BONES AND MUSCLES © copyright 2014 All Rights Reserved CPalms.org 2.BONES The framework of the human body is composed of 206 bones and it forms the skeletal system. This system has 5 major functions. The skeleton gives shape and support to your body. Bones protect your internal organs. Major muscles are attached to bone and help them move. Blood cells are formed in the center of the soft tissue called marrow. Finally, major quantities of calcium and phosphorous compound, which make bones hard, are stored in the skeleton. © copyright 2014 All Rights Reserved CPalms.org 3. BONE FORMATION Osteoclasts are cells that break down these specialized organs. Osteoblasts are cells that form these specialized organs. © copyright 2014 All Rights Reserved CPalms.org 4.PERIOSTEUM Periosteum: a living bone’s surface is covered with this tough tight fitting membrane. Blood vessels contained within carry nutrients to the bone. Cells involved in the growth and repair of bones are also found in the periosteum. There are two types of bones under the periosteum, spongy and compact. © copyright 2014 All Rights Reserved CPalms.org 5.COMPACT AND SPONGY BONE Compact Bone: This is located directly under the periosteum. Calcium and phosphate components make compact strong. Bone cells and blood vessels are found in this layer. Compact bone is arranged in circular structures called the Haversian system. This system consists of tiny connected channels through which blood vessels and nerve fibers pass. Spongy Bone: Spongy bone is located towards the end of long bones like your thigh and upper arm. Spongy bone has many small open spaces that make the bones lightweight. In the center of long bones are large opening called cavities. These cavities and spaces in spongy bone are filled with marrow. Some marrow is yellow and is made f fat cells. Red marrow produces red blood cells at a rate of 2-3 million per second. © copyright 2014 All Rights Reserved CPalms.org 6. CARTILAGE Cartilage: cartilage is the smooth slippery thick layer of tissue what covers the ends of bones. There are no blood vessels or minerals contained in cartilage. Nutrients are delivered by nearby blood vessels. Because cartilage is flexible acts like a shock absorber for the joints. It also reduces friction caused by bones rubbing together. © copyright 2014 All Rights Reserved CPalms.org 7. JOINTS AND LIGAMENTS Joint: A place where two or more bones come together. Ligament: This is a tough band of tissue that holds the bones together at the joints. © copyright 2014 All Rights Reserved CPalms.org 8. MOVABLE AND IMMOVABLE JOINTS Immovable joints: These are joints that allow little or no movement. The skull and pelvis are examples. Movable joints: These allow the body to move in a wide range of motions. There are 4 types of moveable joints: pivot, ball and socket, hinge and gliding. © copyright 2014 All Rights Reserved CPalms.org 9. MOVABLE JOINTS Ball and Socket: This a ball with a rounded end that fits in the cavity of another bone. Swinging arms and legs in any direction is an example of this motion. Hinge: This joint has a smaller range and has a back and forth motion like a door. These joints are found in elbows, knees and fingers. Gliding: This joint is where one part of the bone slides over another and they also move back and forth. They are found in wrists ankles and in between vertebrae Pivot: One bone rotates in a ring of another bone that does not move. Turning your head is an example. © copyright 2014 All Rights Reserved CPalms.org 10. MUSCLES 9.MUSCLES There are 600 muscles in the muscular system. Muscles connect some of the bones in your body. A muscle is an organ that can relax, contract and provide the force to move a body. As a result energy is used and work is done. © copyright 2014 All Rights Reserved CPalms.org 11. VOLUNTARY AND INVOLUNTARY MUSCLES Involuntary muscles: These are muscles that cannot be consciously controlled. This is how blood is pumped and food is digested. Voluntary muscles: These are muscles that can be consciously controlled. © copyright 2014 All Rights Reserved CPalms.org 12. MUSCLE TYPES Skeletal muscles: these are muscles that move bones. Cardiac muscle: These type of muscles are found only in the heart. The cardiac muscle is striated and it contracts about 70 times per minute every day all day. Smooth muscle: These muscles are found in the intestines, bladder, blood vessels and other internal organs. They are non-striated and they contract and relax slowly. © copyright 2014 All Rights Reserved CPalms.org 13. WORKING MUSCLES AND TENDONS Working muscles: When one muscle in a pair contracts the other relaxes. Chemical energy is used in this process. Tendons: These are thick bands of tissues that connect skeletal muscles to bones. © copyright 2014 All Rights Reserved CPalms.org 14. HOW MUSCLES MOVE How do muscles and bones work together to produce movement? When the muscles contract they pull on the bones they are attached to, to create movement. The muscles action of pulling on the bones helps them move in all different directions. We need muscles to move involuntary and voluntary. Muscles create 85% of body heat, and hold our posture. The brain sends impulses to the muscles to move bones, which is movement. One needs the other to work. Together they produce bodily movement. When the brain sends impulses to the muscles, it causes them to contract and because they are connected to the bones the bones are moved along with the muscles. Muscles receive messages from brain through the somatic nervous system telling the muscles to move. Muscles listen and contract then the bone is pulled along with the muscle by the tendon. The bone is there to support the body. © copyright 2014 All Rights Reserved CPalms.org 15. LEVERS There are 3 types of levers in this body system called 1st , 2nd and 3rd class. © copyright 2014 All Rights Reserved CPalms.org THE END © copyright 2014 All Rights Reserved CPalms.org