NORMA LATERALIS
Topic - NORMA LATERALIS
Department of human
anatomy BONES
FRONTAL
PARIENTAL
OCCIPITAL
TEMPORAL
SPHENOID
ZYGOMATIC
FEATURES TEMPORAL LINES
The temporal lines have been studied in the norma verticalis. The inferior temporal line, in its posterion part, turns downwards & forewards & becomes continues with the supramastoid crest on the squamous temporal bone near its junction with the mastoid temporal.this crest is continuous ant. with the
Zygomatic arch or zygoma
The zygomatic arch is a horizontal on the side of the head, in front of the ear, a little above the tragus. It is formed by the temporal process of the zygomatic bone is ant. one- third & the zygomatic process of the temporal bone in post. two –thirds. The zygomatico-
External acoustic meatus
The external acoustic meatus opens just below the post. part of the posterior root of zygoma, its ant. & inferior margin are formed by the tympanic plates, & the posterosuperior
Masteriod part of the temporal bone
The mastoid part of the temporal bone lies just behind the external acoustic meatus. It is continuous antero- superiorly with the squamous temporal bone.
The mastoid temporal bone articulates postero- sup. with the posterinferior part of the parietal
bone at the horizontal parietomastoid suture,&
post. with the squamous occipital bone at theThe asterion is the point where the parietomastoid , occipitomastoid & lambdoid suture meet. The mastoid process is a breast like projection from the lower part of the mastoid temporal bone, postero-inferior to the external acoustic meatus. It appears during the second year of life. The mastoid foramen
Styloid process
The styloid process is a needle – like thin , long projection from the norma basalis situated anteromedial to the mastoid process. Temporal fossa Boundaries Above – by the superior temporal line.
Below – by the upper border of the zygomatic
arch laterally, & by the infratemporal crest
of the greater wing of the sphenoid bone medially.Anterior wall - is formed by the zygomatic bone
floor
The ant. part of the floor is crossed by an H- shaped suture where four bones, frontal, parietal, greater wing of sphenoid & temporal adjoin each other.
This area is termed the pterion. It lies 4 cm above the midpoint of the Infratemporal fossa It is an irregular space below zygomatic arch.
Boundaries post. Surface of body of maxilla. Ant. –
infratemporal surface of greater wing of
Roof – sphenoid.
lateral pterygoid plate & pyramidal
Medial – Pterygopalatine fossa This is small pyramidal space situated deeply, below the apex of the orbit.
Attachments
1. The temporal fascia is attached to the superior
temporal line & to the area between the two
temporal lines.2. The medial surface & lower border of the zygomatic arch give origin to the masseter.
3. The gap between the zygomatic arch & the side
Structure passing through
foramina1. The tympanomastoid fissure on the ant.
aspect of the base of the mastoid process transmits the auricular branch of vagus nerve.
2. The mastoid foramen transmits :-
a) An emissary vein connecting the sigmoid sinus with the post. auricular
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