Functions of the Skeletal System: 1. Movement –Strong framework on which muscles can act 2. Supports & protects organs 3. Regulates and stores body minerals and fats –calcium, phosphorus 4. Produces red and white blood cells in bone marrow
Bone One of the hard parts forming the skeleton in vertebrate animals.
Bones are composed of tissue that may take one of two forms. Most bones contain both types. Compact- dense bone Spongy- cancellous bone
Compact bone- is dense, hard, and forms the protective exterior portion of all bones. Spongy bone- is inside the compact bone and is very porous (full of tiny holes) occurs in most bones.
Bone tissue The bone tissue is composed of several types of bone cells embedded in a web of inorganic salts (mostly calcium and phosphorus) to give the bone strength and collagenous fibers and ground substance to give the bone flexibility.
Bone marrow- the soft reddish substance inside the center of many bones that is involved in the production of blood cells and storage of fat.
Types of bone marrow Yellow marrow- yellow fatty tissue that fills the central cavities of long and stores fat in bones. In children, more red marrow fills the center of long bones. Red marrow- is the site of red and white blood cell production. It is found inside of long bones. This red marrow is replaced with yellow marrow as children become adults.
Food for thought Why do children have more red marrow in the center of their bones than adults?
Adult skeleton- –206 bones Newborn have more cartilage a.Bones start as cartilage b.Human babies contains more bones which begin to fuse together as the child grows.
No bones about it! The bones of the body fall into four general categories: 1.Long bones 2.Short bones 3.Flat bones 4.Irregular bones
Cartilage Lines the surface of joints so they move smoothly Cushions vertebrae Supports nose and ears
Movement Ligaments –Connects Bone to bone at a joint Prevents excessive movement Tendons –Connects muscle to muscle –Connects muscle to bone Play the air piano!!…what you see in your hands are your tendons working
Joints- A part of the body where bones are connected.
Care Nutrition: minerals –Calcium builds strong bones Found in dairy products During teen years, body builds most of its bone mass –Phosphorus Combines with calcium Milk, peas, beans, liver, cottage cheese, broccoli Exercise –Weight-bearing exercises increase bone mass –Promotes blood circulation which increases bone nourishment 99% of body calcium is in your bones!!!
Fractures Fracture: any type of break 2 types –Closed (aka simple) Nothing protrudes/sticks out –Open ( aka compound) One or both bone ends project through skin