THe Skeletal System 1

Transcription

1 THe Skeletal System 1

2 What the Skeletal System DOes! Skeleton: works as the framework of your body and is made up of all of the bones in your body The number of bones in your skeleton depends on your age. a newborn has about 275 bones an adult has about 206 bones 2

3 5 functions of skeletal system The skeleton has 5 major functions: provides shape and support allows you to move protects your organs produces blood cells stores minerals and other nutrients (until your body needs them) 3

4 SHape and Support Your skeleton determines the shape of your body. The backbone, or vertebral column, is the center of the skeleton. all bones are connected to the vertebrae the vertebral column is made up of 26 vertebrae. 4

5 What are these bones that run down your back called? 5

6 Movement and Protection Your skeleton allows you to move because most of the bones in your body are associated with muscles. Muscles pull on the bones to make them move. Bones also protect many of the organs in your body. skull protects the brain breastbone and ribcage protect the heart and lungs 6

7 What organs are these bones protecting? 7

8 Production and Storage of Substances The long bones of your arms and legs make certain blood cells. Bones also store minerals. calcium phosphorus The bones release small amounts of minerals into the blood when the body needs them. 8

9 Joints of the Skeleton A joint is a place in the body where two bones come together. Joints allow bones to move in different ways. There are two types of joints: 1. immovable joints 2. movable joints 9

10 Immovable joints Immovable joints: connect bones in a way that allows little or no movement the bones of the skull are held together by immovable joints 10

11 Movable joints- allow the body to make a wide range of movements held together by ligaments (strong connective tissues) cartilage: connective tissue which is more flexible than bone cushions the ends of bones Street gymnasts link 11

12 movable joints - Where can they be found? 12

13 Types of Movable Joints Hinge Joint: allows forward or backward motion ex) knee and elbow 13

14 Types of Movable Joints Ball-and-socket Joint: allow the greatest range of motion ex) shoulders and hips 14

15 Types of Movable Joints Pivot Joint: allows one bone to rotate around the other ex) neck 15

16 Types of Movable Joints Gliding Joint: allows one bone to slide over another ex) wrist and ankle 16

17 What are the 4 types of movable joints? 1. Hinge joints 2. Ball-and-socket joint 3. Pivot joint 4. Gliding joint 17

18 BONES! Bones are complex living structures (organs) that undergo growth and development. 18

19 Bone Tissues Compact bone: hard and dense, but not solid small canals run through the compact bone the canals carry blood vessels and nerves from the bones surface to the living cells within the bone 19

20 Bone Tissues Spongy bone: located just inside the compact bone and at the ends of the bone has many small spaces within it spongy bone is lightweight and strong 20

21 Bone tissues Marrow: a soft, connective tissue in the spaces of bone Two types of marrow Red marrow: produces some of the body s blood cells Yellow marrow: stores fat that can serve as an energy reserve 21

22 Bone Strength The structure of bone makes it strong and lightweight. Bones are hard because they contain minerals (calcium and phosphorus). 22

23 Where do the minerals stored in your bones come from? You must eat them! 23

24 Bone Growth bones are alive-- they contain cells and tissues bones form new bone tissue as you grow Your bones absorb the force of your weight during physical activity. They respond by making new bone tissue. New bone tissue can also form after an accident. breaking a bone 24

25 Bones would not be very useful without muscles 25

26 muscles About 600 muscles in your body Found everywhere in your body Some muscles can be controlled by thinking about them; others can t 26

27 Categories of muscle Involuntary Voluntary 27

28 Involuntary muscles - muscles not under your conscious control Examples - muscles used in: heart beating breathing digesting food 28

29 voluntary muscles - muscles under your conscious control Examples - muscles used for: smiling picking up a book turning the page in a book standing 29

30 3 types of muscle tissue 1. Skeletal muscle 2. Smooth muscle 3. Cardiac muscle 30

31 Skeletal muscles - the muscles you think of first Characteristics: Voluntary muscles Attached to the bones of the skeleton Attached to bones by tendons React quickly Tire quickly Work in pairs 31

32 Smooth muscles Characteristics: Involuntary muscles found on the insides of many internal organs like the stomach and blood vessels React more slowly Tire more slowly 32

33 Cardiac muscles Characteristics: Involuntary muscles Found only in your heart Do NOT tire (thankfully!) 33

34 Skeletal muscles working in Pairs Muscle cells contract (become shorter, thicker) when nervous system tells them to. Muscle cells can only contract, not lengthen Work in pairs so that while one muscle contracts, the other relaxes to original length 34