L43 - 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