Chapter 5 - Bone Tissue Flashcards
(38 cards)
Function of skeletal system - storage of minerals
The Ca salts of bone represent a valuable mineral reserve that maintains normal concentrations of Ca and phosphate ions in body fluids
Ca is most abundant
Functions of skeletal system - support
Provides structural support for the entire body
Individual bones or groups provide a framework for the attachment of soft tissues and organs
Function of skeletal system - blood cell production
RBC, WBC, and platelets are produced in the red bone marrow which fills the internal cavities of many bones
Functions of skeletal systems - protection
Skeletal elements protect delicate tissues and organs
Ribs protect heart and lungs
Skull encloses the brain
Pelvis cradles the delicate digestive and repro organs
Functions of skeletal system - leverage
They can change the magnitude and direction of the forces generated by skeletal muscles
Long bone gross anatomy - diaphysis
Shaft
Long bone gross anatomy - epiphyses
Two ends of the bone
Long bone gross anatomy - metaphysis
A narrow zone inbetween diaphysis and epiphysis
Long bone gross anatomy - epiphyseal plate
A hyaline cartilage plate in the metaphysis at each end of a long bone that determines the future length and shape of the mature bone
Long bone gross anatomy - periosteum
Fibrous outer layer
Osteogenic inner layer
Isolates and protects the bone from surrounding tissues
Provides a route and a place of attachment for circulatory and nervous supply
Actively participates in bone growth and repair
Long bone gross anatomy - medullary or marrow cavity
The space within a bone that contains the marrow
Long bone gross anatomy- endosteum
Lines the medullary cavity
Contains osteoprogenitor cells
Covers the trabeculae of spongy bone and lines the inner surfaces of the central canals and perforating canals
Active during the growth of bone and whenever repair or remodeling is underway
Long bone gross anatomy - compact bone
Thickest where stresses arrive from a limited range of directions
Dense and solid
Lone bone gross anatomy. - spongy bone
Much more capable of resisting stresses applied from many different directions
Forms an open network of struts and plates
Blood and nerve supply of bone tissue - nutrient artery/vein
Form as blood vessels invade cartilage model at the start of endochondral ossification
Only one vein and one artery entering the diaphysis through a nutrient foramen
Blood and nerve supply to bone - periosteal vessels
Provide blood to the superficial osteons of the shaft
Blood and nerve supply to bone - metaphysis vessels
Supply blood to inner surface of each epiphyseal cartilage, where bone is replacing cartilage
Blood and nerve supply to bone - epiphyseal vessels
Supply the osseous tissue and medullary cavities of the epiphyses
Bone histology - compact bone
Haversian system
Central canal - contains the blood vessels that supply the Osteon
Concentric lamellae - form a series of concentric rings around the central canal
Lacunae
Osteocytes
Canaliculi
Bone histology - compact bone
Perforating canals ( Volkmann’s )
Extend roughly perpendicular to the surface
Bone histology - spongy bone
Trabeculae
Arrangement of spongy bone into parallel struts or thick, branching plates
Bone histology - spongy bone
Osteocytes
Mature bone cells
Maintain and monitor the protein and mineral content of the surrounding matrix
Steps of intramembranous ossification
- Fibrous connective tissue membrane
- Cells in membrane differentiate to osteoblasts
- Osteoblasts
- Secrete matrix called osteoid
5 when osteoblasts are enclosed by matrix = osteocytes - Bone matrix becomes mineralized and develops into trabeculae = spongy bone
- Fibrous membrane - periosteum
- Surface becomes compact bone
Steps to endochondral ossification
- Hyaline cartilage model
- Cartilage cells grow, increase size of model
- Bone forms on outer surface of cartilage shaft
- Near middle of model, bone cells differentiate into osteoblasts and produce new bone, produces primary ossification center
- Spongy bone filling central region of shaft is dissolved by osteoclasts to form marrow cavity
- Cells in epiphysis produce a secondary ossification center
- First and second primary ossification centers meet at epiphyseal plate
- Epiphyseal plate becomes epiphyseal line
- Oppositional growth at periosteal region
