lec 3 bone and joint basics Flashcards
modes of loading
tension compression bending shear torsion combine
shape categories of bone
irregular, flat, long, sesamoid, short
epiphysis
ends of long bone
only one in short bone
diaphysis
shaft of long bone
metaphysis
expanded flared end of shaft of long bone
medullary cavity
tube like area deficient of bone and filled with marrow
epiphyseal/growth plate
layer of cartilage that separates epiphysis and diaphysis
once growth stops its replaced by epiphyseal line
types of joints
synovial
nonsynovial- fibrous and cartiaginous
ends of bone covered in
hyaline cartilage
joint capsule made of
inner synovial membrane and outer fibrous membrane
synovial membrane
attaches at edges of articular surfaces
highly vascularized
secreted synovial fluid
fibrous membrane
provides integrity to joint
can thicken on outside to produce ligaments aiding in reinforcement
simple synovial joint
formed by 2 articular surfaces
compound synovial joint
formed by 3 or more articular surfaces ex:talus tibia fibula
complex synovial joint
possessing disc or meniscus ex: mandibular fossa, articular disc, mandibular condyle
composite synovial joint
combination of complex and compound
articular disc
made of fibrocartilage improves articulation absorb compression forces adjust to changes in contours of joint surfaces during movements increase range of motion
fibrous nonsynovial joints
bones joined by fibrous CT
ex: suture of skull, gomphosis, syndesmosis
cartilaginous nonsynovial joint
hyaline cartilage covered bones
ex primary: cartilage of growth plate of a long bone in subadult
ex secondary: pubic symphosis
translation
gliding motion in which bone slides on another &all points on moving object move same distance
nonaxial linear movement
rotation
motion in which angles b/t bone change ¬ all points on moving object move same distance
movement on one or more axises
joint surfaces curved
common in synovial joints only
intramembraneous ossification
certain flat bones
calcium directly deposited into mesenchymal precursor or model of bone
endochondral ossification
most bons
calcium deposited into cartilageneous model (precursor to bone)
stages of endochondral ossification
mesenchymal
cartilaginous(when joint forms)
osseous
mesenchymal stage
cells of limb bud are mesenchymal(undifferentiated loose CT from mesoderm)
cartilasginous stage/chondrification
mesenchymal cells begin to condense and differentiate into chondrocytes
chondrocytes form hyaline cartilage models that foreshadow the bones of extremities
osseous stage
blood vessels enter cartilaginous model bringing forth osteoblasts/bone progenitors and isolating growth of chondrocytes to ends
chondrocytes near diaphysis under hypertrophy and then die, mineralizing surrounding matrix
osteroblasts bind to mineralized matrix and deposit bone matrices
nonsynovial joint development
mesenchyme at the interzone differentiates into single layer of fibrocartilage
valgus
distal aspect of free limb is bent or twisted outward away from midline of limb or body
varus/varum
twisted toward midline
hallux valgus
bunion
proximal phalynx of big toe deviated laterally to long axis of 1st metatarsal
hallus varus
the long axis of proximal phalanx will be deviated medially relative to long axis of 1st metatarsal
