Lab 2: Osteology: The Axial Skeleton Flashcards
how many bones do we have at birth
about 300
how many bones do we have in adulthood
206-213
what are the two major divisions of the skeleton
- axial skeleton
- appendicular skeleton
how many bones are in the axial skeleton
80
how many bones are in the appendicular skeleton
126
what are the 5 major functions of the skeletal system
- support
- movement
- protection
- storage of minerals
- production of blood cells
what are the major bones of the cranium
- frontal
- parietal
- temporal
- occipital
- sphenoid
- ethmoid
- maxilla
- mandible
what are the two different types of bones that differ based on texture
- compact bone
- spongy bone
describe compact bone
look smooth and homogenous
describe spongy bone
composed of small trabeculae (tiny beams and struts) of bone and lots of open spaces
what are the four classifications of bones based on gross anatomy
- long bones
- short bones
- flat bones
- irregular bones
describe long bones
- longer than they are wide
- generally consist of a shaft with heads at either end
- primarily composed of compact bone
describe short bones
- roughly cube-shaped
- contain more spongy bone than compact bone
describe flat bones
- flattened along a major aspect of their geometry, can be curved
- two wafer-like layers of compact bone between a layer of spongy bone
describe irregular bones
do not fit into other categories due to irregular morphology
define periosteum
- encapsulates bones
- tough and fibrous membrane
- appears shiny and glossy
describe the two layers of the periosteum
- outer fibrous layer where muscle tendons and bone ligaments attach
- inner cellular layer that produces osteoblasts for bone growth and repair
define diaphysis
long central shaft of long bones
define epiphysis
ends of long bones
define proximal epiphysis
end of the long bone closest to the trunk of the body
define distal epiphysis
end of the long bone furthest away from the trunk of the body
define articular cartilage
- layer of hyaline cartilage
- covers epiphysis where it articulates with another bone
what is the wall of the diaphysis made of
compact bone
define marrow (medullary) cavity
- hollow interior of diaphysis
- contains yellow marrow with high concentration of lipids
define endosteum
membrane lining the marrow/medullary cavity
define metaphysis
area between the diaphysis and epiphysis
define epiphyseal line
- separates epiphysis from diaphysis
- replaces epiphyseal plate during the transition from the juvenile stage to adulthood
when does bone growth stop
when the cartilage of the epiphyseal plate disappears and is replaced by the bone epiphyseal line
do flat bones have a marrow/medullary cavity
no
describe the naming of the bone layers of flat bones
- cortex: compact bone layers collectively
- internal and external tables: compact bone layers individually
- diploe: spongy bone between the tables
where is red marrow found in flat bones
spongy bone in the middle called the diploe
define bone markings
reveal where bones form joints with other bones; where muscles, tendons and ligaments were attached; where blood vessels and nerves pass
what are the two major categories of bone marking
- projections
- depressions
define projections
- processes that grow out from the bone
- serve as sites of muscle attachment or to help form joints
define depressions
- indentations or openings in the bone
- serve as conduits for nerves and blood vessels
describe this bone marking: tuberosity
- projection
- large rounded projection
describe this bone marking: crest
- projection
- narrow ridge of a bone, usually prominent
describe this bone marking: trochanter
- projection
- very large, blunt, irregularly shaped process
describe this bone marking: line
- projection
- narrow ridge of a bone, less prominent than a crest
describe this bone marking: tubercule
- projection
- small rounded projection or process
describe this bone marking: epicondyle
- projection
- raised area on or above a condyle
describe this bone marking: spine
- projection
- sharp, slender, often pointed projection
describe this bone marking: process
- projection
- any bony prominence
describe this bone marking: head
- surface that forms joint
- body expansion carried on a narrow neck
describe this bone marking: facet
- surface that forms joint
- smooth, nearly flat articular surface
describe this bone marking: condyle
- surface that forms joint
- rounded articular projection, often articulates with a corresponding fossa
describe this bone marking: ramus
- surface that forms joint
- arm-like bar of bone
describe this bone marking: foramen
- depression
- round or oval opening through a bone
describe this bone marking: groove
- depression
- furrow
describe this bone marking: fissure
- depression
- narrow, slit-like opening
describe this bone marking: notch
- depression
- indentation at the edge of a structure
describe this bone marking: fossa
- depression
- shallow basin-like depression in a bone, often serving as an articular surface