skeletal system Flashcards
3 functions of cartilage
- support soft tissues
- provide a smooth, gliding surface for bone articulations
- enable the development and growth of long bones
3 types of cartilage
- hyaline: most common, matrix contains moderate amount of collagen fibers
- elastic: matrix contains collagen fibers along with a large number of elastic fibers
- fibrocartilage: matrix contains limited number of cells and ground substance amidst a
substantial amount of collagen fibers
5 functions of bones
- supportive structures for the body
- protectors of vital organs
- reservoirs of calcium and phosphorus
- levers on which muscles act to produce movement
- containers for blood-producing cells
two types of bone
- compact (trabecular)
- spongy (cancellous)
5 types of bones
- long bones (tubular)
- short bones (cuboidal)
- flat bones
- irregular bones
- sesamoid bones (round or oval bones that develop in tendons)
(also accesory bones)
periosteum
covers all bones externally, has the unique capability of forming new bone
2 types of ossification (how bones are develloped)
- intramembranous ossification (mesenchymal models of bones undergo ossification)
- endochondral ossification (cartilaginous models of bones form from mesenchyme and
undergo ossification)
2 types of joints
- synovial joints (the skeletal elements are separated by a cavity)
- solid joints (ther is no cavity and the components are held together by connective
tissue)
3 characteristic features of synovial joints
- a layer of (hyaline) cartilage covers the articulating surfaces of the skeletal elements
- the presence of a joint capsule consisting of an inner synovial membrane and an outer
fibrous membrane - (not universal) presence of additional structures within the area enclosed by the capsule or synovial membrane (articular discs, fat pads, tendons)
bursae
closed sacs of synovial membrane outside the joints.
intervene between structures (tendons and bone, tendons and joints, skin and bone).
reduce friction of one structure moving over the other
tendon sheats
closed sacs of synovial membrane, surrounding tendons and also reducing friction
3 functions of articular discs
- absorb compression forces
- adjust to changes in the contours of joint surfaces during movements
- increase the range of movements that can occur at joints
fat pads
usually occur between the synovial membrane and the capsule and move into and out of regions as joint contours change during movement.
7 types of synovial joints based on the sape of their articular surfaces
- plane (flat)
- hinge
- pivot
- bicondylar (two sets of contact points)
- condylar (ellipsoid)
- saddle
- ball and socket
3 types of synovial joints based on movement
- uniaxial (movement in 1 plane)
- biaxial (movement in 2 planes)
- multiaxial (movement in 3 planes)
plane joints
allow sliding or gliding movement when one bone moves across the surface of another
hinge joints
allow movement around one axis that passes transversely through the joint, permit flexion and extension
pivot joints
allow movement around one axis that passes longitudinally along the shaft of the bone, permit rotation
bicondylar joints
allow movement mostly in one axis with limited rotation around a second axis; formed by two convex condyles that articulate with concave or flat surfaces
condylar joints (ellipsoid)
allow movement around two axes that are at right angles to each other; permit flexion, extension, abduction, adduction and cirumduction
saddle joints
allow movement around two axes that are at right angles to each other; the articular surfaces are saddle shaped; permit flexion, extension, abduction, adduction and circumduction
ball and socket joints
allow movement around multiple axes; permit flexion, extension, abduction, adduction, circumduction and rotation
solid joints
connections between skeletal elements where the adjacent surfaces are linked together either by fibrous connective tissue oor by (fibro)carilage.
Movement at these joints are more restricted than at synovial joints
3 types of fibrous joints
- sutures
- gomphoses
- syndesmoses
sutures
fibrous joints that occur only in the skull where adjacent bones are linked by a thin layer of connective tissue termed a ‘sutural ligament’
gomphoses
occur between the teeth and adjacent bone
syndesmoses
joints in which two adjacent bones are linked by a ligament
2 types of cartilaginous joints
- synchondroses
- symphyses
synchondrosis (with hyaline cartilage)
type of cartilaginous solid joints, occur here two ossification centers in a developing bone remain seperated by a layer of cartilage
symphyses (with fibrocartilage)
type of carilaginous solid joints, occur where two separate bones are interconnected by cartilage.
