L42 - Intro To Bones And Joints Flashcards
What are the functions of the musculoskeletal system?
- support
- movement
- protection
- produces blood cells
- stores minerals
What are some structures of te muscoloskeletal system?
- bones
- muscles
- connective tissue (cartilage, ligaments, tendons)
What is bone like?
- exterios - compact
- interior - spongy
What are the different cartilages?
- fibrocartilage - intervertebral discs, menisci in joint spaces
- elastic - external ear, epiglottis, larynx
- hyaline - growth plate, joint surfaces, temporary scaffold
What is the function of bone?
- support
- protection
- muscle attachment
- mineral reservoir
- haematopoiesis
- lipid storage
- endrocrine
What is the function of cartilage?
- template for bone formation
- growth of long bones
- smooth
- articulating joint surface
What is water content like in bone vs cartilage?
- bone - 20-25%
- cartilage - 75-80%
- (%total wet weight)
What is composition like in bone?
- mineral - 65
- type I collagen - 30
- proteoglycans/glycoproteins - 5
- (%total dry weight)
What is composition like in cartilage?
- type II collagen - 65
- proteoglycans - 20
- glycosaminoglycans - 10
- glycoproteins
- 5
- (%total dry weight)
What are the different cell types in bone?
- osteoblasts (forming)
- osteocytes (abundant)
- osteoclasts (resorbing)
What are the different cell types in cartilage?
- chondroblasts
- chondrocytes
What is the anatomy of the skeleton?
- axial skeleton (bone of skull and vertebral column and ribs 80)
- appendicular skeleton (bones of limbs, pelvis, scapular and clavicle 126)
What is the classification of bones by shape?
- long bone
- short bone
- flat bone
- irregular bone
What is bone structure like?
- periosteum
- compact bone
- spongy bone
- bone marrow
- endosteum
What is compact bone like?
- outer layer of most bones
- composed of osteons
- provides strength and support
- site of muscle attachment
What is spongy bone like?
- inside bones
- lighweight, porous composed of trabeculae
- reduced the wight of bones
- contains bone marrow - blood cell formation
What are bone cells?
- osteogenic cells - progenitor cell
- osteoblasts - form bone
- osteocytes - mature bone cells that maintain bone tissue
- osteoclasts - destroy bone matrix
What is ossification?
Bone formation
What does the skeleton develop from?
- emrbyonic mesenchyme
- unspecialised cells in gel like matrix
- bones develop and replace existing structures
What is intramembranous ossification?
- cells aggregate in sites of bone development
- mesenchymal cells migrate and form condensations
- bone forms directly in condensation
What is endochondral ossification?
- cartilage template forms
- cartilage template is replaceed by bone
What are the different intramembranous ossification?
- formation of ossification centre
- osteocytes develop mineral salts - calcification
- formation of trabeculae
- development of periosteum, spongy bone and compact bone tissue
What are the steps in endochondral ossification?
- chondrocytes enlarge at centre of cartilage and die as matrix calcifies
- osteoblasts cover cartilage in thin bone layer
- blood vessels penetrate, form primary ossifcation center
- bone shaft thickends, cartilage neat epiphysis is replaced by shafts of bone
- blood vessels invade epiphyses and osteoblasts fom secondary centers of ossification
What is bone growth like appositional (width)?
- periosteum outside of bone contains osteoblasts that form new bone
- endosteum lines marrow cavity, contain osteoclasts that digest bone
- processes in balance so bone in in thickness and medullary cavity, inc in size
What is bone growth like interstitial (length)?
- at growth plate
- epiphyseal plate/growth plate made of cartilage
- new cartilage produced grows towards epiphyseal end, lenthening the bone
- cartilage dies, replaced by bone from diaphyseal end up
- continues until adulthood, cartilage replaced by bone, leaving epiphyseal line
What is maintenance of adult bone: remodelling?
- continuous process
- growth and repair
- calcium homeostasis
- involves osteoclast and osteoblast
- affected by hormones
What is bone loss in disease?
- osteoporosis
- decreased bone density
- post-menopausal women
- often no early symptoms
- more vulnerable to fractures
What are the types of bone fracture?
- transverse
- linear
- oblique, nondisplaced
- spiral
- greenstick
- comminuted
What are the bone regenerations: fracture healing?
- hematoma formation
- soft callus formation
- hard callus formation
- bone remodelling
What is hematoma formation?
Hematoma converted to granulation tissue by invasion of cells and blood capillaries
What is soft callus formation?
Deposition of collages and fibrocartilage converts granulation tissue to a soft callus
What is hard callus formation?
Osteoblasts deposits a temp bony collar around fracture to unite broken pieces while ossification occurs
What is bone remodelling?
Small bone fragments are removed by osteoclasts while osteoblast deposit spongy bone and then conver it to compact bone
What are joints?
where 2 or more bones meet, allow movement and structure stability
How are joints classified according to?
The range of motion they exhibit and type of tissue that holds the bone together
(Synovial, fibrous, cartilaginous)
What are synovial joints?
Diarthroses (allow free movement)
What are the 6 subtypes of synovial joints?
- planar
- hinge
- pivot
- condyloid
- saddle
- ball and socket
What is the structure of a synovial joint?
- articular cartilage
- synovial membrane
- synovial fluid
- joint capsule
- ligaments
- lacks blood vessels
- nutrients provided from synovial fluid
What is joint movement?
- 3 main axis (X, Y and Z)
- uniaxial, biaxial and polyaxial
What are the subtypes of synovial joint I?
- plane
- hinge
- pivot
