Introduction to Bone and Soft Tissue Flashcards
How is the musculoskeletal system divided into
What does the human skeleton consist of
206 bones in adults
270 in children
What are the functions of the skeleton
Support - helps you stand up
Protection - protects your vital organs
Movement - works with muscles so you can get around
Mienral storage - stores calcium and phosphate
Produces blood cells - bone marrow
What is the process of endochondral ossification
Hyaline cartilage formed from chondroblasts
Development of long bone from hyaline cartilage
Forms a ring of tissue around it - perichondrium
Condrocytes forms a calcified matrix
Matrix forms a primary ossification center with a nutrinet artery-centre of long bones
End of long bones - secondary ossification center
Junction between secondary and primary is epiphyseal plate
What are bones made up of
Cells
Matrix
Type of bone cells
Osteogenic cells - stem cell
Osteoblast - bone forming, secreted asteoid, catalyse mineralilsation
Osteocyte - Mature bone cell and formed when osteoblast becomes imbedded in its secretions, sense mechanical strain
Osteoclast - Bone breaking, phagocytosis of bone, derived from bone marrow
Where do you fine bone cells
Osteogenic cells - deep layers of periosteum
Osteoblast - growing portions of bone, periosteum and endosteum
Osteocytes - entrapped in matrix
Osteoclasts - bone surfaces and at sites of old, injured or unneeded bone
Composition of bone matrix
What are the bone types
Immature bone - first bone that is produced, laid down in a woven manner, mineralised and replaced by matured bone
Mature bone - mineralized woven bone, lamellar structure. relatively strong
Cortical mature bone - dense, suitable for weight baring
Cancellous mature bone - spongy honeycomb, not suitable for weight baring
Diagram of cancellous bone
Organisation of compact/cortical bone: osteons
Haversian Canal: Vertical structures containing artery, vein, lymphatic system
Surrounding the bone are concentric lamellae laid down by osteoblast
Become osteocytes when they get trapped
In between the haversion systems are the volkmans canals
Lacunae - small spaces containing osteocytes
Structure of long bone
How do bones growth
What happens in interstital growth
Happens at the physis (physeal plate)
Zone of elongation in long bone
Contains hyaline cartilage
What happens in appositional growth
Deposition of bone beneath the periosteum to increase thickness
Ridges in periosteum create groove for blood vessels
Periosteal ridges fuse forming endosteum-lined tunnel
osteoblasts build new concentric lamellae inward towards center of tunnel forming a new osteon
How does calcium hydroxyapatite help
Structural support
How do we classify joints
Fibrous - radius and ulna, tibia and fibia, skull (sutures, syndesmosis, interosseous membrane)
Cartilaginous - integral struture, synchondorses eg spine, symphyses eg pubic
Synovial - most common
Functional types of synovial joints
Plane
Hinge joint - only move in one plane
Condyloid
Pivot
Saddle
Ball and socket
What are the characteristics of a synovial joint
Characteristed by joint capsule
Articular capsule - outer
Synovial membrane - inner
Synovial fluid into synovial cavity - secreted by synovial membrane and hyaline cartilage
Low friction high lubrication
How are synovial joints stabilised
Bone surface congruity - stable between bones
Ligaments - stop bones moving from extreme directions - (MORE stability LESS mobility), poor stability, risk of dislocation, excessive ligament laxity - hypermobility - greater risk of injury
Muscles - tendons can stabiles
Comparison of hip and shoulder stability
What is the process of intramembranous ossification
Initiated by mesenchymal stem cells
Differentiate into osteoblasts
Osteoblast lay down osteoid - trapped
Osteoid calcifised form spicules which form trabeculae
Blood vessels condense and for periosteum - fibrous sheet that covers bone
Formation of lamellar bone formed around spongey bone. Has regular alignment of collagen
