Download Axial skeleton and the Skull Lecture # 1 ppt

2 Divisions of
the Articulated
Skeleton:
-Axial skeleton(greenish)
-Appendicular
skeleton (beige)
Articulation -to form a joint
6 Types (categories) of bone form the skeleton:
Sutural bones
Long bones
(small bones
found in the
sutures of the
skull)
Flat bones
(the jelly sandwich)
(longer in
length than
in width)
Irregular bones
Short bones
(bones with odd/
complicated shapes
“cuboid”
Sesamoid bones
(bones
suspended in
tendons)
(more common
in Asians)
Flat Bones form a “jelly sandwich”
I. Surface Markings - structural features on bone adapted for
specific functions. Most develop after birth in response to
certain mechanical forces.
A.  Two Categories of surface markings: See Table 7.2, page 198.
a) Depressions & Openings – allows passage of soft tissue (nerves, etc).
b) Processes or Projections – joints, attachment pts. for muscle & tendon.
B. Functions of surface markings:
1) Attachment - of muscle, ligaments & tendons to bone.
2) Grooves - channels for nerves & blood vessels to pass.
3) “Bony Landmarks” - for surgeons to find organs.
Grooves in bone - provide
channels “protection” for
nerves & vessels to pass along
or through bone.
Fossa - a “shoveled-out” depression
fossa
Mandibular
fossa
Foramen - a “hole” through the
bone for which blood vessels, nerves
or ligaments pass. Many foramina.
Greater tubercle –
a small rounded
projection
Head - the ends of
long bones
Deltoid tuberosity –
a large rounded/roughened
projection
Head
Iliac crest - a prominent ridge
Linea asperaline is a less
prominent
ridge
Ischial Tuberosity Lateral condyle
A large rounded projection
Distal Femur
Anterior
Posterior
Condyle - a large
protuberence; a
“knuckle” at the end
of a bone.
Epicondyle - a
projection above (epi)
a condyle.
Temporal “tempo or time”
Styloid process
of temporal bone
Spinous process
A bony projection
on a vertebrae
Facet - a flat
articular surface
AXIAL SKELETON: The Skull
Skull- is made up of 22 bones; two divisions.
1)  Cranial (cranium) - 8 enclose & protects the brain.
2)  Facial bones - 14 bones.
Temporal
Mandibular Joint
or “TMJ”
Temporal - contains ear canal;
aka. external auditory meatus
Sphenoid - “keystone bone” forms the floor
of the cranium.
Ethmoid - lined with olfactory receptors
Mandible - lower jaw; evolved from
gill arches in fish.
Snakes can dislocate their jaw when feeding
Inferior View
Zygomatic arch “cheek
bone”
Occipital
Articulates
with the
vertebral
column.
Cleft palate - failure of palatine & maxilla to fuse during
development
Inferior View
Zygomatic arch “cheek
bone”
Occipital
Articulates
with the
vertebral
column.
Bones that make up the roof of the mouth
Upper Cleft lip
Cleft palate – before and after reconstruction