Skeletal System

Let’s ask the experts

• What is the skeletal system?• http://www.brainpop.com/health/skeletals

ystem/skeleton/

X-Rays• Roentgen took the Fist X-Ray

picture

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.

Red marrow

Yellow marrow

Structure of bones

• http://www.brainpop.com/health/skeletalsystem/bonestructure/

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 cartilagea. Bones start as

cartilageb. 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 bones2. Short bones3. Flat bones4. Irregular bones

Four types of bones

Long Bones• Are longer than

they are wide• Work as levers• Upper and lower

extremities (examples- humerus, tibia, femur, ulna, metacarpals, etc.)

Short Bones–minimal or no shaft–Often square or cube shaped and found in the wrist and ankles.

Flat Bone• Skull• Two sheets of

compact bone• Spongy bone• They have broad

surfaces for protection of organs and attachment of muscles.

Irregular bones•Bones of the face and vertebrae

•They have varied shapes, sizes and surface features.

•All other bones that do not fall into the previous categories.

metacarpals

phalanges

(aka cranium)

scapula

metatarsalstarsals

phalanges

carpals

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.

• Ball and socket

• Hinge

• Pivot

Types of joints

• Gliding

• Cartlaginous

• http://www.brainpop.com/health/skeletalsystem/joints/

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