Exam 2 Flashcards
Chapters 6
4 components of the skeletal system
bones, cartilage, tendons and ligaments
6 functions of the skeletal system
- framework for body (support/ bear weight)
- protection (organs)
- allow movement
- store minerals in bone (Ca, P)
- stores adipose in bone cavity (yellow marrow)
- red bone marrow (hematopoiesis)
what attaches muscles to bone
tendons
what holds bones together
ligaments
what cartilage is in the embryonic skeletal and bone
hyaline
3 cartilage types in the skeletal system
hyaline, elastic, and fibrocartilage
what cartilage is at the ends of bones that help with glide and friction
hyaline
what cartilage has a glassy background and collagen
hyaline
what cartilage is elastin, flexible: external ear and epiglottis
elastic
what cartilage has collagen fibers, strong and often found in pubic symysis, knee mensicus and intervertebral discs
fibrocartilage
2 types of cartilage growth
appositional and interstitial
cartilage forming cells secrete new matrix against external face of existing caritlage
appositional
chrondrocytes divide and secrete new matrix, expand cartilage from within
interstitial
reinforced concrete is
bone matrix
components of bone matrix
collagen and minerals
what has flexible strength. LOSE= BRITTLE
collagen
hydroxyapetite is
minerals
what has weight bearing strength LOSE= bend
minerals
build matrix is what bone cell
osteoblast
what lays down new bone on surface (appositional)
osteoblast
osteogenesis/ ossification
osteoblast
what bone cell arises from osteochondral progenitor cells (stem cells)
osteoblast
what bone cell maintain matrix
osteocytes
what bone cell is 90-95% of bone cells
osteocytes
what arises from osteoblasts
osteocytes
what bone cells live long up to 25 years
osteocytes
what bone cell is found in lacunae and communicate via canaliculi
osteocytes
what bone cell breakdown matrix
osteoclasts
what bone cell has calcium into blood and arise in red bone marrow
osteoclast
when does ossification occur
- as fetus
- when grow
- when repair fracture
what are two bone types
woven and lamellar
what bone type is formed by osteoblasts to build stronger, more permanent bone
lamellar
what bone type is formed 1st by osteoblasts
woven
what bone type is weak due to random placement of collagen
woven
what breaks down woven bone
osteoclasts
what bone is arranged in concentric sheets/ layers
lamellar
what does a parallel arrangement usually mean
strong
what are final bone types
spongy and compact
what final bone appears porous, w more space
spongy
what final bone type has more bone matrix, dense, solid outer layer
compact
what final bone type has concentric rings of lamellae
compact
what final bone consists of trabeculae= interconnected rods
spongy
what final bone has osteon/ haversian system= unit
compact
main shaft of long bone
diaphysis
what is the diaphysis composted of
compact bone
what does the diaphysis have in the center
medullary cavity
what part of the long bone is at the ends and consists of mostly spongy bone
epiphysis
what is epiphysis bone covered in
articular cartilage
what is growth between 2 parts and occurs at both ends
epiphyseal plate
when growth is complete it is called
epiphyseal line
bone marrow red gives rise to and where
blood cells in the epiphyses
yellow bone marrow consists of what and where
adipose in diaphysis
what layer is in the inner surface and is bone cells
endosteum
what layer is in the outer surface and consists of dense irregular ct
peristeum
what layer helps with attachment and strengthen area for ligament/ tendon
sharpeys fibers
other bone types include
flat , short and irregular
spongy bone sandwhich is
flat
no diaphysis, small growth plates is
short and irregular bone
fetal ossification all derive from
mesenchymal ct
two categories for fetal ossification
intramembraneous and endochondral
intramembraneous fetal ossification includes what kind of ct
embryonic
endochondral fetal ossification includes what kind of cartilage
hyaline
when does intramembraneous ossification occur
embryo at 8 weeks to 2 y/o
where does endochondral ossification occur
base of skull, mandible area, clavicle epiphyses, rest of skeleton
intramembraneous ossification steps (3)
- osteoblast formation
- spongy bone formation
- compact bone formation
what is happening in osteoblast formation in intramembraneous ossification
mesenchymal cells- osteochondral progenitor cells - osteoblasts and become osteocytes. trabeculae of woven bone develop
what happens in spongy bone formation of intramembraneous ossification
osteoblasts present on trabeculae surface, cause it to become larger and longer. trabeculae join together to form spongy bone
what happens during compact bone formation during intramembraneous ossification
red bone marrow forms, as does peristeum. osteoblasts from periosteum lay down bone matrix to form compact bone. creates bone with outer compact bone and spongy in center
what are soft spots
fontanels
what is covered by membrane and bone fuse to cover and it allows brain growth and is usually complete in about 22 months
fontanels
5 steps of endochondral ossification
- cartilage model formation
- bone collar formation
- primary ossification center
- secondary ossification center
- adult bone
bones grow at the
epiphyseal plate
what connects diaphysis to epiphysis
metaphysis
what lay down new cartilage in epiphyseal plate
long bones
does bone growth occur at both ends
yes
when growing is done what happens
epiphyseal plate ossifies into epiphyseal line
remodeling occurs and is replaced every
10 years
genes determine
final height
other factors influence
expression
factors affecting bone growth is
nutrition and hormones
malnutrition means
shorter bones
what is needed for calcium absorption from intestinal area. you make or ingest it
vitamin d
lack of vitamin causes what in kids
rickets
what is rickets
bowed knees and joint inflammation
lack of vitamin d in adults result in
osteomalacia
softening due to calcium depletion is
osteomalacia
what is needed for osteoblasts to make collagen
vitamin c
deficiency in vitamin c results in
growth retardation
lack of vitamin c results in
scurvy
ulceration and hemorrhage, impaired would healing and teeth fall out is classified as
scurvy
xs hormones result in
gigantism
insufficient hormones result in
dwarfism
remodeling occurs throughout
lifetime
bone deposit consists of
osteoblasts
when does bone deposit occur
with bone injuries, need extra bone strength
bone resorption consists of
osteoclasts
Breakdown matrix where less Stress
bone resorption
remodeling is controlled via
(-) Feedback: Hormones (Blood Calcium Levels)
Calcitonin
C cells of Thyroid, (Osteoblasts Active, Bone Deposit)
PTH
(Osteoclasts Active, Release into Bloodstream)
Wolff’s Law
Bones Remodel in response to force/stress placed upon it.
