Gas ExchangeGas Exchange

Miss JanMiss Jan

Gas exchange SLOsGas exchange SLOs

Be able to define gas exchangeBe able to define gas exchangeBe able to label and list the parts of Be able to label and list the parts of

the human breathing systemthe human breathing systemBe able to explain the breathing Be able to explain the breathing

processprocess

Respiration Breathing

Release of energy in the cells of the

body (needs OXYGEN)

Mechanical movement of body parts in

order to inhale and exhale air

(ventilation)

Inhale- exhaleInhale- exhale

Ribs move up and out

Diaphragm moves down

Ribs move down and in

Diaphragm moves up

From the front…From the front…

Lung capacity demo/practicalLung capacity demo/practical

Did you know…?Did you know…?The human lung can hold 6 litres of air.The human lung can hold 6 litres of air.

But only a small amount of air is moved But only a small amount of air is moved in and out of the lungs during breathing. in and out of the lungs during breathing. (500ml in normal breathing, 4.6 litres (500ml in normal breathing, 4.6 litres after inhaling forcefully, then breathing after inhaling forcefully, then breathing out completely)out completely)

The largest human lung capacity recorded is that of British rower Peter Reed (rower) at 11.68 litres. roughly twice that of an average person

Lung capacity depends on:Lung capacity depends on:

GenderGenderHeightHeightSmokingSmokingExerciseExercise

Pneumothorax: air trapped in the chest cavity.(Tension pneumothorax: life-threatening)

Pneumothorax: air trapped in the chest cavity.(Tension pneumothorax: life-threatening)

Gas exchangeGas exchange

GasInhaled air(air entering lungs)

Exhaled air(air leaving lungs)

Oxygen 21% 17%

Carbon dioxide

0.04% 4%

Nitrogen 78% 78%

The air we breath out have less oxygen and more carbon dioxide

It is important to distinguish between It is important to distinguish between 3 important terms:3 important terms:

Gas ExchangeGas Exchange = oxygen enters the body & = oxygen enters the body & carbon dioxide leaves.carbon dioxide leaves.

BreathingBreathing = a mechanical process that moves = a mechanical process that moves air in & out of the lungs.air in & out of the lungs.

RespirationRespiration is a biological process occurring in is a biological process occurring in all cells in the body where food & oxygen are all cells in the body where food & oxygen are taken in to release energy for the cell. taken in to release energy for the cell.

Be careful not to use the word respiration when Be careful not to use the word respiration when you mean breathing or gas exchange.you mean breathing or gas exchange.

Label diagram of human resp. sys.Label diagram of human resp. sys.

Alveoli (plural) Alveoli (plural) Alveolus (single)

Inflated

SurfactantSurfactant

Lipoprotein Lipoprotein produced by produced by alveolar cellsalveolar cells

Reduced surface Reduced surface tension tension (if no (if no surfactant – lung surfactant – lung cannot inflate cannot inflate normally)normally)

Gas exchangeGas exchange

WB page 12 - Read notes and create a flow WB page 12 - Read notes and create a flow diagram following the movement of air diagram following the movement of air from the atmosphere to the bloodstreamfrom the atmosphere to the bloodstream

AIR (outside)

Oral cavity

AIR (outside)

Oral cavity

Larynx (voice box)

Trachea (air pipe)Bronchi

Alveoli (air sacks)

Bloodstream

Capillary wall

Bronchiole

Surfactant

In the alveoli:In the alveoli:

- oxygen moves - oxygen moves ininto to the blood the blood

- carbon dioxide moves - carbon dioxide moves outout of the bloodof the blood

WB page 13: WB page 13:

Deoxygenated blood: Deoxygenated blood: blood with little blood with little oxygenoxygen

Oxygenated blood: Oxygenated blood: blood with lots of blood with lots of oxgyenoxgyen

NoseNose Air enters and leaves through – filters Air enters and leaves through – filters air for dust/bacteria using hairs & mucusair for dust/bacteria using hairs & mucus

larynxlarynx Voice box – may be used to make Voice box – may be used to make soundssounds

TracheaTracheaConnects the mouth and lungs, rings of Connects the mouth and lungs, rings of cartilage keep it open for efficient gas cartilage keep it open for efficient gas exchangeexchange

BronchiBronchi Where the trachea splits into two tubes Where the trachea splits into two tubes and enters the lungsand enters the lungs

alveolialveoliThin walled ‘bunches of balloons’ have Thin walled ‘bunches of balloons’ have a rich blood supply for easy gas a rich blood supply for easy gas exchangeexchange

6. Inhale – breathing in – muscles between the ribs contract pulling the ribs up and out. The diaphragm moves down and flattens out and this increases the volume of the chest

Exhaling – Breathing out – diaphragm relaxes and moves up, and ribs move down and in.

http://health.howstuffworks.com/adam-200020.htm