TEMPORAL BONE
SIDES FEATURES BORDERS RELATIONS ATTACHMENTS
Temporal bones are situated at the sides and base of skull.
SIDES
• Plate-like squamous part is directed upwards and laterally.
• Strong zygomatic process is directed forwards.
• Petrous part, triangular in shape, is directed medially.
• External acoustic meatus, enclosed between squamous and tympanic parts, is directed
laterally.
FEATURES
It comprises following parts:
Squamous part
Petromastoid part
Tympanic part
Styloid process
Squamous Part
o Two surfaces:Outer and inner
o Two borders: Superior and anteroinferior
Surfaces
Outer or temporal
o It is smooth and forms a part of temporal fossa.
, o Above external acoustic meatus, there is a groove for middle temporal artery.
o Its posterior part presents supramastoid crest. Below the anterior end of
supramastoid crest and posterosuperior to external acoustic meatus, there is
suprameatal triangle.
o Zygomatic process springs forwards from the outer surface of squamous part.
o Its posterior part comprises superior and inferior surfaces.
The inferior surface is bounded by two roots which converge at the tubercle of root
of the zygoma.
o Anterior root projects as the articular tubercle in front of mandibular fossa.
o Posterior root begins above the external acoustic meatus.
o Mandibular fossa lies behind articular tubercle and consists of anterior articular part
formed by squamous part of temporal bone and a posterior non-articular portion
formed by tympanic plate.
Inner or cerebral
o It is concave and shows grooves for the middle meningeal vessels.
o Its superior border articulates with the lower border of parietal bone.
o Its anteroinferior border articulates with the greater wing of sphenoid
Borders
Superior border:
o Articulates with parietal bone.
Anteroinferior border:
o Articulates with greater wing of sphenoid bone.
Petromastoid Part
Mastoid Part Mastoid (Greek breast) part forms posterior part of temporal bone.
It has:
• Two surfaces—outer and inner
• Two borders—superior and posterior, and enclose the mastoid air cells. (The
outer surface forms a downwards projecting conical process, the mastoid
process.)
Surfaces
Outer:
o The outer surface gives attachment to occipitalis muscle.
SIDES FEATURES BORDERS RELATIONS ATTACHMENTS
Temporal bones are situated at the sides and base of skull.
SIDES
• Plate-like squamous part is directed upwards and laterally.
• Strong zygomatic process is directed forwards.
• Petrous part, triangular in shape, is directed medially.
• External acoustic meatus, enclosed between squamous and tympanic parts, is directed
laterally.
FEATURES
It comprises following parts:
Squamous part
Petromastoid part
Tympanic part
Styloid process
Squamous Part
o Two surfaces:Outer and inner
o Two borders: Superior and anteroinferior
Surfaces
Outer or temporal
o It is smooth and forms a part of temporal fossa.
, o Above external acoustic meatus, there is a groove for middle temporal artery.
o Its posterior part presents supramastoid crest. Below the anterior end of
supramastoid crest and posterosuperior to external acoustic meatus, there is
suprameatal triangle.
o Zygomatic process springs forwards from the outer surface of squamous part.
o Its posterior part comprises superior and inferior surfaces.
The inferior surface is bounded by two roots which converge at the tubercle of root
of the zygoma.
o Anterior root projects as the articular tubercle in front of mandibular fossa.
o Posterior root begins above the external acoustic meatus.
o Mandibular fossa lies behind articular tubercle and consists of anterior articular part
formed by squamous part of temporal bone and a posterior non-articular portion
formed by tympanic plate.
Inner or cerebral
o It is concave and shows grooves for the middle meningeal vessels.
o Its superior border articulates with the lower border of parietal bone.
o Its anteroinferior border articulates with the greater wing of sphenoid
Borders
Superior border:
o Articulates with parietal bone.
Anteroinferior border:
o Articulates with greater wing of sphenoid bone.
Petromastoid Part
Mastoid Part Mastoid (Greek breast) part forms posterior part of temporal bone.
It has:
• Two surfaces—outer and inner
• Two borders—superior and posterior, and enclose the mastoid air cells. (The
outer surface forms a downwards projecting conical process, the mastoid
process.)
Surfaces
Outer:
o The outer surface gives attachment to occipitalis muscle.
