Skeletal system Flashcards
Name the 6 functions of the skeletal system
Support, protection, movement, mineral storage and release, site of blood cell production, triglyceride storage system
Long bones characteristics
Long cylindrical shaft
Relatively wide protruding ends
Central area of shaft contains marrow
E.g tibia
Flat bones characteristics
Usually have curved surface vary from thick to thin
Protective and offer large areas for muscle attachments
E.g scapula, sternum
Short bones characteristics
Small, cubical shaped, solid bones
Similar in length, breadth and thickness
E.g carpals
Irregular bones characteristics
Have specialised shapes and functions
E.g vertebrae
Sesamoid bones characteristics
Small bones embedded within tendon where pressure develops
Provide protection for tendon, change angle of insertion of muscle and improv mechanical advantage
E.g patella
Structure of long bones
- Diaphysis: shaft/long portion of the bone
- Epiphysis: Round end of the bone
- Metaphysis: Wider portion of long bone adjacent to epiphyseal plate
- Epiphyseal growth plate/disks: Hyaline cartilage plate in the metaphors at each end of a long bone- responsible for growth in the length of the bone
- Articular cartliage: thin layer of cartilage covering the epiphysis. Cartliage decreases friction
- Periosteum: outer surface of a bone lined by a thin layer of connective tissue
- Endosteum: Thin layer of connective tissue that lines the walls of the medullary cavities
- Medullary cavity: contains the yellow bone marrow
Bone marks that form joints
Condyle - rounded projection, usually articulates with another bone
Facet - small, flat or almost flat surface
Head- prominent rounded projection at proximal end of bone, usually articulates
Crest
Prominent ride of bone
Epicondlye
Projection located above condyle
Line
A long thin, projection often with a rough surface.
Process
Prominent projection
Spine
Sharp, slender projection
Trochanter
Very large blunt projection
Tubercle
Small round projection
Tuberosity
Large round, roughened projection
Foramen
rOUNDED HOLE OR OPENING IN BONE
Fossa
Hollow, depression, flattened surface
Osteogenic cells
Unspecialised cells found in periosteum, endosperm and canes that contain blood vessels
Possess mitotic potential and have ability to develop into osteoblasts
Osteoblasts
Associated with bone formation
Produce and secrete collagen and other organic components to build bone tissue
Ossifies and found on surfaces of bone
Stress and fractures stimulate this process
Osteocytes
Mature bone cells derived from osteoblasts- principal cells of bone tissue
Osteoblasts that become isolated within the bony intercellular substance that deposit around themselves and whose structure changes
Osteoblast initially form bone, osteocytes maintain daily cellar activities of bone tussle.
Osteoclasts
Bone destroying cells
Develop from circulating monocytes
Settle on surface of bone where involved in bone resorption/destruction of matrix which is important for development, growth, maintenance and repair of bones
Compact bone tissue
Contains few spaces
Layer over the spongy bone tissue
Forms external layer of all bones of body and makes up bulk of diaphysis of long bones
Ptotetion, support, resists stress of weight on long bones
Central canals run longitudinally through bone and are surrounded by lamellae
Small spaces between lamellae called lacunae which contains osteocytes
Spongy bone tissue
Internal to compact
Short, flat, irregularly shaped bone so high incidence of fracture in elderly
Consists of irregular latticework of thin plates of bone
Blood circulates through marrow cavities in spongy bone providing nourishment for osteocytes
Remoddelling of bone
The replacement of old bone tissue by new bone tissue. Compact bone is formed by the transformation of spongy bone
Large amounts of bone removed through resorption (osteoclasts) and replaced through bone deposition (osteoblasts)
Wolff’s law
States that bone in a healthy person or animal will adapt to the lands it is placed under
i.e if increase loading, bone remodels over time, increase bone deposition and increase strength to resist the load
Bone tissue and exercise
Bone strength increases with mechanical stress e.g pull of skeletal muscle and gravity
Increase mental salt deposits
Production of collagen fibres
Walking and moderate weight lifting help to build and retain bone mass
Development of bone in children
Bone diaphysis and epiphysis joined by cartilaginous plates called epiphyseal or growth plate
Eventually fuse together and replaces with bone
