Chapter 6 Bone Physiology Flashcards
Primary functions of the skeletal system
Support
Storage of minerals and lipids
blood cell production
protection
leverage
What is included in the skeletal system?
Bones of the skeleton
Cartilages, ligaments, and other connective tissues that stabilize and connect.
What do bones store?
Inorganic ions, calcium ions, phosphorus ions, lipids in yellow marrow
Axial skeleton
Bones that make up the central axis of the body
Appendicular skeleton
Bones that make up the appendages of the body
types of bones
longs
short
flat
irregular
sesamoid
compact bone
closer to solid
closer to the surface to provide stability
Spongy bone
an open network
interior of bone
long bone includes
diaphysis
epiphyses
metaphysis
articular cartilage
marrow cavity
diaphysis
tubular shaft
contains marrow cavity
Metaphysis
connects diaphysis to epiphysis
Epiphysis
end of bone
mainly spongy bone
form complex joints and synovial fluid
bone marrow
in marrow cavity within diaphysis
contains yellow marrow which stores fat
coontains red marrow which produces blood cells
diploe
sandwich of spongy bone
contains bone marrow within spongy network
Osseous tissue is what?
Supporting connective tissue
4 characteristics of bone
dense matrix- contains calcium salts
osteocytes- bone cells housed within lacunae
canaliculi forms network between lacunae
periosteum
How much of the bone matrix is calcium phosphate?
2/3
crystalline hydroxyapatite formula?
calcium phosphate + calcium hydroxide
crystalline hydroxapatite bind to make what?
calcium carbonate, sodium ions, magnesium ions, and fluoride ions
what does calcium phosphate provide?
resistance to compression and rigidity
what do collagen fibers provide?
resistance to tension and binding material for calcium crystals
what do protein-crystal interactions provide?
strength, flexibility, and shatter resistance to bone
cells in bone
osteocytes
osteoblasts
osteoprogenitor cells (stem)
osteoclasts
mature bone cells
osteocytes
occupies the lacuna within lamella layers
osteocytes
cannot divide; lacuna contains only one
osteocytes
canaliculi connects lacunae through what?
lamellae
2 major functions of osteocytes
maintain protein and mineral content of the matrix
help repair damaged bone by becoming osteoblast or osteoprogenitor cell if needed
produce new bone matrix through osteogenesis
osteoblasts
make and release proteins and other matrix components
osteoblasts
organic matrix is called what before calcium salt deposition?
osteoid
helps to elevate calcium phosphate levels locally
osteoblasts
promote calcium salt deposition
osteoblasts
osteoblasts become osteocytes when?
when surrounded by matrix
type of mesenchymal cell
osteoprogenitor cells
stem cell that divides into daughter cells to produce osteoblasts
osteoprogenitor cells
maintain osteoblast populations
osteoprogenitor cells
help repair fractures
osteoprogenitor cells
osteoprogenitor cells located in?
cellular layer of periosteum
endosteum
vascular passages of matrix
remove bone matrix
osteoclasts
giant cells; multinucleate
osteoclasts
related to macrophages; both monocytes
osteoclasts
secretes acid and protein destroying enzymes to break down matrix and release minerals
osteoclasts
process called osteolysis important in regulation of what?
calcium and phosphate ion concentration
bone composition depends on what?
osteoblasts to osteoclasts relationship
functional unit of compact bone
osteon
osteocytes are arranged how in compact bone?
concentric layers around central canal
what does the central canal contain?
blood vessels that carry blood to and from the osteon
perforating canals do what?
run perpendicular to the central canals; blood vessels contained in here supply deep bone tissue and marrow cavity
concentric lamellae from what
nested cylinders around central canal
inertsitial lamellae do what?
fill spaces between osteons due to breakdown by osteoclasts
circumferential lamellae
found around in the outer surfaces and covered by periosteum and in the inner surfaces covered by endosteum
where is compact bone the thickest?
where stresses arrive from limited range of directions
osteons aligned the same…
strong when stressed along the axis of alignment
lamellae arrangement in spongy bone
lamellae is not arranged in osteons
what is the name of the network formed by the matrix in spongy bone?
trabeculae
are there blood vessels in the matrix of spongy bone?
no
what canals does diffusion take place in spongy bone
canaliculi open the surfaces of trabeculae and diffusion takes place within these canals
where is spongy bone located
areas of less stress
trabeculae are along stress lines with what?
with extensive cross-branching
spongy bone transfers forces where?
adjacent compact bone
what does spongy bone do to the weight of the skeleton?
it reduces it
what does spongy bone protect?
