endoskeltons- inside the flesh
exoskeltons- outside the flesh
endoskeltons have an advantage over the exoskeltons
endoskeltons- does not restrict growth, usually lighter and smaller, is a framework for easy attachment of muscles, allows flexibilty, grows with the body.
exoskeltons- the body inside can increase it number of cells but not size, has to be shed to allow the body inside to grow.
humans- made from bone and cartilage- living tissues- susceptible to infection but can grow and repair themselves.
bones start of as cartilage-stages of this-
cartilage is relaced gradually by addition of calcium and phosphorus- ossification
growth spurt in adolescence- cartilage at the ends of long bones produces more bones
most of cartilage has been turned into bone- stopped growing- docs can tell if a person is still growing by the amount of cartilageis still there.
long bone structure structure (hollow) consists of-
a head covered with cartilage
a shaft containing bone marrow with many blood vessels
hollow structure- stronger than solid bones of the same mass.
a sharp knock- break a bone
broken bone- called a fracture
simple fractires- involves only bone
compound fractures- involves other tissues as well as skin
it is dangerous to move a person with a suspected fracture becuase the broken bones could pierce another organ or even sever the spinal cord. this could result in paralysis.
osteoporosis is a disease- suffered mainly by elderly
caused by- loss of minerals from bone- through poor diet or lack of exercise-makes bones soft- more susceptible to fractures.
synovial joints are movable and allow diiferent degrees of movement.
type of synovial joint- ball and socket- in shoulder and hip- degree- rotational
type of synovial joint- hinge- elbow and knee- degree- movement in one plane
part of synovial joint- synovial fluid- lubricates the moving surfaces reduces friction
part of synovial joint- synovial membrane- secretes synovial fluid, keeps fluid within the joint
part of synovial joint- cartilage-reduces friction
part of synovial joint- ligaments-attach bone to bone and keep joint together
many joint diseases- pain and restricted movement for sufferer
can replace hip and knee joints with artificial joints
many disadvantages and advantages-
quick recovery, free from pain, regain mobility, more active, allows independence, improved medical and mental health and finally new joints last longer and are not rejected.
cannot be used where the joint is diseased and some people are not able to withstand surgery.
pull a bone to move it when they contract.