Download Frontal bone - PA

Skeletal System
Frame work of the body
Bones
Cartilages
Joints
The bones, muscles & joint form an
integrated system- Musculoskeletal system
Orthopedics is prevention & correction of
disorders of the musculoskeletal system
Human Skeleton
206 bones
Skeletal System
Divisions
• Axial skeleton (80): Skull, Hyoid bone,
Ribs, Sternum etc.
• Appendicular skeleton (126): Upper &
lower extrimities & Limb girdles
Axial Skeleton
Types of
bones
Classification
• Long bones
• Short bones
• Flat bones
• Irregular bones
• Sesamoid bones
• Sutural bones
Cranial Bones
• Frontal bone - This large bone forms the forehead region, roof of the orbit
and anterior part of the cranial cavity
• 2. Parietal bones - These two large bones form the greater part of the
superior and lateral part of the skull. They join together at a suture on the
midline and also join with the frontal bones. The word "parietal" means
wall and these bones form much of the lateral "walls" of the skull.
• 3. Temporal bones - These bones make up the "temple" region of the skull
superior and anterior to the ear hole. There is a large region of contact
between the superior edge of the temporal bone and the inferior part of the
parietal bone.
• 4. Occipital bone - This large bone forms the posterior and inferior base of
the cranium. It is through this bone that the skull is supported by the
vertebral column. The large hole in the base of the skull (foramen magnum)
pierces the occipital bone.
• 5. Sphenoid Bone – Lies at the middle part of the base of the skull. A key
stone of the cranial floor because it articulates with all the other cranial
bones.
Bones of the Face
• 1. Nasal bones - These bones form the skeleton of the bridge
of the nose. The major structure portion of the nose consists of
flexible cartilage.
• 2. Zygomatic bones - These bones, in common language, are
the cheek bones. They lie inferior and lateral to the eye
sockets.
• 3. Maxillary bones (Maxilla) - These bones are the upper jaw
bone and holds the upper teeth. They extend far up toward the
medial part of the eye socket.
• 4. Mandible bone - This large bone is the lower jaw bone
which holds the lower teeth. Note that the joint-bearing part of
the bone extends up to near the ear region of the skull.
Facial Bones (14 bones)
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2 nasal bones
2 maxillae
2 Zygotic bones
The mandible
2 lacrimal bones
2 palatine bones
2 inferior nasal conchae
Vomer bone
Hyoid Bone
Vertebral Column
Term
# of Vertebrae
Body Area
Abbreviation
Cervical
7
Neck
C1 – C7
Thoracic
12
Chest
T1 – T12
Lumbar
5
Low Back
L1 – L5
Sacrum
5 (fused)
Pelvis
S1 – S5
Coccyx
3
Tailbone
None
Functions of the Vertebral or Spinal Column
Protection
Spinal Cord and Nerve Roots
Many internal organs
Base for Attachment
Ligaments
Tendons
Muscles
Structural Support
Head, shoulders, chest
Connects upper and lower body
Balance and weight distribution
Flexibility and Mobility
Flexion (forward bending)
Extension (backward bending)
Side bending (left and right)
Rotation (left and right)
Combination of above
Other
Bones produce red blood cells
Mineral storage
Bones of the Thoracic Cage
• The thoracic cage consists of 12 pairs of ribs, the
costal cartilages and the sternum (commonly called
the breastbone).
• 1. The ribs are long, thin C-shaped bones. The lower
two pairs are straighter and shorter. Posteriorly they
attach to the thoracic vertebrae and anteriorly (except
for the lower two pairs) they attach to the sternum.
• 2. The sternum is a flat bone, shaped somewhat like
a stone arrowhead. It is the most anterior and medial
part of the thoracic cage.
• 3. The costal cartilages are the flexible structures by
which the ribs are attached to the sternum.
Thoracic cage