Body In Action Body In Action

RevisionRevision

MovementMovement

The skeleton is required for:The skeleton is required for:

Muscle attachmentMuscle attachmentSupportSupportProtectionProtection

Ribs Ribs Heart & Lungs Heart & LungsSkull Skull Brain BrainVertebrae Vertebrae Spinal Cord Spinal Cord

Bone is made up of:Bone is made up of:

Hard minerals – Calcium phosphateHard minerals – Calcium phosphate

Flexible fibres – living bone cellsFlexible fibres – living bone cells

Joints can be:Joints can be:

Ball & Socket Ball & Socket Hip / shoulderHip / shoulderAllows movement in 3 planesAllows movement in 3 planes

Hinge Hinge Knee / ElbowKnee / ElbowAllows movement in 1 planeAllows movement in 1 plane

Synovial Joints - CreditSynovial Joints - Credit

Freely movable jointsFreely movable joints

StructureStructure FunctionFunction

LigamentLigament Holds BONES togetherHolds BONES together

CartilageCartilage Reduces friction & acts Reduces friction & acts as a shock absorberas a shock absorber

Synovial MembraneSynovial Membrane Secretes synovial fluidSecretes synovial fluid

Synovial FluidSynovial Fluid Lubricant which reduces Lubricant which reduces friction.friction.

Muscles & MovementMuscles & Movement

Muscles bring about movement Muscles bring about movement in the body.in the body.

Muscles can only contract or Muscles can only contract or relax – they cannot make relax – they cannot make themselves longer.themselves longer.

MusclesMuscles

Muscles are attached to bones by Muscles are attached to bones by inelastic tendonsinelastic tendons

They must be inelastic so that when a muscle They must be inelastic so that when a muscle contracts they pull on the bone!!contracts they pull on the bone!!

Antagonistic Pairs - CreditAntagonistic Pairs - Credit

Muscles must work in pairs.Muscles must work in pairs.

When one muscle contracts the other When one muscle contracts the other relaxes allowing the joint to move.relaxes allowing the joint to move.

To straighten the joint the opposite To straighten the joint the opposite muscles contract and relax.muscles contract and relax.

The Need for EnergyThe Need for Energy

Energy In FoodEnergy In FoodEnergy in food is measured in Energy in food is measured in

KILOJOULES.KILOJOULES.

The amount of energy required by a The amount of energy required by a person depends onperson depends onSizeSize AgeAgeSexSex Activity levelsActivity levels

Weight LossWeight Loss Weight GainWeight Gain Energy ImbalanceEnergy Imbalance

Comparing Inhaled & Exhaled AirComparing Inhaled & Exhaled Air

Inhaled AirInhaled Air High OxygenHigh Oxygen Low Carbon DioxideLow Carbon Dioxide

Exhaled AirExhaled Air Low OxygenLow Oxygen High Carbon DioxideHigh Carbon Dioxide

During Aerobic Respiration oxygen is used up During Aerobic Respiration oxygen is used up and carbon dioxide is produced.and carbon dioxide is produced.

The Respiratory SystemThe Respiratory System

The trachea ( windpipe) is supported by The trachea ( windpipe) is supported by rings of cartilage.rings of cartilage.

Mucus catches dirt & bacteria and is Mucus catches dirt & bacteria and is carried to the top of the trachea by cilia.carried to the top of the trachea by cilia.

The mucus is then swallowed.The mucus is then swallowed.

BreathingBreathing

Breathing is brought about by the muscles Breathing is brought about by the muscles of the ribs (intercostal muscles) and the of the ribs (intercostal muscles) and the diaphram contracting & relaxing.diaphram contracting & relaxing.

During inspiration the volume of the chest During inspiration the volume of the chest cavity increases and air rushes in to fill the cavity increases and air rushes in to fill the space.space.

During expiration the volume of the chest During expiration the volume of the chest decreases and air is pushed out.decreases and air is pushed out.

Gas ExchangeGas Exchange

Gas exchange takes place in the alveoli Gas exchange takes place in the alveoli (air sacs)(air sacs)

To allow effiecient gas exchange the To allow effiecient gas exchange the alveoli have a:alveoli have a:Large surface areaLarge surface areaMoist surfaceMoist surfaceGood blood supplyGood blood supplyThin liningThin lining

The Circulatory SystemThe Circulatory System

The heart is a muscular pump The heart is a muscular pump Pumps blood around the body Pumps blood around the body Supplies all cells with Supplies all cells with

Food Food Oxygen Oxygen

Removes wastesRemoves wastesCarbon dioxideCarbon dioxide

Structure of the heartStructure of the heart

The muscle of the left side is much thicker as it must pump blood all around the body.

The muscle on the right side is thinner. It only pumps blood to the lungs

Valves preventthe backflowof blood

The Circulatory System – Blood The Circulatory System – Blood FlowFlow

Blood VesselsBlood Vessels Arteries

thick, muscular walls carry high pressure blood away

from the heart

Veins thin, stretchy, muscular walls return low pressure blood to the

heart Valves prevent backflow of blood

Capillaries tiny blood vessels connect arteries and veins carry blood to the cells of the body

The Coronary ArteryThe Coronary Artery

Leads from the aorta - supplies blood to Leads from the aorta - supplies blood to heart muscle.heart muscle.

