2. The inferior view of the skull extends
■ ANTERIORLY: from the middle incisors
■ POSTERIORLY: the superior nuchal lines
■ LATERALLY: to the mastoid process and
3. THE BASE OF THE SKULL IS DIVIDED INTO
■ ANTERIOR PART: includes the teeth and
the hard palate
■ MIDDLE PART: extends from behind the
hard palate to the anterior margin of the
■ POSTERIOR PART: extends from the
anterior edge of the foramen magnum to
the superior nuchal lines.
4. ANTERIOR PART
■ The main features of the anterior part are the:
– teeth and the hard palate.
■ The teeth project from the alveolar
processes of the two maxillae.
■ The hard palate is composed of the
palatine processes of each maxilla
anteriorly and the horizontal plates of each
palatine bone posteriorly.
■ The paired palatine processes of each maxilla
meet in the midline at the intermaxillary suture
■ The paired maxillae and the paired palatine
bones meet at the palatomaxillary suture
■ The paired horizontal plates of each palatine
bone meet in the midline at the interpalatine
5. ADDITIONAL FEATURES IN ANTERIOR PART
■ INCISIVE FOSSA: in the anterior midline, which
contains the incisive foramina (the openings of
the incisive canals, which are passageways
between the hard palate and nasal cavity.
■ GREATER PALATINE FORAMINA: near the
posterolateral border of the hard palate on each
side, which lead to greater palatine canals.
■ LESSER PALATINE FORAMINA: posterior of greater
palatine foramina, in the pyramidal process of
each palatine bone, leading to lesser palatine
■ POSTERIOR NASAL SPINE: a midline pointed
projection in the free posterior border of the hard
6. MIDDLE PART
■ The middle part of the base of the skull is complex forming anterior half and posterior
– ANTERIOR HALF: vomer and sphenoid bones
– POSTERIOR HALF: basilar part of occipital and paired temporal bones
7. MIDDLE PART: ANTERIOR HALF
■ VOMER: in the midline, contributes to the formation of the of the bony nasal
septum separating the two choanae.
■ SPHENOID BONE: made up of body, paired greater and lesser wings, two
pterygoid processes lateral to each choana.
– Three parts of sphenoid: the body, greater wings, and pterygoid processes
are seen in inferior view of skull.
8. SPHENOID BONE
■ BODY: centrally placed, articulates;
– ANTERIORLY with the vomer and palatine
– POSTERIORLY with the occipital bone.
■ PTERYGOID POCESSES: extending downwards,
consists of a narrow medial plate and broader lateral
plate separated by the pterygoid fossa.
– Each medial plate of the pterygoid process ends
inferiorly with a hook like projection the
Pterygoid Hamulus, and divided superiorly to
form shallow scaphoid fossa.
■ GREATER WING: lateral to the lateral pterygoid plate,
articulates laterally and posteriorly with the parts of
– Important features on the surface are the;
9. MIDDLE PART: POSTERIOR HALF
■ CONSISTS OF THE:
occipital and the paired temporal bones.
■ OCCIPITAL BONE: more specifically its basilar part.
– POSTERIORLY: foramen magnum
– LATERALLY: temporal bones.
– Prominent structure on the basilar part of the
occipital bone is a PHARYNGEAL TUBERCLE, a
bony prominence for the attachment of the parts
of pharynx to the base of the skull.
10. POSTERIOR HALF: TEMPORAL BONE
■ The foramen lacerum, an irregular opening filled
with cartilage throughout life.
■ CAROTID CANAL: posterolateral to the foramen
■ PHARYNGOTYMPANIC TUBE: between the petrous
part of temporal and greater wing of sphenoid is a
groove for the auditory tube.
■ MANDIBULAR FOSSA: a concavity where head of
mandible articulates with the base of the skull.
– An imporatant featrure of this articulation is
the prominent articular tubercle, which is the
downward projection of the anterior border of
the mandibular fossa.
11. POSTERIOR PART
■ Extends from anterior edge of the foramen magnum to the superior nuchal lines
CENTRALLY: occipital bone
LATERALLY: temporal bones.
12. POSTERIOR PART: OCCIPITAL BONE
■ It has four parts organized around THE FORAMEN MAGNUM, which is a prominent
feature of this part of skull though which the brain and spinal cord are continuous.
■ PARTS OF OCCIPITAL BONE:
– Squamous part (posterior to foramen magnum)
– Lateral parts (lateral to foramen magnum)
– Basilar part (anterior to foramen magnum)
13. PARTS OF OCCIPITAL BONE
■ EXTERNAL OCCIPITAL CREST: the most visible feature
of squamous part is the, which extends downwards
from the external occipital protuberance towards
■ THE INFERIOR NUCHAL LINES: are laterally from the
midpoint of the crest.
■ THE OCCIPITAL CONDYLES: which are the paired
structures on the border of foramen magnum. They
articulate with the atlas (c1 vertebra).
■ CONDYLAR CANAL: Posterior to each condyle
■ HYPOGLOSSAL CANAL: anterior and superior to each
■ JUGULAR FORAMEN: lateral to each hypoglossal
EXTERNAL OCCIPITAL CREST
INFERIOR NUCHAL LINES
14. PARTS OF TEMPORAL BONE
■ MASTOID BONE: identified by the large cone shaped bony
structure for the attachment of several muscles. On its
deep aspect is the mastoid notch, also for muscle
■ STYLOID PROCESS: anteromedial to mastoid process,
needle shaped. Point of attachment for various muscles
■ Between styloid and mastoid process is the