Skeletal Flashcards
include the bones that form the longitudinal axis of the body or the trunk
Axial skeleton
bones of the limbs and girdles that attach them to the axial skeleton
Appendicular skeleton
•Support
•Protection
•Allow movement
•Storage
•Blood cell formation
Bones
dense and looks smooth and homogeneous
Compact bone
has a spiky, open appearance like a sponge
Spongy Bone
typically longer than they are wide
Long Bones
thin, flattened, and usually curved
Flat Bones
cube-shaped
Short Bones
Any bone that does not fit the aforementioned categorizes
Irregular Bones
have two thin layers of compact bone sandwiching a layer of spongy bone between them
Flat Bones
have shafts with enlarged ends
Long Bones
Generally composed of compact bone but also contain spongy bone at the ends
➢Ex: bones of the limbs
Long Bones
ex: most bones of skull, ribs, sternum
Flat Bones
contain mostly spongy bone with an outer layer of compact bone
➢Ex: sesamoid bone, wrist & ankle bones
Short Bones
mainly spongy bone with an outer layer of compact bone
➢ex: vertebrae
Irregular Bones
➢Shaft
➢makes up most of the bone’s length
➢composed of compact bone
Diaphysis
a fibrous connective tissue membrane that covers the diaphysis
Periosteum
Aka “Perforating Fibers”
Sharpey’S Fibers
secure the periosteum to the underlying bone
Sharpey’s Fibers
the ends of long bones
Epiphyses
consists of a thin layer of compact bone enclosing an area filled with spongy bone
Epiphyses
covers the external surface of the epiphysis
Articular Cartilage
composed of hyaline cartilage
Articular Cartilage
a distinct line found in adult bones
Epiphyseal Line
remnant of the epiphyseal plate
➢a flat plate of hyaline cartilage
➢seen in young, growing bones
➢cause the lengthwise growth of a
long bone
Epiphyseal Line
a delicate connective tissue that covers the inner bony surface of the shaft
Endosteum
cavity of the shaft
Medullary Cavity
in infants, it is a storage of red marrow
Medullary Cavity
➢produces blood cells
➢present until around the age of 6 or 7 then
it is gradually replaced by yellow marrow
➢in adults, can only be found in the cavities
of the spongy bone in the axial skeleton,
the hip bones, and the epiphyses of long
bones
Medullary Cavity
grow out from the bone surface
Projections or
Processes
indentations in the bone
Depressions or Cavities
small needle-like pieces of bone that comprises the spongy bone
Trabeculae
spaces filled by marrow, blood vessels, and nerves
Trabeculae
aka “osteon”
Haversian System
structural and functional unit of compact bone
Haversian System
mature bone cells
Osteocytes
aka “Haversian canal”
Central Canals
Haversian Systems:
• Osteocytes
• Lacunae
• Lamellae
• Central Canals
• Canaliculi
• Volkmann’S CanalS
Cells responsible for the formation of new bone tissue
Osteoblast
Cells responsible for the resorption of the
bone
Osteoclast
Derived from osteoblast
Osteocytes
Living element of the bone
Osteocytes
They regulate the flow of minerals into & out
the bone
Osteocytes
Primitive connective tissue will be replaced
by osteoid matrix
➢Ex: cranial bones, facial bones, & clavicle
Membranous phase
Aka “cartilaginous phase”
➢Ex: long bones, spine, ribs
Endochondral phase
Stages Of Bone Remodeling
- Osteoclast will be
activated
Activation
- Osteoclast will dissolve the bone
Resorption
- Osteoblast will be
recruited
Reversal
Formation of the new bone tissue
Formation
Bone will undergo dormancy until the next cycle begins
Quiescence
Stages Of Bone Remodeling:
• Activation
• Resorption
• Reversal
• Formation
• Quiescence
Aka “articulations”
Joints
sites where two or more bones meet
Joints
Two Functions
• hold the bones together securely
• give the rigid skeleton mobility
Joints
immovable joints
Synarthroses
no mobility to very slight mobility
Synarthroses
made up of fibrous structure
Synarthroses
slightly movable joints
Amphiarthroses
made up of cartilaginous structure
Amphiarthroses
mobility with stability
Amphiarthroses
➢freely movable joints
➢(+) synovial capsule
Diarthroses
bones are united by fibrous tissue
➢fxns:
• stability
• shock absorption
• force transmission
Fibrous Joints
come in two varieties, which differ in the type of cartilage involved:
Cartilaginous Joints
immovable joints linked by hyaline cartilage
SYNCHONDROSES
amphiarthrotic joints linked by discs of fibrocartilage
➢ ex: IV disc, pubis symphysis
SYMPHYSES
are joint in which the articulating bone
ends are separated by a joint cavity
containing synovial fluid
Synovial Joints
Synovial
Joint
• Articular cartilage
• Articular capsule
• Joint cavity
• Reinforcing ligaments
Flattened fibrous sacs lines with synovial membrane and containing a thin film of
synovial fluid
Bursae
They are common where ligaments, muscles, skin, tendons, or bones rub together
Bursae
an elongated bursa that wraps completely around a tendon subjected to friction
Tendon Sheath
➢articular surfaces are essentially flat
➢only short slipping or gliding
movements
➢movements are nonaxial
➢Ex: intercarpal joints
Plane Joint
cylindrical end of one bone fits into a
trough-shaped surface on another bone
Hinge Joint
Angular movements is allowed in just one plane
Hinge Joint
They are UNIAXIAL
➢Ex: elbow jt, ankle jt, knee jt
Hinge Joint
rounded end of one bone fits into a
sleeve or ring of bone uniaxial joints
➢Ex: PRU jt, AA jt
Pivot Joint
egg-shaped articular surface of one bone
fits into an oval concavity in another
Condylar Joint
allow the moving bone to travel (1) from
side to side and (2) back and forth, but the
bone cannot rotate around its long axis
Condylar Joint
➢biaxial
➢Movement occurs around two axes
➢Ex: MCP jts
Condylar Joint
➢each articular surface has both convex
and concave areas, like a saddle for a
horse
➢biaxial
➢Ex: CMC jt of the thumb
Saddle Joint
spherical head of one bone fits into the
round socket in another
Ball-And-Socket Joint
➢aka “universal jt”
➢multiaxial joints allow movements in all
axes, including rotation
➢most freely moving synovial joints
➢Ex: shoulder & hip joint
Ball-And-Socket Joint
