Skeletal System

BONES, BONES, BONESChapter 1 Section 1

Bones are living tissues, made of

cells.They take in nutrients and use energy.

They are ALIVE!

Made up of all the bones in your body.

Skeletal System

Functions Of Skeletal SystemGive body shape and support

Protect your internal organs

They serves as an attachment point for muscles, helping them to move.

Blood cells are made in the centre of bones

Calcium and phosphorous compounds are stored in bones for later use. They also make bones hard.

Bone Structure

•Bones are not smooth.

•They have bumps, edges, round ends, rough spots, and many pits and holes.

Bones Structure

Why the bumps and holes?

•Muscles and ligaments attach to the bumps and pits.

•Blood vessels and nerves enter and leave through the holes.

PeriosteumSurface of bone is covered with a tough, tight-fitting membrane

Periosteum

Small blood vessels in periosteum carry nutrients into the bone

Cells for growth and repair of bone are found here also

Under the periosteum are two types of bone - compact bone and spongy bone

Compact BoneDirectly under the periosteum.

Compact bone is hard and strong.

Gives bones strength.

Contains calcium and phosphate.

Contains bone cells and blood vessels

It is living. It is keeps bones from being too rigid, brittle or easily broken

Spongy BonesLocated at the ends of your long bones, like our

thigh and upper arm bone.

Have many small openings to keep the bone lightweight

The centers of long bones have a large opening called a cavity.

These cavities are filled with marrow.

Marrow is also in openings of the spongy bone

Spongy Bone

MARROWYellow marrow contains fat cells

Red marrow produces red blood cells

How long does it take to produce 2-3 million red blood cells?

1 Second

CartilageThe ends of bones are covered with a smooth,

slippery, thick layer of tissue called cartilage

Cartilage does not contain blood vessels or minerals

Flexible

Absorbs shocks in joints

Makes movement easier, reduces friction

Can be damaged

No Bones Here

Bone FormationBeginning skeleton was made of cartilage.

It gradually broke down and was replaced by bone.

Osteoblasts (bone forming cells) deposited minerals calcium and phosphorus in the bones, making the bone tissue hard.

At birth you had 300 bones. You now have 206 bones.

How did you lose 94 bones??

Some fused, or grew together.

No Bones Here

Osteoblasts build up bone.

Osteoclasts….

…break down bone tissue.

This is normal and healthy.

Osteoclasts release calcium and phosphorus into the blood stream, which are needed to keep your body working properly, including moving your muscles.

JointsAny place where two or more bones come

together

The bones are separated by cartilage and are held together by ligaments

Immovable Joints

Examples: Skull, Pelvis

Pivot Joints

Examples: arm, head

Ball and Socket

Examples: Hip, Shoulder

Hinge Joint

Exampleselbows,

knees, fingers

Gliding Joint

Exampleswrists, ankles

vertebrae

Joint Problems?