Transcript Axial Skeleton - The Skull

Axial Skeleton
Bones of the Skull
The Skull: Two Sets of Bones
• The Cranium:
• Facial:
Cranium = 3 Sutures
Three
Sutures
• Coronal
• Sagittal
• Lamboidal
Cranium = 8 Bones
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Frontal = 1
Parietal = 2
Temporal = 2
Occipital = 1
Sphenoid = 1
Ethmoid = 1
Frontal = #1(single)
Parietal = #2 (Pair)
Temporal = #4 (pair)
Bone Markings of the Temporal
Bone
External Acoustic
Meatus
• Canal that leads to
the eardrum
Bone Markings of the Temporal
Bone
Styloid Process
• Needle-like projection
• The site of muscle
attachment for many
neck muscles
Bone Markings of the Temporal
Bone
Zygomatic Arch
• The bridge that
joins with the
cheek bone
Bone Markings of the Temporal
Bone
Mastoid Process
Rough projection
posterior and inferior
to the acoustic
meatus
Filled with air cavaties
called mastoid
sinuses
Attachment site for neck
muscles
Bone Markings of the Temporal
Bone
• Openings:
• Jugular
Foramen
• Carotid Canal
Occipital = #3 (single)
Bone Markings of the Occipital
Bone
• Foramen
Magnum
• Large opening
that allows the
spinal cord to
connect with
the brain
Bone Markings of the Occipital
Bone
• Occipital
Condyles
• Rest on the
first vertebra
of the spinal
column
Sphenoid
• Butterfly shaped, spans the width of the skull
Markings of the Sphenoid
• Stella Turcica:
“Turk’s Saddle”
that holds the
pituitary gland
• Foramen Ovale:
Oval opening that
allows Cranial
Nerve V to pass
to the chewing
muscle
Ethmoid
Features of the Ethmoid
• Crista Galli:
“Cock’s Comb”
where the brain
covering attaches
• Cribiform Plate:
Nerves carrying
olfactory receptors
Extensions of Ethmoid Bone
• Superior and Middle
Nasal Conchae
• Form lateral walls of
the nasal cavity
Facial Bones
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Maxillae (2 Fused)
Palatine (Paired)
Zygomatic
Lacrimal
Nasal
Vomer
Inferior Nasal
Conchae
• Mandible
Maxillae
• Upper Jaw
• All facial bones
except the mandible
join the maxillae
• Carry the upper teeth
Palatine Bones
• Paired
bones form
the
posterior
part of the
hard palate
Zygomatic Bones
• The cheekbones
• Form the eye sockets
Lacrimal Bones
• Medial walls of the orbit (eye socket) with a groove for
tears (lacrima = tear)
Nasal Bones = #4
Vomer Bone
Inferior Nasal Conchae
Mandible
Hyoid Bone
• Not included with skull
• Closely related to the
mandible
• Does not articulate
(suspended)
• Base for tongue
movement
• Attachment for neck
muscles
• Not the Adam’s Apple,
that is the thyroid
cartilage surrounding the
larynx