The Skeletal System

What is a bone?

The Skeletal system is made up of the bones and cartilage that forms the framework of your body.

Babies have 300 bonesAdults have 206 bones

The inside of a bone

The bone is made by salts, water and tissue.Inside the bone is the marrow, which produces blood cells.

Distal

epiphysi

s

Proximal

epiphysis

diaphysis

yellow

marrow

compact

bone

spongy bone

cartilage

Blood cell formation

Hematopoiesis (marrow)

SupportFramework that

supports body and cradles its soft organs

ProtectionFor delicate organs, heart, lungs, brain

MovementBones act as levers for

muscles

Mineral storageCalcium & phosphate

The Spine

The spine is the central support for the body.

The spina is made up of separate bones calles vertebrae.

Between each vertebrae is cartilage which keeps bone from rubbing against each other.

26 vertebrae in the human body!

Rib

Your rib is made up of 12 vertebrae.It protects your heart from knocks and bumps

Hands and feet

The bones in your hands and feet are VERY flexible.The foot has 26 bones.The hand has 27 bones.

Joints

Pivot

Hinge

GlindingBall-and-Socket Joint

Place where two

or more bones meet

Abduction

Extension

RotationFlexion

Adduction

Synovial Joint Movement

Diseases of the Skeletal System:

Osteoporosis- bone reabsorption outpaces bone deposit; bones become lighter and fracture easier

Factors: • age, gender (more in women)• estrogen and testosterone decrease• insufficient exercise (or too much)• diet poor in Ca++ and protein• abnormal vitamin D receptors• smoking

Osteoporosis

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Review (in pairs)

1. Describe 4 functions of bones.

2. Describe each type of joint

3. Describe two diseases that affect the skeletal system.

4. Red bone marrow produces blood cells. Children have red bone marrow in their long bones, while adults have yellow bone marrow, which stores fat. Why might adults and children have different kinds of marrow?

5. What might happen if children´s bones didn´t have growth plates of cartilage?