Skeleton and joints Flashcards
Definition of head
Expanded end of epiphysis separated from shaft by narrow neck
Definition of neck
Narrow connection between epiphysis and diaphysis
Definition of condyle
Smooth rounded articular process
Definition of trochlea
Smooth grooved articular process shaped like a pulley
Definition of facet
Small flat articular surface
Definition of process
Projection or bump
Definition of ramus
Extension of bone at an angle to rest of structure
Definition of trochanter
Large rough projection, femur only
Definition of tuberosity
Relatively small roughened projection
Definition of tubercle
Small rounded projection
Definition of crest
Prominent ridge
Definition of line
Low ridge
Definition of fossa
Shallow depression
Definition of sulcus
Narrow groove
Definition of foramen
Hole
Definition of fissure
Narrow cleft
Meatus/canal
Passageway through bone
Definition of sinus/antrium
Chamber within bone
Definition of joint
Union between 2 bones, do not necessarily imply movement, some are specialized to permit little/no movement
Definition of uniaxial
1 axis of rotation
Definition of biaxial
2 axes of rotation, perpendicular
Definition of multiaxial
3 axes of movement
Definition of nonaxial
All directions of movement
Composition of skeletons
Cartilage and bone (rigid tissue)
Only bone is mineralised
Composition and structure of cartilage
Consists of chondroblasts
Chondroblasts secrete ground substances and collagen to form rigid gel
Remain in situ as chondrocytes
No neuromuscular elements, v thin areas
How does cartilage gain nutrients
Diffusion through ground substance, remain in adults as articular surfaces where rigidity, elasticity needed
Functions of the bone
Support Movement Protection Haemopioesis Storage for calcium and phosphorus
How does bone provide support
Rigid framework for body surfaces
How does bone provide movement
Acts as levers for muscles
How does bone provide protection
Form box to protect delicate structures
How does bone provide storage for calcium and phosphorus
Calcium in blood must be kept constant, must be stored until required so bone constantly being remodeled
Calcium needed for many functions
Classification of bone by region
Axial skeleton, skull, ribs, spine
Appendicular skeleton, limbs and pelvis
Classification of bone by shape
Long Flat Irregular Short Sesamoid
Parts of long bone
Epiphysis
Metaphysis
Diaphysis
Compact bone
Spongy bone
Articular cartilage
Endochondral ossification and what forms
Long bone
Surrounds hyaline cartilage with periosteum, calcifies and dies
Intramembranous ossification and what forms
Flat bones
Structure is the same as endochondral
Structure of mature bones
Compact bone
Trabecular (spongy bone)
Structure and properties of compact bone
External bone surface Blood vessels supply osteon Perforating canals deliver blood deeper Resist stresses from some directions Thickest where forces are greatest
Structure and properties of trabecular bone
Struts and plates, lighter
Strong enough to resist forces (movement generated force, gravity)
Found along epiphysis, aligned along stress lines and cross bracing
Protects bone marrow
Classification of joints
Fibrous
Cartilaginous
Synovial
Types of fibrous joints
Sutures, between skull bones
Syndesmoses, interosseous membrnaes
Gomphoses, collagen between teeth and bones
Why use sutures
Babies don’t have sutures, skull plates not joined, can pass through birth canal
Collagen forms between plates, rigid, no movement
Types of sutures
Squamous
Serrated
Denticular
Uses of syndesmoses
Collagenous interosseous membranes, keep slightly separated bones together
Very litte movement
Uses of gomphoses
Peg in a socket
Tooth in periodontal ligament
Can act as shock absorber
Types of cartilaginous joints
Synchondroses
Symphyses
Uses and properties of synchondroses
Between bones of endochondral origin
Solid hyaline cartilage between opposing surfaces
Acts as epiphyseal plate between primary and secondary ossification centers
Area for growth
Uses and properties of symphyses
Partially moveable joint
Opposing surfaces covered in hyaline cartilage but separated by fibrous tissue
Found in midline of body
Structure of synovial joints
Moveable with 4 common features and 2 occasional features
Bone ends covered in articular hyaline cartilage
Presence of joint cavity
Joint capsule
Synovial membrane
Disc
Bursae
Properties of articular cartilage
Tough and deformable, surface adapts when forces applied
Can recoil when force removed
No blood/nerve supply
Prevents stress generation bone, too rigid
Properties of joint cavity
Bone ends separated by cavity, fluid filled
Properties of joint capsule
Surrounds joint, encloses it
Consists of collagen fibre bundles, vary in tautness/thickness
Ligaments=thickening of capsule
Properties of synovial membrane
Lines capsule, has rich capillary network
Can secrete and absorb fluid, nutrients can diffuse into cartilage
Viscosity can change, with speed of movements
Properties of disc
Between articular surfaces, divide into 2 cavities
Increase movement range at joint
Can spread load over whole joint surface
Properties of bursae
Synovial fluid sacs, close to joint
Occur when structures are in tight opposition to each other
Classification of synovial joints
Hinge Pivot Ball and socket Saddle shaped Ellipsoid Condyloid Plane
Movements of the joints
Depends on shape of joint surfaces, joint capsule tension, position of capsular ligaments
Concentric muscle contraction, provide primary movement
Eccentric muscle contraction, provide limited movement
Axis of rotation
Uniaxial
Biaxial
Multiaxial
Nonaxial