Skeletal System Notes

Your body has two organ

systems that work together to

provide support & help you move–

the skeletal system & the

muscular system.

The skeletal system is made up of bones & cartilage that for the framework of your body.

The muscular system includes the muscles that help you move & help things inside your body move.

All humans have a stiff internal skeleton made of bone.

The bones of your

body have five main

jobs–

-to support the body & give it shape

-to protect internal organs

-to work with the muscles to move

-to store fat & other minerals (calcium & phosphorus)

-to make blood cells (bone marrow)

A human baby is born with 350 bones, but an adult human has 206 bones.

Bones are made up of mostly calcium & phosphorus.

Bones are very much alive & contain blood

vessels & nerve tissue.

Cartilage is a strong flexible

connective tissue found at end of

bones where they act as a cushion.

Cartilage has no blood cells so it

must absorb nutrients from

body fluids. (diffusion)

Bones are attached to other bones

by connective tissues called

ligaments.

A joint is the place where two bones come together & are joined by ligaments to allow bones to move in different ways.

Two types of joints in

the body…

Immovable joints allow little or no movement (skull & ribs)

Movable joints that allow a

wide range of movement.

Pivot joint•Bones rotate

around each other (allows side-to-

side motion)

Examples…Neck

Gliding joint•Bones slide

over each other (allows you to bend & flex)

Examples…Wrist, ankle, Wrist, ankle, vertebrae (back)vertebrae (back)

Hinge jointBack-and-forth motion (can only

move one direction…

unable to twist)

Examples…Knee, elbow, Knee, elbow, fingers, toes, jawfingers, toes, jaw

Ball & socket joint

Rotational or circular motion… greatest range

of motion

Examples…Shoulder, hip

The best way to keep your bone healthy are regular exercise & to eat a balanced diet with meats, beans, green leafy vegetables & dairy products.

Osteoporosis is the condition where mineral loss causes bones to become weak & break easily.

Arthritis is pain,

stiffness or swelling in the joints.

Cranium

Pelvis