bone and cartilage Flashcards
what is a eurypholus
bony fish
what is a hybodus
cartilaginous fish
what are the roles of periosteum
1 major role in bone formation 2 tendons, ligaments and joint capsules attach to it not directly to bone. 3 carries blood vessels and nerves 4 major role in bone repair post fracture
what is the epiphysis
found at the end of a long bone after the diaphysis
what is the diaphysis
shaft, cylindrical and narrow
where is the endosteum found
lining marrow cavity
what is the bone made up of
cancellous/spongy/trabeculae/with spicules
how is a fracture created
mineral shears at 45degrees in compression, collagen snaps transversely in tension, torsion creates a helical fracture, bending causes compression and tension on opposite sides
what is a mesenchyme cell
undifferentiated fetal connective tissue
what are chrondoblasts and osteoblasts
active cells that can lay down membrane cartillage
what are chrondocytes and osteocytes
resting in lacunae
what are the functions of bone 9
1 struts, 2 levers 3 protects 4 elastic potential energy store 5 acoustic 6 display 7 combat 8 blood cell prod 9 mineral store
describe the features of cartilage
firm extracellular chondrin matrix, sulfated mucopolysaccharide gel + network of type 2 (UNUSUAL) collagen fibres
what is cartilage described as
reinforced concrete - gel resists tension and fibres resist compression
what is cartilage laid down by
chrondoblasts
where are resting chrondrocytes
in 2-4 cell colonies in lacunae, no nerves, rarely blood vessels, often surrounded by perichondrium
types of cartilage
hyaline skeletal, elastic skeletal, fibrocartilage skeletal, articular and hyaline model precursor
what is hyaline skeletal
simplest, may mineralise, found in upper respiratory tract, ventral ribs
what is elastic skeletal
contains elastin fibres too as in the external ear, upper respiratory tract
what fibrocartilage skeletal
alternating layers of hyaline cartilage and collage found in intervertebral discs, scuta, labra, menisci and discs
what is articular cartillage
complex partly fibrous/ partly hyaline from
what is hyaline model precursor
for bone development
describe the structure of long bones
constantly remodelled, yielding many parallel cylinders called OSTEONS
what is an osteon made up of
concentric cylinders of matrix interspersed with lacunae
what does each lacunae contain
a resting osteocyte, they are stellate with radiating tiny canniculi permeating bone containing cytoplasmic processes
each osteon is based around….
a haversian canal (osteoclast erosion). the cannal carries vessels and nerves and connects to the marrow cavity
osteons are connected by
oblique volkmanns cannal
what is the appearance of red marrow and air space
haemopoietic
what is the appearance of yellow marrow and air space
adipose
what is pneumatised marrow
full of air e.g. vulture metacarpus
describe the osteoid matrix
1/3 organic type 1 collagen and 2/3 hydroxyapatite with adsorbed calcium carbonate
what is the bone composition
varies from rigit but btrille to more flexible
what did the bone evolve as (purpose)
phosphate store - unpredictable levels in the sea water e.g. decrease after algal blooms
what are osteoclasts
myeloid blood cell derived, multinucleate up to 0.15mm, short lived > 10 days.
what is bone formation/destruction controlled by
hormonally by parathyroid hormone, calcitonin and vitamin D
how can location classify bone
axial and appendicular, cranial and post cranial
how can morphology classify bone structure
long, short, flat, irregular, sesamoids
how can embryology classify bones
somatic = sclerotome and body wall. visceral. sesamoids.
how can tissue of formation classify bones
endochondral e.g. long bones or membrane e.g. skull flat bones
what are the long bones blood supply
periosteal aa, epiphyseal aa, metaphyseal aa
what is membrane bone?
evolutionary distinct from fish, devolpmentally distinct due to forming in condensed sheets of fibrous tissue. cancellous bone + marrow sandwiched between two layers of compact bone and periosteum
causes of fracture
external trauma (can occur anywhere) or internal mechanical overload trauma (specific)
which fractures are more important
cortical more important than cancellous except vertebral compressions and implant stability
which is stronger mineral or collagen
mineral is stronger in compression than collagen in extension
how does bone exhibit anistrophy
stronger in direction parallel to osteons
