Gas Exchange Miss Jan

Gas exchange SLOs Be able to define gas exchange Be able to define gas exchange Be able to label and list the parts of the human breathing system Be able to label and list the parts of the human breathing system Be able to explain the breathing process Be able to explain the breathing process

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- exhale Ribs move up and out Diaphragm moves down Ribs move down and in Diaphragm moves up

From the front…

Lung capacity demo/practical

Did you know…? The human lung can hold 6 litres of air. But only a small amount of air is moved in and out of the lungs during breathing. (500ml in normal breathing, 4.6 litres after inhaling forcefully, then breathing out completely) The largest human lung capacity recorded is that of British rower Peter Reed (rower) at litres. roughly twice that of an average person

Lung capacity depends on: Gender Gender Height Height Smoking Smoking Exercise Exercise

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

Gas exchange

Gas Inhaled air (air entering lungs) Exhaled air (air leaving lungs) Oxygen21%17% Carbon dioxide 0.04%4% Nitrogen78% The air we breath out have less oxygen and more carbon dioxide

It is important to distinguish between 3 important terms: Gas Exchange = oxygen enters the body & carbon dioxide leaves. Gas Exchange = oxygen enters the body & carbon dioxide leaves. Breathing = a mechanical process that moves air in & out of the lungs. Breathing = a mechanical process that moves air in & out of the lungs. Respiration is a biological process occurring in all cells in the body where food & oxygen are taken in to release energy for the cell. Respiration is a biological process occurring in all cells in the body where food & oxygen are taken in to release energy for the cell. Be careful not to use the word respiration when you mean breathing or gas exchange.

Label diagram of human resp. sys.

Alveoli (plural) Alveolus (single)

Inflated

Surfactant Lipoprotein produced by alveolar cells Lipoprotein produced by alveolar cells Reduced surface tension (if no surfactant – lung cannot inflate normally) Reduced surface tension (if no surfactant – lung cannot inflate normally)

Gas exchange WB page 12 - Read notes and create a flow diagram following the movement of air from 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: - oxygen moves into the blood - carbon dioxide moves out of the blood WB page 13: Deoxygenated blood: blood with little oxygen Oxygenated blood: blood with lots of oxgyen

Nose Air enters and leaves through – filters air for dust/bacteria using hairs & mucus larynx Voice box – may be used to make sounds Trachea Connects the mouth and lungs, rings of cartilage keep it open for efficient gas exchange Bronchi Where the trachea splits into two tubes and enters the lungs alveoli Thin walled ‘bunches of balloons’ have a rich blood supply for easy gas exchange

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 htm