Bone And Soft Tissue Flashcards
Joints
A point where 2 separate bones meet
MSk system is made up of what
Bone
Muscle
Connective tissue ( tendon , ligaments, cartilage)
How many bones in adults
206 and sesamoids
How many bones in children
270
Appendicular Skelton
Pectoral girdle
Upper and lower limbs
Pelvic girdle
Axial skeleton
Cranium
Vertebral column
Rib cage
Functions of skeleton
Support Protect vital organs Movement - works with muscles Mineral storage ( stores calcium and phosphate) Produces blood cells ( bone marrow)
How do flat bones develop 8n uterine
Intramembranous ossification
How do long bones develop in utero
Endochondral ossification
Flat bones
Skull
Clavicle
Mandible
Process of untramembranous ossification ( mesenchymal to bone )
Mesenchymal cells condense
Osteogenesic precursor cells prolif
Precursor cells differentiate into osteoblasts
Osteoblasts form ossification centres and begin to secrete Osteoid
( trapped osteoblasts become osteocytes)
Osteoid become mineralised
Trabecular matrix and periosteum forms
Compact bone develops superficial to cancellous bone
Crowded blood vessels condense into red bone marrow
Endochondral ossification
Mesenchymal cells aggregate
Formation of cartilage model
Bone collar and primary ossification centre in diaphysis develop
Fuormation of marrow cavity
Epiphyseal cartilage comenses ossification
Ossification of lower epiphyseal plate commences
Disappearance of epiphyseal cartilage - cessation of bone growth
Which form on embryo logical bone growth takes longer
Endochondral
What are bones made up of
Cells and matrix
Bone cells
Osteogenic
Osteoblasts
Osteoclasts
Osteocytes
Osteogenic
Bone stem cell
Found in deep layers of periosteum ( outer part of bone)
Osteoblasts
Bone forming
Secrets Osteoid
Catalyse mineralisation of Osteoid
Growing portions of bone , including periosteum and endosteum
Osteoclast
Bone breaking
Dissolve and resorb bone by phagocytosis
Found at bone surfaces and at sites of old , injured or unneeded bone
Osteocytes
Mature bone cell
Formed when an osteoblasts becomes imbedded in the secretions
Sense mechanical strain to direct osteoclast and osteoblasts activity
Found in matrix
Which type of bone cell forms the majority of bone
Osteocyte
Bone matrix contents
Organic ( type 1 collagen and ground substance )
Inorganic ( calcium hydroxyapatite and osteocalcium phosphate)
What does ground substance made up off
Proteiglycans
Glycoproteins
Cytokines and growth factors
Two types of mature bone
Cortical
Cancellous
Cortical bone
Compact and dense
Suitable for weight bearing - normally on outside
Cancellous
Spongy like honeycomb structure and not suitable for weight baring - has lots of air
Normally found on inside of bone
Osteon
A compact/ cortical bone contains Osteoid
Structure of osteon
Few spaces
Provides protection , support and resists stresses produced by weight of movement
Concentric lamellae around the Haversian canal
Haversian canal
Contains blood vessels, nerves and lymphatic
Lacunae
Small spaces containing osteocytes
Tiny vanalicullitqdiqte from lacunae filled with extra cellular fluid
Folks and canal - transverse perforating canals
Two types of bone growth
Interstitial
Appositional
Interstitial growth
Growth of long bones
Increased length
Appositional growth
Healing bones after fracture
Increase thickness and diameter
Interstitial growth
Happens at physeal plate
Zone of elongation in lone bone
Contains hyaline cartilage
Epiphyseal side- hyaline cartilage active and dividing to form hyaline cartilage matrix
Diaphyseal side - cartilage calcifies and dies and then replaced by bone
Appositional growth
Deposition of bone beneath the periosteum to increase thickness
1) ridges in periosteum create groove for periosteal blood vessels
2) periosteal ridges fuse, forming an endosteum lined tunnel
3) osteoblasts in endosteum build new concentric lamellae inward toward center of tunnel forming a new osteon
Bone grows outwards as osteoblasts in periosteum build new circumferential lamellae
Osteon formation repeats as new periosteal ridges fold over blood vessel
Fibrous joints
Sutures
Syndrsmosis
Interosseaous membrane
Cartiag8nous joints
Synchondroses e.f. Spine
Symphses eg. Pubic
Synovial joints
Plane Hinge Condyloid Pivot Saddle Ball and socket
Ball and socket joints
Multi axphyseal joint as the bone can move in all 3 planes , x , y and z
Synovial
Hinge joint
Joint only moves in one plane - e.g. elbow
Synovial
Knee joint
Modified hinge joint
Primary movement is flex ion and extension but can ,I’ve in other planes like callus and varies and external rotation
Synovial
Why is the knee a synovial joint
Does have cartilage but cartilage is incomplete and doesn’t produce the junction in between bones and just reduces pressure between bones by increasing SA
Synovial joints
Most common
Most mobile
Joint capsule ; articulated capsule ( outer) keeps bones together structurally Synovial membrane ( inner) contains synovial fluid which reduces friction during movement
How are synovial joints stabilised
Muscles/tendons
Ligaments
Bone surface congruity
Ligaments and joint stability
Ligaments prevent excessive moveemnt that could damage joint
More ligament and together ligaments - greater stability but less mobility
Less ligaments and laxer ligaments - greater mobility and less stability
Rotator cuff muscles
Supraspinators
Infraspinatos
Sub scapular is
Teres minor