Blockage can result in a heart attackBlockage can result in a heart attack

The BloodThe Blood Blood is made up of:Blood is made up of:

Plasma – liquid which carries Plasma – liquid which carries cells and dissolved substancescells and dissolved substances

Red blood cells – carry oxygenRed blood cells – carry oxygen

White blood cells – fight White blood cells – fight infectioninfection

Platelets – help clot bloodPlatelets – help clot blood

Gas ExchangeGas Exchange

As blood flows through capillaries oxygen As blood flows through capillaries oxygen diffuses from the blood into the cells.diffuses from the blood into the cells.

Carbon dioxide from the cells diffuses into Carbon dioxide from the cells diffuses into the blood and is carried away.the blood and is carried away.

Blood high in oxygen Blood high in carbon

dioxide.

Capillary NetworksCapillary Networks

To allow efficient gas exchange the To allow efficient gas exchange the capillary network has:capillary network has:A large surface areaA large surface areaVery thin cell wallsVery thin cell walls

HaemoglobinHaemoglobin

Red blood cells contain haemoglobin.Red blood cells contain haemoglobin.This combines with oxygen in the lungs to This combines with oxygen in the lungs to

form oxyhaemoglobin.form oxyhaemoglobin.

As the blood passes through cells which As the blood passes through cells which have low oxygen levels the have low oxygen levels the oxyhaemoglobin releases the oxygen oxyhaemoglobin releases the oxygen which can then be used by the cells.which can then be used by the cells.

CoordinationCoordination

The EyeThe Eye

The structure of the eye:The structure of the eye:

CorneaCornea - focusing of light. - focusing of light. LensLens - fine focuses the light onto the - fine focuses the light onto the retinaretina IrisIris - controls the size of the - controls the size of the pupil, pupil, controling the controling the

amount of light entering the eye.  amount of light entering the eye.  RetinaRetina - layer of light sensitive cells where an - layer of light sensitive cells where an

image is formed.image is formed. OpticOptic nervenerve - carries the nerve impulses to the - carries the nerve impulses to the

brain. brain. Blind spotBlind spot – where the optic nerve meets the – where the optic nerve meets the

retina – no image is formed here.retina – no image is formed here.

Binocular VisionBinocular Vision

Using two eyes allows us to judge Using two eyes allows us to judge distance.distance.

This is called binocular vision.This is called binocular vision.

The EarThe Ear

Judging DirectionJudging Direction

Using two ears allows us to judge the Using two ears allows us to judge the direction of sound more effectively.direction of sound more effectively.

BalanceBalance

The position of the head can be judged by The position of the head can be judged by the position of fluid in the semi – circular the position of fluid in the semi – circular canals.canals.

The Nervous SystemThe Nervous System

The human nervous system is made up of The human nervous system is made up of

The brainThe brainThe spinal cordThe spinal cordThe nervesThe nerves

The brain & spinal cord The brain & spinal cord make up the central make up the central nervous system (CNS).nervous system (CNS).

Functions of parts of the brainFunctions of parts of the brain

Cerebrum – conscious Cerebrum – conscious thought, memory, senses, thought, memory, senses, intelligence, imagination.intelligence, imagination.

Cerebellum – balance & Cerebellum – balance & coordination.coordination.

Medulla (brain stem) – Medulla (brain stem) – breathing & heart rate.breathing & heart rate.

NervesNerves

Sensory Neurons carry information from sense Sensory Neurons carry information from sense organs to the brain.organs to the brain.

Information is decoded in the brain.Information is decoded in the brain. Motor Neurons carry information back to the Motor Neurons carry information back to the

body.body.

Reflex ReactionsReflex Reactions

Very quick.Very quick.

Protect the body from harm.Protect the body from harm.

Do not involve conscious thought.Do not involve conscious thought.SneezingSneezingBlinkingBlinkingLimb withdrawal (eg from heat)Limb withdrawal (eg from heat)

The Reflex ArcThe Reflex Arc

Relay nerves in the spinal cord send information from the sensory neurone straight to the motor neurone

Changing Levels of Changing Levels of PerformancePerformance

Muscle FatigueMuscle Fatigue

Muscle fatigue occurs due to the build up Muscle fatigue occurs due to the build up of lactic acid in muscles that are of lactic acid in muscles that are exercising.exercising.

Lack of oxygen results in anaerobic Lack of oxygen results in anaerobic respiraton which causes lactic acid to respiraton which causes lactic acid to form.form.

Anaerobic RespirationAnaerobic Respiration

Only a little energy is released.Only a little energy is released.

During rest oxygen is needed to remove During rest oxygen is needed to remove the lactic acid formed.the lactic acid formed.

This is known as the ‘oxygen debt’.This is known as the ‘oxygen debt’.

ExerciseExercise

Exercise causes the heart rate & Exercise causes the heart rate & breathing rate to increase.breathing rate to increase.Allows more blood carrying sugar & Allows more blood carrying sugar &

oxygen to be supplied to muscles.oxygen to be supplied to muscles.

The time taken for these to The time taken for these to return to normal following return to normal following exercise is the RECOVERY exercise is the RECOVERY TIME.TIME.

Fitter people have a shorter recovery time Fitter people have a shorter recovery time than unfit people.than unfit people.

They also have lower levels of lactic acid They also have lower levels of lactic acid production.production.

Recovery time can be improved by regular Recovery time can be improved by regular exerciseexercise