Download Chapter 6: Osseous Tissue and Bone Structure

Structures of Bones
• Articulations:
– contacts with other bones
• Marks:
– areas of muscle and ligament attachment
• Foraminae:
– openings for nerves and blood vessels
Bone Markings
Table 6–1 (1 of 2)
Bone Markings
Table 6–1 (2 of 2)
Discussion
Why are bone markings important?
The Axial Skeleton
PLAY
3D Peel-Away of Whole Axial Skeleton
Figure 7–1a
The Axial Skeleton *
• The axial skeleton:
– forms the longitudinal
axis of the body
– has 80 bones
• The skull:
– 8 cranial bones
– 14 facial bones
• Bones associated with
the skull:
– 6 auditory ossicles
– the hyoid bone
Figure 7–1b
Bones of the Axial Skeleton
• The vertebral
column:
– 24 vertebrae
– the sacrum
– the coccyx
Bones of the Axial Skeleton
• The thoracic cage:
– 24 ribs
– the sternum
Functions of the Axial Skeleton
• Supports and protects organs in body
cavities
• Attaches to muscles of:
– head, neck, and trunk
– respiration
– appendicular skeleton
Discussion
• What are the sections of the axial
skeleton?
• What are the functions of the axial
skeleton?
The Skull
• The skull protects:
– the brain
– entrances to respiratory system
– entrance to digestive system
• Has 22 bones:
The Skull
– 8 cranial bones:
• form the braincase or cranium
– 14 facial bones:
• protect and support entrances to digestive and respiratory tracts
Figure 7–2
Cranial Bones
• Enclose the cranial cavity
• Which contains the brain:
– and its fluids, blood vessels, nerves, and
membranes
The Facial Bones
• Superficial facial bones:
– for muscle attachment
• Deep facial bones:
– separate the oral and nasal cavities
– form the nasal septum
Sinuses
• Cavities which decrease the weight of
the skull:
– lined with mucus membranes
– protect the entrances of the respiratory
system
Sutures
• (A seam-like immoveable joint between two
bones)
• The immovable joints of the skull
Figure 7–3a, b
1.
2.
3.
4.
Lambdoid suture
Coronal suture
Sagittal suture
Squamous suture
Figure 7–3c
Sutures
Lambdoid:
• Separates occipital from parietal bones
• May contain sutural bones
Frontal bone
Coronal:
• Attaches frontal bone
to parietal bones
• The calvaria:
– consists of occipital,
parietal, and frontal
bones
Parietal bone
Occipital bone
Sutures
Sagittal suture:
• Between the parietal bones
• From lambdoid suture to coronal suture
Squamous suture:
* Form the boundaries between temporal bones
and parietal bones
What are the bones of the
cranium, and the significance
of their markings?
The Cranial Bones
•
•
•
•
•
•
Occipital bone
Frontal bone
Sphenoid
Ethmoid
Parietal bones
Temporal bones
The Occipital Bone
Figure 7–5a
The Parietal Bones
Figure 7–5b
The Frontal Bone
Figure 7–6
The Temporal Bones
Figure 7–7
The Sphenoid
Figure 7–8
The Ethmoid
Figure 7–9
What are the differences
between the skulls of infants,
children, and adults?
The Infant Skull
• Grows rapidly; is large compared to the body
• Has many ossification centers
• Fusion is not complete at birth:
– 2 frontal bones
– 4 occipital bones
– several sphenoid and temporal elements
Figure 7–15
Fontanels
• Are areas of fibrous connective tissue (soft
spots)
• Cover unfused sutures in the infant skull
• Allow the skull to flex during birth
The 4 Fontanels
• Anterior fontanel:
– frontal, sagittal, and coronal sutures
• Occipital fontanel:
– lambdoid and sagittal sutures
• Sphenoidal fontanels:
– squamous and coronal sutures
• Mastoid fontanel:
– squamous and lambdoid sutures