B Y KA T H E R I N

E WA N G A

N D J EN N I F

E R CH E N G

The Skeletal System

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BACKGROUND provides support for the body protects the internal organs and fragile body tissues.  composed of all the bones in your body and other

tissues (tendons, ligaments, and cartilage) Has two parts, axial and appendicular

FUNCTIONS OF THE SKELETAL SYSTEM Strength: gives shape to body Protection of organs Leverage for movement Production of red blood cells

PARTS OF THE SKELETAL SYSTEM Axial skeleton

the main supportive structure of the body Central section of the skeleton Includes skull, vertebrae, sternum, and ribs

Appendicular skeleton Freely movable parts of upper and lower limbs Outer part of skeleton Includes shoulders, hip bones, arms, wrists, hands, legs, and feet

THE BONE Is responsible for shape and form of human body Made of cells and protein fibers surrounded by

calcium salts Stores important minerals such as calcium and

phosphorus Structure:

Outer layer of strong, dense, compact bone Under outer layer is spongy bone, which is lighter

than the top layer Most bones have bone marrow in the middle

Yellow marrow is made of fat cells and stores fat red marrow produces red and white blood cells and

platelets

GROWTH OF THE BONE Osteoclasts: cells that break down old bones and replace the old

bone with new bone tissue. This is called bone remodeling Chondroblasts: cells that are responsible for forming new cartilage When bones fracture, blood vessels in the bone also break. Blood clots and forms a fracture hemotoma, which keeps the bone

stable and stops the flow of blood Cells in the bone then remove dead and damaged tissue, which

causes swelling and inflammation After a few days, the fracture hematoma becomes tougher, and

turns into a soft callus Fibroblasts then start to produce collagen, a type of fiber and the

main protein in bones and connective tissues Osteoblasts then produce new bone cells

TYPES OF JOINTS Joints are the point of contact between two

bones Are classified by amount of movement

There are three types of joints Immovable Slightly movable Freely movable

Joints can also be known as an articulation

IMMOVABLE JOINTS Joints where two or more bones are located close together but

cannot move E. x.: The skull

Synarthrosis → The immovable joints between the bones of the skull

SLIGHTLY MOVABLE JOINTS Joints that are tightly connected but have limited movement

E. x.: back bone and hip bone

Back bone

FREELY MOVABLE JOINTSDo not have limited motion6 types of freely movable joints

Ball and socket joint → where the rounded head of a bone sits in the cup of another

o Is able to move in all directionsoE. x.: shoulder joint

Saddle joint → allows movement back and forth and side to side

oDoes not allow rotationoE. x.: the thumb

Hingle joint → where two bones open and close in a single direction

oE. x.: the knee joint

FREELY MOVABLE JOINTS (CONT.)

Pivot joint → where one bone swings around the ring formed by another boneoE. x.: elbow joint

Gliding joint → Also known as plane joint. Where one smooth surface slides across anotheroE. x.: wrist joint

Condyloid joint → allows movement without rotationoE. x.: jaw or finger joints

FREELY MOVABLE JOINTS (CONT.)

CONNECTIVE TISSUES AND PARTS Tendons: soft, elastic connective tissues that attach

muscle to bone Muscles move bones by pulling on tendons

Ligaments: tough tissue that connects bones to bones Cartilage: stiff but flexible tissue that is found between

joints Allows joints to move against each other without

pain Synovial membrane: a thin membrane in freely moving

joints that lines the joint capsule in fluid

WEAKNESSES/STRENGTHS OF THE SKELETAL SYSTEM

Bones can heal themselves Bones are very easily broken

6.8 million Americans fracture of break a bone each year

Most people in the U.S. will break two bones in his or her lifetime

TYPES OF FRACTURESOblique fracture: when a bone breaks diagonallyCommunited fracture: bone breaks into many piecesSpiral fracture: break occurs in a line around the boneCompound (open) fracture: broken bone sticks out of

the skinGreenstick fractures: bone breaks only on one side and

does not break completelyTransverse fracture: break occurs in a straight line

across the boneSimple fracture: bone is only partially fractured

DISEASES OF THE SKELETAL SYSTEM Osteoporosis: condition where your bones become weaker are likely to

break. treatment consists of eating calcium and vitamin D rich foods Medicine is also needed

Paget’s Disease of Bone: disease where bones grow weaker and larger than normal, making it easier to break your bones Symptoms are pain, enlarged or broken bones, and damage in the

cartilage Medicine and surgery is needed

Ewing’s Sarcoma: type of bone cancer in the bone marrow Symptoms include extreme pain and swelling at site of tumor Surgery, amputation, chemotherapy, and radiation are all used to cure it

HOW TO MAINTAIN HEALTH OF THE SKELETAL SYSTEM

Drink lots of milk: Milk contains a lot of calcium, which is good for your bones. Also take vitamin D and calcium supplements

Weight lifting exercises: weight lifting is essential to building strong bones and keep your bones healthy

Wear a helmet or other kinds of padding while playing sports. This prevents serious injury to bones

FUN FACTS Our bones would be 6 times stronger than

steel if both were the same weight The smallest bone is the same size of a rice

grain Of the 206 bones in the skeletal system, 52

of them make up our feet

Thank you!Any questions?