216
UNIT 2
Covering, Support, and Movement of the Body
7
Table 7.1
Bones of the Skull
BONE COLOR CODE*
COMMENTS
IMPORTANT MARKINGS
Cranial Bones
Frontal
(1)
(Figures 7.4a, 7.5, and 7.7)
Forms forehead, superior part of orbits, and
most of the anterior cranial fossa; contains
sinuses
Supraorbital foramina (notches):
allow the
supraorbital arteries and nerves to pass
Parietal
(2)
(Figures 7.4 and 7.5)
Form most of the superior and lateral aspects
of the skull
Occipital
(1)
(Figures 7.4b, 7.5, 7.6, and 7.7)
Forms posterior aspect and most of the base of
the skull
Foramen magnum:
allows passage of the spinal
cord from the brain stem to the vertebral
canal
Hypoglossal canals:
allow passage of the
hypoglossal nerves (cranial nerve XII)
Occipital condyles:
articulate with the atlas
(first vertebra)
External occipital protuberance
and
nuchal
lines:
sites of muscle attachment
External occipital crest:
attachment site of
ligamentum nuchae
Temporal
(2)
(Figures 7.5, 7.6, 7.7, and 7.8)
Form inferolateral aspects of the skull and
contribute to the middle cranial fossa; have
squamous, tympanic, and petrous parts
Zygomatic process:
helps to form the
zygomatic arch, which forms the prominence
of the cheek
Mandibular fossa:
articular point of the
condylar process of the mandible
External acoustic meatus:
canal leading from
the external ear to the eardrum
Styloid process:
attachment site for several
neck muscles and for a ligament to the hyoid
bone
Mastoid process:
attachment site for several
neck and tongue muscles
Stylomastoid foramen:
allows cranial nerve VII
(facial nerve) to pass
Jugular foramen:
allows passage of the internal
jugular vein and cranial nerves IX, X, and XI
Carotid canal:
allows passage of the internal
carotid artery
Sphenoid
(1)
(Figures 7.4a, 7.5, 7.6, 7.7, and 7.9)
Keystone of the cranium; contributes to the
middle cranial fossa and orbits; main parts
are the body, greater wings, lesser wings, and
pterygoid processes
Sella turcica:
hypophyseal fossa portion is the
seat of the pituitary gland
Optic canals:
allow passage of optic nerves
(cranial nerves II) and the ophthalmic arteries
Superior orbital fissures:
allow passage of
cranial nerves III, IV, VI, part of V (ophthalmic
division), and ophthalmic vein
Foramen rotundum (2)
:
allows passage of the
maxillary division of cranial nerve V
Foramen ovale (2):
allows passage of the
mandibular division of cranial nerve V
Foramen spinosum (2):
allows passage of the
middle meningeal artery
