what are bones made up of
- osseous tissue
- dense regular and irregular collagenous connective tissue as well as bone marrow- red (homocoeic tissue) and yellow (fat storage)
what are the 6 functions of the skeletal system?
- protection
- mineral storage and acid-base homeostasis
- blood cell formation
- fat storage
- movement
- support
this bone structure is longer than it is wide; ex: humerous
long bone
this bone structure is as long as it is wide; ex: wrist and ankle bones
short bone
this bone structure is thin and broad bones; ex: pelvis, sternum
flat bones
this bone structure is doesn’t fit in the other classes; ex: vertebrae and skull
irregular bones
this bone structure is flat, round; w/in tendon; ex: patella/ knee cap
sesamoid bones
in a long bone and forms a covering, rich with blood vessels and nerves; surrounds outer surface of long bones
periosterum
anchors periosteum firmly to underlying bone surface by penetrating deep into bone matrix
perforating fibers (slide 17)
shaft of the long bone
diaphysis
end of long bone
epiphysis
marrow cavity contains what?
either red or yellow bone marrow, depending on bone and age of individua
hard, dense outer region that allows bone to resist linear compression and twisting forces among other stresses outside
compact bone
honeycomb-like framework of bony struts; allows long bones to resist forces from many directions; provides a cavity for bone marrow middle of bone
spongy bone
Bony struts of spongy bone and all inner surfaces of bone are covered by a thin membrane
called endosteum
found separating both proximal and distal epiphyses from diaphysis
epiphseal lines
Blood supply to short, flat, irregular, and sesamoid bones is provided mostly by vessels in where?
periosteum
Long bones get a third of their blood supply from where?; mostly supplies compact bone
periosteum
Remaining two-thirds (in long bone) is supplied by what?;
one or two nutrient arteries
what is found in the ends of long bone in epandageous; in femur, sternum, hip, and humerous; replaced by yellow marrow
red blood marrow
who has more red blood marrow a child or an adult?
Children need more red marrow to assist in their growth and development
; amount of red blood marrow decreases w age
what is composed of triglycerides, blood vessels, and adipocytes
yellow blood marrow
substance in inorganic matrix
hydroxypatetie
predominant protein fiber; forms cross-links with one another; helps bone resist torsion (twisting) and tensile (pulling or stretching) forces
collagen
describe how osteoblasts turn into osteocytes
- osteogenic cells differenciate into osteoblasts
- osteoblasts deposit bone until they are trapped until they become osteocytes
- Osteocytes maintain bone ECM
Each osteon contains between 4 and 20 lamellae arranged in layered ring structures also known as this; rings of hard, calcified, intercellular substance
concentric lamallae (another way to say lamallae)
in the osteon structure a endosteum-lined hole found in center of each osteon where blood vessels and nervesreside to supply bone
central canal (haversian canal)
Osteocytes reside in where?
lacunae
small cavities found between lamellae; filled with extracellular fluid
in the osteon structure a Neighboring lacunae are connected to one another by a network of small passageways or canals in matrix called what?
canaliculi
Are remnants of concentric or circumferential lamellae that were partially removed during bone remodeling or after osteoclasts.
interstitial lamallae
Lamellae wrapped around the long bone; Bind osteons together; part of appositional growth
circumferential lamallae
originate from blood vessels in periosteum and travel at right angles (perpendicular) to central canals of osteons; through which the blood vessels and
nerves from the periosteum penetrate the compact bone.
perforating canals (valkmans canals)
usually not weight-bearing like compact bone so is much less densely packed; Provide a protective structure for bone marrow tissue
spongy bone
This begins in embryonic period and continues through childhood with most bones completing the process by age 7; Process of bone formation is called what
ossification or osteogenesis;
Bones formed by what are built on a model (starting material) made of a membrane of embryonic connective tissue
intramembranous ossification
Bones formed by what are built on a model of hyaline cartilage; most common
endochondral ossification
dermal layers thicken can produce select bones; found in bones on face;
Dermal intramembranous formation-
when bones grow in width its called
appositional growth
concentric rings of bone matrix. This gives compact bone a great deal of strength like a tree’s rings.
lamallae
multinuclei; special enzymes and acids w/in them; break fown osteon itself to provide necessary ions to keep body functioning
osteoclasts
Long bones lengthen by a process called
longitudinal growth