4 What the Skeletal System Does Can a building stand without a frame?
5 Five major skeletal functions Just as a building cannot stand without frame you would collapse without your skeletonFunctionsProvides shape and supportEnable you to moveProtects your organsProduces blood cellsStores mineral and other materials until your body needs them
6 Shape and SupportThe skeleton provides a framework that supports and protects many other body partsThe backbone or vertebral column is the center of the skeletonThe bones in the skeleton are in some way connected to this columnYou can feel 26 small bones if your move your fingers down the center of your backBend forward at the waist and feel the bones adjust as you moveThink of each individual vertebra as a bead on a string it is flexible and able to bend
7 Production and Storage of Substances Some of your bones produce substances that your body needsThe long bones of your arms and legs can be thought of as factories that make certain blood cellsBones also store minerals such as calcium and phosphorusWhen the body needs these minerals the bones release small amounts of them into the blood
8 Joints of the SkeletonJoints allow bones to move in different ways as they are the place in the body where two bones come togetherThere are two kinds of jointsMovable and immovable joints
9 Immovable Movable Joints Some joints in the body connect bones in a way that allows little or no movementBones of the skull are held together by immovable jointsMost joints in the body are movable they allow the body to make a wide range of movementsMovable joints are held together by connective tissues called ligamentsThey also have a second type of connective tissue called cartilage which is more flexible than bone
10 Movable joints Hinge Joint-allows forward or backward motion Your knee is a hinge joint as well as your elbow
11 Ball and Socket Joint Allows the greatest range of motion The ball and socket joint in your shoulder allows you to swing your arm freely in a circleHips also have ball and socket joints
12 Pivot Joint Allows one bone to rotate around another Pivot joint in your neck allows you to turn your head from side to side
13 Gliding Joint Allows one bone to slide over another Your wrist or ankle enables you to bend and flex as well as make limited side to side motions
14 CartilageCovers the ends of the bones and keeps them from rubbing against each other
15 Bones-Strong and Living Bones are complex living structures that undergo growth and developments
16 Bone Structure (1)Femur is the body’s longest bone and connects the pelvic bones to the lower leg bonesA thin tough membrane covers all of the bone except the endsBlood vessels and nerves enter and leave the bone through the membraneBeneath the bones outer membrane is a layer of compact bone which is hard and dense but not solid
17 Bone Structure (2) Small canals run through the compact bone These canals carry blood vessels and nerves from the bone’s surface to the living cells within the boneJust inside the compact bone is a layer of spongy bone
18 Spongy Bone Like a SPONGE, spongy bone has many small spaces within it This spongy structure makes spongy bone tissue lightweight but strongIt is also found at the ends of the boneSpaces in the bones contain a soft connective tissue called marrow
19 Two types of Marrow Red and Yellow Red bone marrow produces some of the body’s blood cellsAs a child most of your bones contain red bone marrowAs a teenager only the ends of your femurs, skull, hip and breastbone contain red marrowOther bones contain yellow marrowThis marrow stores fat that can serve as an energy reserve
20 Bone StrengthThe structure of bone makes it both strong and lightweightThey are so strong they absorb more force without breaking than can concrete or granite rockBones are hard because they contain minerals-phosphorus and calciumYou can jump up and down or turn cartwheels without breaking bones
21 Bone Development The tip of your nose contains cartilage As an infant much of your skeleton was cartilageOver time the cartilage is replaced with hard bone tissueThis replacement of cartilage by bone tissue usually is complete by the time you stop growing
22 Bone GrowthBones are alive-they contain cells and tissues such as blood and nervesThey also form new bone tissue as you grow as they are aliveEven after you are grown however, bone tissue continues to form within your bones
23 Taking care of your bones A combination of a balanced diet and regular exercise are important for a lifetime of healthy bonesDiet and exercise are some ways of taking care of your bones
24 OsteoporosisAs people become older their bones begin to lose some of the minerals they containMineral loss can lead to osteoporosis a condition in which the body’s bones become weak and break easilyIt is more common in women than men
25 1. What are five functions of the skeleton? Provide shape and supportEnable you to moveProtect your organsProduce blood cellsStore minerals and other materials
26 2. What are four types of movable joints? HingeBall and socketPivotgliding
27 3. What are three types of tissue in bone? Compact boneSpongy boneMarrow
28 4. Which function of the skeletal system gives you a clue that bones are not dead or solid? Bones make certain blood cells and release small amounts of minerals into the blood when needed.
29 5. Where is marrow produced? In the spaces in bone
30 6. Does new bone tissue stop forming after you stop growing? No, bones make new tissue when they absorb the force of your weight and when a bone has broken
31 7. What do ligaments do?They hold together the bones in movable joints.
32 8. What substance keeps bones from rubbing against each other? cartilage
33 9. What other functions does the skeletal system perform besides providing support and protection? Produces certain blood cellsStores minerals
34 10. Why are vertebrae important? The are the bones that make up your backbone, and all other bones are connected to the backbone.