Biology

Skeletal SystemLearning Objectives

To be able to name and locate important bones in the skeletal system

To know the functions of the skeletal system

To be able to explain what makes bones strong

Skull

Clavicle

Humerus

Radius

Femur

Fibula

Tibia

Ulna

Vertebral Column

Rib Cage

Sternum

(Collar bone)

(Spine)

(Breast bone)

(Shin bone)

To be able to name and locate important bones in the skeletal system

5 main functions of the skeletal system are:

Support – Give your body shape and provide a supporting framework.

Protection – protect vital organs. Cranium protects your brain; Thorax protects heart and lungs; Vertebral Column protects spinal cord.

Attachment for Skeletal Muscle – parts of the skeleton provide a surface for your muscles to attach too. Tendons attach muscle to bone – levers – provides movement.

Blood Cell Production - Stored within your long bones is Marrow. Bone Marrow is continually producing Red and White blood cells.Essential function – as a large number of RBC die every minute.

Store of Minerals – Supply of minerals such as Calcium and Phosphorus. Essential for bone growth and maintenance. Released into the bloodstream as and when the body needs them.

Match what do these bones protect?

Skull

Sternum

Rib Cage

Vertebral Column

Clavicle

Brain

Heart and lungs

Heart and lungs

Spinal cord

Nerve bundle

To know the functions of the skeletal system

To be able to explain what makes bones strong

At what age does half of our skeletal mass develop?

What vitamins and minerals are important for strong bones?

How much time is recommended to be out in the sun each week?

What food or drink is important in making bones strong?

What can help protect strong bones?

Between 11 - 20

Calcium and Vitamin D

5 to 15 minutes - we get vitamin D from the sun

Milk - has calcium and vitamin D

Exercise - like walking and running

Joints

Ligaments hold bones together but are flexible enough to let them move.

Cartilage absorbs forces to stop bones smashing into each other, and fluid reduces friction to stop them wearing away.

Joints permit bodily movement and are held together by fibres called "ligaments".

Some joints, like those in the skull, allow no movement.

Others may permit only limited movement: for example the joints in the spine allow some movement in several directions.

Moveable joints are continuously lubricated to prevent friction. These joints have a variable range of movement, and these are called "synovial" joints.

Joints are sturdy enough to hold the skeleton together while permitting a range of motions.

Joints are lubricated by "synovial" fluid. The ends of these joints are coated with

articular (or hyaline) cartilage, which reduces friction and cushions against jolts.

Between the bones, in a narrow space, is the joint "cavity," which gives us freedom of movement.

Ligaments then bind these bones to prevent dislocations and limit the joint's movements.

The greatest range of joint movement is provided by a "ball-and- socket" joint, in which the spherical head of one bone lodges in the spherical cavity of another

                 

The simplest type of joint is the "hinge," as found in the elbows and the joints of the fingers and toes.

Hinge joints allow movement in only one direction.

               

Elbow

A pivot joint allows two bones to move in a rotational motion by twisting against each other

The radio-ulnar joint in the elbow, or atlas/axis in the neck do this

Bones at the knee joint are lined with ….. at the surfaces which move against each other. This ….. is very tough and ….., which reduces friction.

Additionally, the synovial fluid acts like oil on a bike wheel, and also reduces …. This stops the bone from ….. away. The joint is held together by elastic ….. so that it is strong but flexible.

Crossing the joint are ……. They ….. muscle to bone. When a muscle contracts it is able to pull on a bone. Without a tendon, no ….. force would reach a bone!

ligaments pull cartilage frictionsmooth wearing tendons attach

Muscles are moved whenever you move.Without them, we wouldn’t be able to move.

How many muscles do you think there are your body?

Over 650! They make up nearly half of your body weight.

1) Skeletal– Only Voluntary muscles in

your bodyStriated or stripe like

markings.Surrounds the skeleton and

gives the body the ability to move.

Skeletal muscle Cardiac muscle Smooth muscle

2) Cardiac – Muscle of the Heart.Striated like skeletalNot under conscious control –

Involuntary muscle

3) Smooth – Located in the walls of the

intestines, blood vessels, stomach

and urinary bladderNot under conscious control –

Involuntary muscle. Non – striated.

Other contracting muscles are automatic.

Can you think of any examples? Contracting of your heart the movement of your diaphragm so

that you can breathe blinking your eyes are automatic.

Some muscles are known as "voluntary" -- that is, they only work when you specifically tell them to.

Can you think of some voluntary movements?

Clap you hands, lift your leg, arm

Hold a 1kg mass in your palm and rest your right forearm on the bench.Grab the flesh on your upper arm and slowly lift and lower the mass.How does your muscle change?

The muscle you used was your biceps?

When your biceps contracts, your arm bones pull together and your hand swings upwards.

Lift the 1kg mass again. This time, feel inside your elbow as you lift.What can you feel?

The strong cord is a tendon.

It attaches your muscle to your bone.

TendonsHold one wrist tightly while you wiggle your fingers. What do you notice?

Did you feel tendons moving just below your skin?

Your largest tendon joins your calf muscle to your heel bone.

Pairs of muscles that create movement.

The muscle that relaxes or lengthens during the movement is called the Antagonist.

If you take part in lots of exercise what will happen to your muscles?

They will get bigger and stronger

You have over 30 facial muscles which create looks like surprise, happiness, sadness, and frowning.

Eye muscles are the busiest muscles in the body. Scientists estimate they may move more than 100,000 times a day!