THE SKELETAL SYSTEM OVERVIEW The skeletal is one of the most important systems in the human body. Without it, the shape of your body would change, and you would not be able to stand up straight and move around with ease. Therefore, it is important to eat the right kind of food and to exercise regularly to keep your skeletal system strong and healthy. You should also take care of your own safety when carrying out daily activities to avoid injury to the skeletal system and to rest of the body. WHAT MAKES UP THE SKELETAL SYSTEM WHAT ARE THE FUNCTIONS OF THE SKELETAL SYSTEM? The Skeletal system: ⮚ protects your internal organs ⮚ produces blood cells ⮚ supports and gives shape to your body ⮚ facilitates movement with the help of muscles ⮚ stores minerals such as calcium and phosphorus HOW MANY BONES ARE THERE IN THE SKELETAL SYSTEM Part of the skeletal system number of bones ⮚ Skull and upper jaw 21 ⮚ Each ear has 3 tiny bones 6 ⮚ Lower jaw (mandible) 1 ⮚ Front neck bone (hyoid) 1 ⮚ Backbone or spine 26 ⮚ Ribs (12 pairs) 24 ⮚ Breastbone 1 ⮚ Each upper limb has 32 bones: 2 in shoulders, 2 in arm, 8 in wrist, 19 in hand and finger 64 ⮚ Each lower limb has 31 bones: 1 in hip, 4 in ankle, 19 in foot and toes 62 Total = 206 bones There are altogether 206 bones in the skeletal system. WHAT ARE THE DIFFERENT TYPES OF BONES IN THE SKELETAL SYSTEM There are four different types of bones found in the skeletal system. They are the: ⮚ Long bones ⮚ Short bones ⮚ Flat bones ⮚ Irregular-shaped bones LONG BONES Most of the bones in the arms and legs are long bones. The long bones found in the skeletal system are: ⮚ Clavicle ⮚ Radius ⮚Metacarpals ⮚ Femur ⮚ Fibula ⮚ Humerus ⮚ Ulna ⮚ Phalanges ⮚tibia ⮚ Metatarsals WHAT DOES THE INSIDE OF A LONG BONE LOOK LIKE Long bones have a thick external layer of compact bone. Inside the shaft is the medullary cavity filled with bone marrow which produced blood cells. The ends of a long are made of spongy bone. The anatomy of long bone SHORT BONES Short bones contain mostly spongy bone with a thin layer of compact bone on the outer surface. The short bones found in the skeletal system are: ⮚ Tarsals ⮚ Carpals ⮚ Patellas IMAGE OF SHORT BONES FLAT BONES Flat bones are made up of a layer of spongy bone between two thin layers of compact bone. Flat bones are thin and have broad surfaces. The flat bones found in the skeletal system are: ⮚ Cranium ⮚ Sternum ⮚ Ribs ⮚ Pelvis ⮚ Scapula IMAGE OF FLAT BONES IRREGULAR – SHAPED BONES These bones have several projections on them that make them irregular in shaped. The irregular – shaped bones found in the body include all bones in the spinal column. IMAGE OF AN IRREGULAR – SHAPED BONES WHAT ARE JOINTS Joints are the areas where bones meet. Three different types of joints are: ⮚ Fixed joints ⮚ Slightly movable joints ⮚ Synovial or freely movable joints FIXED JOINTS In a fixed joints, one bone is connected directly to another bone. Under normal conditions, these joints are not movable. Fixed joints can be found in the skull and pelvis. SLIGHTLY MOVABLE JOINTS The bones of these joints are separated by a layer of cartilage. Joints in the spine and ribs are slightly movable and have a limited range of movement. SYNOVIAL OR FREELY MOVABLE JOINTS The area between the bones of a synovial joint is filled with synovial fluid, which helps to lubricate and protect the cartilage-covered ends of the bones. These bones are held together by ligaments, which are strong stretchy bands of fibrous tissue. A synovial joint allows for much more movement than other joints. SIX TYPES OF MOVABLE JOINTS ⮚ Ball and socket joint ⮚ Hinge joint ⮚ gliding joint ⮚ pivot joint ⮚saddle joint ⮚ condyloid joint BALL AND SOCKET JOINT A ball and socket joint can be moved in almost any direction. It is found in the hips and shoulders. HINGE JOINT A hinge allows for extension and flexion. Elbow and knees are examples of hinge joints. GLIDING JOINT In a gliding joints, the bones slide past each other. Metacarpals (wrist) and metatarsals (ankle) are gliding joints. PIVOT JOINT A pivot joint can be rotated around an axis. The neck and forearms have pivot joints. SADDLE JOINT A saddle joint can be moved up and down as well as back and forth but cannot be rotated like a ball and socket joint. The thumb is an example of a saddle joint. CONDYLOID JOINT A condyloid joint can be moved up and down as well as sideways. An example of a condyloid joint is the wrist joint. DISEASES AND DISORDERS OF THE SKELETAL SYSTEM Sprain A sprain is an injury to a ligament or to the tissue that covers a joint. Most sprains occur when the bones of a joint are twisted forcefully in a direction in which they would usually not move or further than they should moved. Twisting your ankle is the most common sprain and can be very painful. Swelling and discolouration of the joint are signs of a sprain. If the sprain is severe, you should seek medical attention but it is fairly minor, you can treat it yourself by using the ‘RICE’ method for treating sprains. FOLLOWS THESE STEPS: R: REST the affected joint. This means that you should not move the affected joint around a lot; limit your use of the joint to allow it to heal. I: ICE the affected joint. Use ice on the affected joint as soon as possible after the sprain. This will help to reduce swelling and speed up the healing process. C: COMPRESS the affected joint. Compressing the joints also helps to reduce swelling, besides giving support to the joint. You do this by wrapping the joint with bandage. E: ELEVATE the affected joint. Elevating allows the blood to flowback to the heart instead of pooling at the affected joint, thereby further reducing swelling. FRACTURE A fracture is a broken bone. The diagrams below show some common kinds of fractures. All fractured bones should be immobilised and medical attention should be sought as soon as possible. SCOLIOSIS AND KYPHOSIS Scoliosis is a sideways curve of the spine. This affects the posture, causing difficulty in standing straight. Kyphosis is forward bending of the spine; the person appears to be leaning forward. Both scoliosis and kyphosis should be treated by a doctor. In most cases, a brace is used to try to straighten the spine.
