Download Axial skeleton

Bones!
• 2 categories
– Axial Skeleton
– Appendicular Skeleton
• Function:
– Support, protection, body movement,
hematopoeisis, fat storage, mineral storage
Axial Skeleton
• Skull,
vertebral
column,
and thorax
Classification of bones
• Long Bones:
– Longer than they are wide
• Ex: humerus, radius
• Short Bones:
– Bones that are somewhat cube-shaped
• Ex: Tarsals (ankle bones), carpals (wrist bones)
• Flat Bones:
– Thin with 2 layers of compact bones sandwiching spongy bone
• Ex: Cranial bones (skull), ribs, scapula
• Irregular Bones: Varied shape
• Ex: vertebrae
• Wormian Bones (sutural bones):
– Bones within the sutures (joints) of the skull
• Sesamoid Bones:
– Bones that develop in tendons
• Ex: Patellae (knee caps)
Bone Markings
• Reveal where the bones form joints; where
muscles, tendons, and ligaments attach;
where blood vessels and nerves are passed
• 2 groups:
– 1 ) projections/ processes
– 2) Depressions/ cavities
Processes/ Projections
• Process – extension of a bone away from the bone’s surface.
• Line - narrow ridge or border. Example: linea aspera of femur.
• Condyle – rounded eminence that articulates with a depression or a
fossa on another bone.
• Epicondyle – raised, rounded area located above a condyle.
• Trochanter – very large, roughened, raised area found on the
femur.
• Tuberosity – similar to a trochanter but smaller.
• Crest – narrow ridge of bone.
• Tubercle – small rough process for muscle or tendon attachment
• Spine – sharp, slender projection
• Head – rounded, enlarged end of a long bone, Sits atop a narrow
portion of the bone called the neck.
• Ramus - arm-like bar of bone
Depressions/ Cavities
• Fossa – shallow depression that usually articulates with a
condyle or head of another bone. Sometimes referred to as
cavities.
• Foramen (pl. foramina) – hole for passage of nerves, blood
vessels, or the spinal cord.
• Meatus – canal-like passageway.
• Facet - Smooth flat articular surface. Ex: Superior Articular
facet of vertebra. Forms parts of joints.
• Line - narrow ridge or border. Example: linea aspera of
femur.
• Sinus - hollow cavity within bone
• Fissure – deep grooves or slit-like opening
f Cranial Bones
Facial Bones g
Anterior Aspects of the Skull
Inferior Portion of the Skull
Fig. 8.10a
• Form most of the superior
and lateral aspects of the
skull
Figure 7.3a
Inferior Portion of the Skull
Figure 7.4b
Sphenoid Bone
Figure 7.6a, b
Hyoid
Skull: Posterior View
(Wormian Bone)
Figure 7.2b
Parietal Bones and Major Associated Sutures