Bones are livingtissues, made ofcells.They take innutrients anduse energy.They are ALIVE!
Made up of all the bones in your body.SkeletalSystem
Functions Of Skeletal SystemGive body shape and supportProtect your internal organsThey serves as an attachment point formuscles, helping them to move.Blood cells are made in the centre of bonesCalcium and phosphorous compounds arestored in bones for later use. They also makebones hard.
Bone Structure•Bones are not smooth.•They have bumps, edges, roundends, rough spots, and many pitsand holes.
Why the bumps and holes?•Muscles and ligaments attach to thebumps and pits.•Blood vessels and nerves enter andleave through the holes.
PeriosteumSurface of bone iscovered with a tough,tight-ﬁtting membrane
PeriosteumSmall blood vessels in periosteum carrynutrients into the boneCells for growth and repair of bone arefound here alsoUnder the periosteum are two types ofbone - compact bone and spongy bone
Compact BoneDirectly under the periosteum.Compact bone is hard and strong.Gives bones strength.Contains calcium and phosphate.Contains bone cells and blood vesselsIt is living. It is keeps bones from being toorigid, brittle or easily broken
Spongy BonesLocated at the ends of your long bones, like ourthigh and upper arm bone.Have many small openings to keep the bonelightweightThe centers of long bones have a large openingcalled a cavity.These cavities are ﬁlled with marrow.Marrow is also in openings of the spongy bone
MARROWYellow marrow contains fat cellsRed marrow produces red blood cellsHow long does it take to produce 2-3million red blood cells?1 Second
CartilageThe ends of bones are covered with a smooth,slippery, thick layer of tissue called cartilageCartilage does not contain blood vessels ormineralsFlexibleAbsorbs shocks in jointsMakes movement easier, reduces frictionCan be damaged
Bone Formation Beginning skeleton was made of cartilage. It gradually broke down and was replaced by bone. Osteoblasts (bone forming cells) deposited mineralscalcium and phosphorus in the bones, making thebone tissue hard. At birth you had 300 bones. You now have 206bones. How did you lose 94 bones?? Some fused, or grew together.
Osteoblasts build up bone.Osteoclasts….…break down bone tissue.This is normal and healthy.Osteoclasts release calcium and phosphorusinto the blood stream, which are needed tokeep your body working properly, includingmoving your muscles.
JointsAny place where two or more bones cometogetherThe bones are separated by cartilage and areheld together by ligaments