bone marrow cells
located where stresses are limited in direction
compact bone
located where stresses are weaker or multi-directional
spongy bone
superficial layer of bone
periosteum
functions of the periosteum
isolates bone from surrounding tissue system interactions
helps with bone growth and repair
periosteum is
continuous with surroundings
interwoven with tendons attached to bone- very strong attachment
the incomplete cellular layer that lines the marrow cavity
endosteum
Endosteum functions
active during bone growth, repair, and remodeling
covers trabeculae and lines central canals
consists of osteoprogenitor cells
where cellular layer is not complete osteoblasts and osteoclasts are active
what is calcification
depositing calcium salts within tissues
what is ossification
converting other tissue to bone
bone production between membranes
intramembraneous ossification
what type of ossification produces flat bones
intramembraneous
cartilage model becomes long bone
endochondral ossification
where does the bone get longer
metaphysis
Nutrient artery and veins
supply diaphysis form during beginning of endochondral ossification
enter through nutrient foramina
branches of vessel form perforation canal
Metaphyseal vessels
supply blood to inner surface of epiphyseal cartilage
where osteoblasts are active
periosteal vessels
blood vessels from the periosteum
supply the superficial osteons
also supply secondary ossification areas in epiphyses
after closure of epiphyses
all types are interconnected
step one of bone remodeling
minerals removed from bone matrix and released into circulating blood
step two of bone remodeling
simultaneously circulating minerals are absorbed and deposited
step tree of bone remodeling
involves interaction between osteocytes, osteoblasts, and osteoclasts
step four of bone remodeling
osteoblasts forming osteons and osteoclasts are breaking down osteons
what is the bone turnover rate
1/5 is replaced in a year - high turnover rate
what can take the place of calcium
heavy minerals - these materials can stay in bone for long periods
what can happen as heavy minerals are released over the remodeling process?
it can lead to great complications and disease over time (leukemia and cancer)
what are attracted to electrical stimuli
osteoblasts
why bone remodeling
helps bones adapt to many situations that the body is exposed to
what does stress do to bones
it makes them thicker
nutrients for bone growth
vitamin C vitamin K and vitamin b12
hormones for bone growth
calcitrol, growth hormone, thyroxine, sex hormones
what does growth hormone do
stimulates protein and cell growth
what does thyroxine do?
helps maintain metabolism in cells
what do hormones do for bone growth
maintain epiphyseal cartilage (plate) until puberty
what causes osteoblasts to work faster than cartilage expansion?
sex hormones
what causes epiphyseal cartilage to close and growth to stop
sex hormones
pott’s fracture
in the ankle and affects both bones of the leg
comminuted fractures
shatter the affected area into multitude of bony fragments
transverse fracture
break a shaft bone across its long axis
spiral fracture
produced by twisting stresses that spread along the length of the bone
displaced fracture
new and abnormal bone arrangemnets
non-displaced fractures
retain the normal alignment of the bones or fragments
colles’ fracture
break in the distal portion of the radius, typically the result of trying to cushion a fall
epiphyseal fracture
tend to occur where the bone matrix is undergoing calcification and chondrocytes are dying
greenstick fracture
one side of the shaft is broken and the other is bent - usually in children
compression fracture
in vertebrae subjected to extreme stresses
what is joint classification based on
structure or anatomy
function or “range of motion”
synarthrosis
immovable joint
amphiarthrosis
slightly movable joint
diarthrosis
freely movable joint
symphysis
articulation separated by pad or wedge of fibrocartilage
gomphoses
bolting together of teeth to maxilla and mandible
synovial membrane lines the walls of the articular capsule
diarthroses
suture joint
between flat bones of the skull - stitched together
anatomical classifications
bony
fibrous
cartilaginous
synovial
flexion
reduction in angle of articulating elements (anterior-posterior plane)
surrounded by articular capsule
diarthroses
created by the continuation of periosteum of the two articulating bones
articular capsule
extenison
increase in the angle of articulating elements (anterior-posterior plane)
linear motion
gliding motion
abduction
away from longitudinal axis of the body
adduction
toward the longitudinal axis of the body
pronation
roataion involving the wrist and forearm; palm facing front to palm facing back
lateral rotation
opposite of medial rotation
medial rotation
anterior movement toward the long axis or midline
circumduction
the motion of “drawing a circle”
supination
roation involving the wrist and forearm; palm tuned anteruorly
left rotation/right rotation
rotation described versus Medline or longitudinal axis
inversion
twisting motion of foot turning sole inward
eversion
opposite of inversion
dorsiflexion
flexion at ankle and elevation of the sole
planter flextion
opposite of dorsiflexion
opposition
movement of thumb toward the palm or fingers
protraction
movement of a body part anteriorly in the horizontal plane
retraction
opposite of protraction
elevation
movemnet of a body part superiorly
depression
movement of a body part inferiorly
lateral flexion
vertebral column bending to side
