Unit 4 Skeletal System
1. List the 5 functions of the
Skeletal System
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Supports the body
Protects soft body parts
Produces Blood Cells
Stores fats and minerals
Permit body Movement
2. Label a long bone
• Compact (dense)
• Makes up the
DIAPHYSIS
• Hollow center is
called MEDULLARY
cavity and is where
yellow bone marrow
is
2. Diagram of a long bone
• Spongy ( cancellous)
• Also called
TRABECULAE
• Makes up the
EPIPHYSIS
• Lighter, design for
strength
• Contains red blood
marrow
Dental Compact and Spongy
• What teeth
are these?
2.What is the relationship of the
Epiphyseal disk to Growth?
• The epiphysis of a
bone is covered with
a disk made of
cartilage
• As the bone grows
larger, the disk
recedes
• When the bone has
grown as large as it
will get- the disk is
GONE
Epiphyseal disk and Growth
• An orthodontist may xray the wrist of a
patient to see the size of the disk to
determine if the patient is done growing.
• A patient with crowded teeth may not need
braces if there is going to be growth of the
jaw bones to accommodate the teeth!
3. 2 Types of Bone
development
• Bone formation is called ossification
• Long bones develop from
cartilage=ENDOCHONDRIAL
• All other bones develop from connective
tissue= INTRAMEMBRANOUS
• Osteoblast- cell that produces bone
• Osteoclasts- resorb bone
4. Skeleton is divided into the Axial
and Appendicular
AXIAL
• Skull (face & cranium)
• Vertebra
• Thoracic
APPENDICULAR
• Pectoral
• Upper Limbs(arms)
• Pelvic
• Lower limbs( legs)
4. 14 Facial Bones of the SKULL
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2 Maxillae
2 Palatal
2 Zygomatic
2 Lacrimal
2 Nasal
2 Inferior Nasal
Conchae
• 1 vomer
• 1 Mandible
More on the Facial bones
• Maxillae- upper jaw
• Zygomatic- cheek
• Lacrimal- tear duct in
corner of eye
• Nasal- bridge of nose
where glasses sit
• Inferior conchae- spiral
shaped inside nostrils
• Vomer- divides nostrils
• Mandible- lower jaw
Facial bone- Palatal
• Palatal- small L
shaped bone behind
the palatal process of
the maxillae
8 Cranial Bones of the Skull protect
the brain
• 1 Frontal- forehead
• 2 Parietal- top of head
• 1 Occipital- base, where
vertebae attach
• 2 Temporal- temples
• 1 Sphenoid- outside eye
orbits
• 1 Ethmoid- inside eye
orbits
Hyoid Bone
hyoid
• The hyoid bone is a
horseshoe shaped bone
in the neck. It is the
ONLY bone in the body
that does not articulate
with another bone! It
anchors the tongue so
that you can not swallow
it and serves as an
attachment site for
muscles that make up the
floor of the mouth.
The 5 Regions of the Vertebral
Column
• Cervical- 7- neck area
• Thoracic- 12- chest area
• Lumbar- 5- small of back
• Sacrum- 5- hip area
• Coccyx- fused- tailbone
Vertebra=spine
Bones seperated by disks
Bones of the THORACIC Cage
(CHEST)
• 12 pair of RIBS
• STERNUM
The tip of the
sternum is called the
XYPHOID processyou will hear of this in
CPR
Thoracic bones protect
the heart and lungs!
Name the 4 sections of the
APPENDICULAR skeleton
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PECTORAL- shoulder
UPPER LIMB- arms
PELVIC- hip
LOWER LIMB- legs
Next, let’s look at the major bones in each of
these sections of the appendicular
skeleton
PECTORAL(shoulder)
• CLAVICALcollarbone
• SCAPULA- shoulder
blade
UPPER LIMB
• HUMEROUS- upper arm
(funny bone)
• RADIUS- lower arm bone
by on side by thumb
• ULNA- lower arm bone
by little finger
• HAND
carpal-wrist
metacarpal-hand
phalanges- fingers
PELVIC- hip
• 2 COXAL bones
• Connected in the
middle by the
SACRUM
LOWER LIMB- leg
• FEMUR- upper leg bone
• TIBIA- lower leg, shin,
more anterior
• FIBULA- lower leg,
thinner, more posterior
• FOOT
TARSALS- ankle
METATARSALS- foot
PHALANGES- toes
5. Name the 3 types of joints
(ARTICULATIONS)
• Synarthrotic- no movement- skull sutures
• Amphiarthrotic- slight movement- ribs and
vertebrae
• Diarthrotic/ Synovial- freely movingmandible, knee, shoulder, hip, fingers
The end