SKELETAL SYSTEM Flashcards
∙ Support of the body
∙ Protection of soft organs
∙ Movement due to attached skeletal
muscles
∙ Storage of minerals and fats
∙ Blood cell formation
Bones
Parts of the skeletal system
∙Bones (skeleton)
∙ Joints
∙ Cartilages
∙ Ligaments (bone to bone)(tendon=bone to
muscle)
two divisions of the skeletal system
∙Axial skeleton
∙Appendicular skeleton – limbs and girdle
No. Of skeletal bones
206
Two basic types of bone tissue
∙Compact bone
∙ Homogeneous
Small needle-like
pieces of bone
∙ Many open spaces
Spongy bone
Classification of Bones
. Long bones
∙ Short bones
∙ Flat bones
∙ Irregular bones
∙Typically longer
than wide
∙Have a shaft with
heads at both ends
∙Contain mostly
compact bone
•Examples:
Femur, humerus
Long bones
∙Generally cube-shape
∙Contain mostly
spongy bone
∙Examples: Carpals,
tarsals, sesamoids
Short bones
∙Thin and flattened
∙Usually curved
∙Thin layers of compact
bone around a layer of
spongy bone
∙Examples: Skull, ribs,
sternum
Flat bones
∙Irregular shape
∙Do not fit into other
bone classification
categories
∙Example: Vertebrae
and hip
Irregular bone
the process of bone formation
by osteoblasts
Ossification
the process of bone development from fibrous
membranes.
∙ It is involved in the formation of the flat bones of the
skull, the mandible, and the clavicles.
∙ Occurs in a 12-week old fetus at ossification centers
Intramembronous Ossification
process of bone development from hyaline
cartilage.
∙ Occurs in all bones except flat bones
Endochondral Oassification
allow for growth of
long bone during childhood
Epiphyseal plate
shaft; composed of
compact bone
Diaphysis
ends of the bone;
composed of mostly spongy bone
Epiphysis
covers the
external surfaces of the epiphyses
Articular cartilage
Growth plate
Epiphyseal plate
cavity of the shaft;
contains the red and yellow marrow
Medullary cavity
Outer covering of the
diaphysis
Periosteum
Inner covering of the
diaphysis
Endosteum
A unit of bone
Osteon
Carries blood vessels and
nerves
Central canal
Cavities containing bone
cells (osteocytes)
Lacunae
Rings around the central
canal
Lamellae
Tiny canals
• Forms a transport system
Canaliculi
A break in a bone
Bone fractures
Types of bone fractures
Closed (simple) fracture – break that does not
penetrate the skin
∙Open (compound) fracture – broken bone
penetrates through the skin
the place where
two bones come together
Joints
Three types of joints classified by the
amount of movement:
Synarthrosis – Immovable
• Amphiarthrosis – Slightly movable
• Diarthrosis – Freely movable
Three types of joints classified by its
structure:
. Fibrous
• Cartilaginous
• Synovial
Forms the longitudinal part of the body
∙ Divided into three parts
∙Skull
∙Vertebral column
∙Bony thorax
The axial skeleton
Two sets of bones
Cranium 8 and facial bones 14
The only bone that
does not articulate
with another bone
∙ Serves as a
moveable base for
the tongue
Hyoid bone
Vertebrae
separated by
intervertebral discs
∙ The spine has a
normal curvature
∙ Each vertebrae is
given a name
according to its
location
The vertebral column
Forms a
cage to
protect
major
organs
The body thorax
Bony thorax is Made-up of
three parts
∙Sternum
∙Ribs
∙Thoracic
vertebrae
A slight elevation at the
junction of manubrium and
body of the sternum
• At the level of T4
Sternal angle
• A depression located between
the ends of the clavicles
• At the level of T3
Jugular notch
These bones allow the upper limb to
have exceptionally free movement
The pectoral girdle
Region between the shoulder and the elbow
Humerus
The forearm
has two bones
Ulna and radius
