Module 24 - Bone Tissue Flashcards
give the classification of bone tissue
Organization of collagen fibres within the bone matrix
Woven Bone
Randomly oriented collagen fibres (development and repair)
Remodeled
Lamellar Bone
Mature bone organized in sheets or layers (lamellae)
give the types of lamellar bone
spongy (or cancellous or trabecular) bone and compact (or cortical) bone
describe spongy bone
provides strength without extra mass, smooth outside because of compact bone
describe compact bone
what is trabeculae
connecting rods or plates in spongy bone
describe spongy bone
From distal to proximal, describe the compact/cortical bone
medullary cavity > spongy bone > compact bone > periosteum
list the different lamellae
interstitial, outer/inner circumferential, concentric lamellae
in compact bone, the blood goes through the…
perforating and central canals
what are the 2 components of the periosteum? describe them.
Inner Osteogenic Layer: Contains osteoblasts and osteoprogenitor cells; responsible for bone growth, repair, and remodeling; located close to the bone surface.
Outer Fibrous Layer: Made of dense, tough connective tissue; provides attachment for tendons and ligaments; protects the bone and connects it to surrounding structures.
differentiate outer and inner circumferential lamellae
Outer Circumferential Lamellae: Located around the outer perimeter of the bone, just beneath the periosteum; provide structural support to the entire bone.
Inner Circumferential Lamellae: Located near the inner surface of the bone, adjacent to the endosteum; support the inner cavity of the bone.
what is concentric lamellae
Concentric Lamellae: Circular layers surrounding each osteon (central canal); provide strength to resist twisting and bending.
what is interstitial lamellae
Interstitial Lamellae: Irregularly shaped layers filling spaces between osteons; remnants of old osteons broken down during bone remodeling.
central or haversian canals are ________ to long axis
parallel
what is lamellae
rings of calcified matrix
central canals are connected by _____ canals
perforating/Volkmann
the endosteum lines the _____
medullary cavity
the periosteum is the ____ layer while the endosteum is the ___ layer
outer, inner
The central (Haversian) canals are unique to compact bone, as they run through osteons to provide blood and nutrients, a feature not present in the spongy (cancellous) bone structure.
Osteons are NOT found in spongy/cancellous bones
what is an osteon
An osteon is the basic structural unit of compact bone, consisting of concentric layers of calcified matrix (lamellae) arranged around a central (Haversian) canal. This canal contains blood vessels and nerves, providing nutrients and support to bone cells (osteocytes) within the osteon.
in a long bone, the shaft is called the…
diaphysis
in a long bone, the end of the bone is called the…
epiphysis
in a long bone, what is between the epiphysis and the diaphysis
metaphysis
what is the epiphyseal plate
Hyaline cartilage - present until growth stops.
The epiphyseal plate, also known as the growth plate, is a layer of cartilage found at the ends of long bones in children and adolescents. It allows bones to grow in length and eventually hardens into solid bone once growth is complete.
what is the medullary cavity in long bones
children - red marrow
Maturation - changes to yellow marrow in long bones and skull (except for proximal epiphyses of long bones)
how do bones develop
through osteogenesis or ossification
how do bones begin their development
Begins in embryo at ~8 weeks : mesenchyme becomes osteochondral progenitor cells
*due to expansion of blood vessels
differentiate intramembranous ossification and endochondral ossification
intramembranous ossification and endochondral ossification produce what type of bone
woven bone to be remodeled
bone growth doesnt include…
interstitial bone growth
bone growth has what type of growth
appositional growth
what is the zone of Resting cartilage
Zone of Resting Cartilage: Slowly dividing chondrocytes
what is the zone of proliferation
Zone of Proliferation: New cartilage is produced on the epiphyseal side of the plate as the chondrocytes divide and form stacks of cells
what is the zone of hypertrophy
Zone of Hypertrophy:
Chondrocytes mature
and enlarge
what is the zone of calcification
Zone of Calcification: Matrix is calcified, and chondrocytes die
what is an ossified bone
Ossified bone: The cartilage on the diaphyseal side of the plate is replaced by bone.
explain growth in bone thickness
explain bone remodeling
