Year 8 Science | Breathing and Health Flashcards
What is breathing?
Muscles changing the size of your lungs to bring air in and out
What is ventilation?
Air moving in and out of the lungs
What two structures change the pressure inside the chest cavity to ventilate lungs?
Muscles between the ribs (intercostal) + Diaphragm
What does the diaphragm do when we breathe in?
Contracts and moves down
What does the state of the diaphragm do when we breathe out?
Relaxes and returns to dome shape
Why does moving the diaphragm down cause air to enter the lungs?
The volume increases, so the pressure drops so air is drawn in
What affects how fast we breathe?
How much oxygen we need - the more we are moving the more we need e.g. running
What is the scientific name for the windpipe?
Trachea
What does the trachea divide into?
Two bronchi
Outline the flow of air from the atmosphere into our lungs, starting from the nasal cavity.
Nasal cavity –> trachea –> bronchi –> bronchioles –> alveoli
We breathe in (inhale) to take in…..
oxygen
We breath out (exhale) to remove….
carbon dioxide
What do we need oxygen for?
Respiration to release energy
What are tiny air sacs in the lungs called?
Alveoli
Define “diffusion”
The moment of particles from a high concentration to a low concentration
Which gas diffuses from the alveoli (lungs) into the blood?
Oxygen
Which gas diffuses from the blood into the alveoli (lungs)?
Carbon dioxide
How do oxygen and carbon dioxide enter and leave the blood?
Diffusion between alveoli and blood supply
State three adaptations of the alveoli for efficient gas exchange.
1) Lots of alveoli to increase surface area; 2) Rich blood supply/Extensive capillary network; 3) Thin walls (one cell thick)
How can we measure lung volume?
Breathe into a tube placed in a plastic bottle of water and see how much water is pushed out
How else can we measure lung volume?
Breathe into a peak flow meter (measures litres/minute)
Name 3 harmful substances found in cigarettes
tar * nicotine * carbon monoxide
Which disease destroys the alveoli?
Emphysema
Which cells line the trachea to sweep the mucus and dust from the lungs?
Ciliated cells
