4.1 Breathing

Question	Answer
What is the respiratory system?	The breathing system Takes air into and out of the body so that oxygen from the air can diffuse into the bloodstream and carbon dioxide can defuse out of the bloodstream into the air
Describe where the lungs are and how they are protected	Lungs in the upper part of the body (thorax) Protected by the ribcage Separated from the lower part of the body (abdomen) by the diaphragm
What happens when you inhale?	Intercostal muscles contract, pulling the ribcage upwards At the same time the diaphragm muscles contract, causing the diaphragm to flatten These two movements cause an increase in the volume of the thorax The consequent decrease in pressure to below that of the air surrounding the body results in atmospheric air entering the lungs
What happens when you exhale?	The intercostal muscles relax, allowing the ribcage to move downwards At the same time the diaphragm muscles relax, allowing the diaphragm to resume its domed shape These two movements cause a reduction in the volume of the thorax The consequent increase in pressure results in in air leaving the lungs
What do the alveoli provide?	A large surface area, richly supplied with blood capillaries, so that gases can readily diffuse into and out of the blood
Why might spontaneous breathing stop?	Disease Injury
What are the two main types of mechanical ventilator?	Negative pressure ventilators - cause air to be 'drawn' into the lungs Positive pressure ventilators - force air into the lungs

Resource summary

	Created by Anisha Rai about 8 years ago