior nuchal lines.


NORMA OCCIPITALIS

--- Content provided by⁠ FirstRanker.com ---


Epicranial aponeurosis

Occipital belly of occipitofrontalis

--- Content provided by‍ FirstRanker.com ---

muscle.