BOTH …. & ……… ….. work hand in hand
hormonal and mechanical stress
determines WHETHER & WHEN remodeling will occur in
response to changing Blood Calcium Levels
hormonal
determines WHERE remodeling occurs.
mechanical
Mechanism of Fracture
Trauma, Pathologic, Periprosthetic (Plates Rods)
Soft Tissue Damage
Closed vs Open (Compound)
Displaced vs NOT
- Displaced (Bone ends NOT aligned)
Fracture Pattern
- Linear (Parallel to Bone length), Spiral (Twisting), Avulsion (Bone fragment), Stress (Hairline) from overuse, Compression (Weak = Collapses)
& Arrangement of Bone fragments
- Incomplete (Part of Bone) vs Complete vs Comminuted (multiple fragments)
Age Specific
- Kids (Greenstick = 1 side breaks, other bends), Epiphyseal Fracture- eneven growth
4 steps to repair damage
- Hematoma Formation
- Fibrocartilagenous Callus Formation
- Bony Callus Formation
- Remodeling
(~4 days) Mass of clotted blood at fracture site, Bone cells die due to
lack of nutrition, tissue becomes inflamed
Hematoma Formation
Soft granulation tissue; Capillaries & Phagocytes
into area Spongy bone forms; Callus splints bones (Ext & Int)
Fibrocartilagenous Callus Formation
(3-4 weeks to 2-3 months) Osteoblasts/Osteoclasts multiply;
Callus Spongy Bone
Bony Callus Formation
(Several months) XS material outside of bone & inside Medullary Cavity;
Compact Bone fixes shaft–. Like Original
Remodeling
bone heals with
xs strength
Fracture treated by
reduction
reduction is
realign fractured ends
repair for closed fracture
Ends together by Manual Manipulation.
repair for open fracture
Surgery Performed, Ends held together by Pins/Plates
Open Reduction Internal Fixation (ORIF)
External Fixation – Used when ORIF too dangerous,
Need 2nd surgery (once swelling improved),
Comminuted needing many pins to secure
Immobilize by Cast/Traction (8-12 weeks)
Cast – Plaster or FIberglass
XS Abnormal Bone Resorption & Formation
paget disease
pagets disease have a high ration of what to what
woven to compact
Bones become Soft & Weak, Decreased …….. Activity during pagets disease
osteoclast
Osteoblasts form what during pagets disease
Irregular Bone Thickness
pagets disease affect women and men over
40
where does pagets disease usually affect
spine, pelvis, femur, and skull
Weakened / Porous Bone- Deformity & Prone to Fracture
osteoporosis
causes of osteporosis
1.decreased Reproductive Hormone Level,
2. Inadequate Dietary Intake or Decreased absorption of Calcium,
3.Sedentary,
4.Disuse from Injury. Oophorectomy,
5. Cigarette smoking.
6. Proton Pump Inhibitors (PPI) for Acid Reflux use x5 years
osteoporosis affects
vertebral area, forearm, and pelvis
Decrease in Height, Kyphosis. is from
osteoporosis
Diagnosis for osteoporosis
DEXA scan = Dual Energy x-ray Absorptiometry
prevention for osteoporsis
- daily calcium
- dairy in diet
- vitamin d iu daily
- avoid high phosphorous foods
- avoid alc and caffeine
- weight bearing exercises
treatment for osteoporosis
- bisphophonates= osteoclast inhibitors
- estrogen like meds
- antibodies activate bone breakdown
- calcitonin replacement
- zoledronic acid (yearly shot)
