The Skull
Pages 120-126 in Textbook
Kyle Franklin
Megan Gleason
Emily Giannotti
Cranial Sutures
• Sutures- lines at which 2 bones fuse together.
These are the 4 on the cranium:
– Coronal Suture- fuses parietal bones to frontal
bone.
– Lambdoidal Suture- fuses occipital bone to
parietal bones (anteriorly).
– Saggital Suture- fuses parietal bones in midline of
skull.
– Squamous Suture- fuses temporal bones to
parietal bones.
Cranial Bones
• The cranium consists of 8 bones (1st 3 are
largest):
– Frontal (1)- forms forehead, projections under
eyebrows, superior part of eye orbits.
– Parietal (2)- form most of superior and lateral
walls of cranium.
Cranial Bones
- Temporal (2)- lie inferior to parietal bones. Contain 5
important markings:
- External auditory meatus- canal that leads to eardrum and
middle ear.
- Styloid process- needlelike projection, inferior to external
auditory meatus, provides for muscle attachment.
- Zygomatic Arch- thin bridge of bone that joins anteriorly
with cheekbone (zygomatic bone).
- Mastoid Process- rough projection, full of air cavities
(mastoid sinuses), provides for muscle attachment.
- Jugular Foramen- medial to styloid process, allows passage
of jugular vein, which drains brain.
Cranial Bones
– Occipital (1)- contains:
• Foramen Magnum- surrounds lower part of brain,
allows spinal cord to connect to brain.
• Occipital Condyles- rest on the first vertebra of the
spinal column.
– Sphenoid (1)- most of this bone lies deep on the
inferior aspect of the cranium.
– Ethmoid (1)- irregular shape, anterior to sphenoid,
forms rook of nasal cavity and part of medial walls
of orbits.
• Christa Galli- projects from superior surface of ethmoid,
outermost covering of brain attaches to it
Facial Bones
• Maxillary- fuses to form upper jaw and all facial
bones except mandible join it.
• Zygomatic- (cheekbones) makes up a good portion of
lateral walls of orbits.
• Lacrimal- (fingernail-sized bones) forms part of
medial walls of orbits and allows passageway for
tears.
• Nasal- small rectangular bone forming the bridge of
the nose.
• Mandible- (lower jaw) largest and strongest facial
bone.
Hyoid Bone
• Not technically part of the skull.
• Only bone in the body that does not articulate
directly with any other bone.
• It is suspended in the mid-neck region.
• Function: moveable base for tongue and attachment
point for the neck muscles that raise and lower the
larynx when we swallow and speak.
References
Beresford, W. (n.d.). 206 Nervous System. Anatomy Department. Retrieved November
18, 2009, from wberesford.hsc.wvu.edu/206CNS.htm
Ph.D., B. B. (2003, December 12). h&n lateral skull - temporal bone - squamous part.
SUNY Upstate Medical University. Retrieved November 17, 2009, from
http://www.upstate.edu/cdb/grossanat/hnsklattb1.shtml
Cummings, B. (n.d.). Use the following blank diagrams. Georgia Highlands College.
Retrieved November 18, 2009, from
http://www.highlands.edu/subwebs/shenderson/API/Blank%20Diagrams/chapter_
7_axial.htm
Lecture 9: Axial Skeleton I. (n.d.). Computing Services for Faculty & Staff. Retrieved
November 17, 2009, from
http://www.rci.rutgers.edu/~uzwiak/AnatPhys/APFallLect9.html
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