Biology exhange Flashcards
Function of smooth muscle in gaseous exchange
Involuntary muscle,
Contracts and causes the airways to constrict
narrows the lumen
Controles air flow to the alveoli
Function of cartilage in gaseous exchange
Supports airways
Keeps airways open
incomplete c shaped rings provide flexibility
Prevents collapsing when air pressures are low (inhaling)
Allows oesophagus to expand when swallowing
Likely effect of smoking on cilia and Goblet cells
Smoking damages the ciliated cells, and are paralyzed.
Stimulates goblet cells to secrete more mucus, and can lead to the diameter of bronchioles decreasing
Function of elastic fibres in the alveoli
Works with smooth muscle
When smooth muscle contract, they deform
when smooth muscle relax elastic fibres recoil and return back to normal shape, aiding airways to dilate
Describe how the Goblet and ciliate epithelial cells protect the alveoli from damage
Goblet cells secrete MUCUS, which is STICKY, TRAPS dust, viruses and pathogens Cilia beat in a SYNCHRONISED PATTERN Particles are WAFTED by cilia Mucus is SWALLOWED Pathogens KILLED BY ACIDITY OF STOMACH
Adaptations of a good gas exchange
LArge SA Thin barrier Diffusion gradient prevention from dryng out Maintains a steep concentration gradient
Path of CO2 from blood capillary to lumen of alveoli
Diffuses out of the capillary wall past the epithelial layer of the alveoli into the lumen of the alveoli
Why do people with emphysema have trouble forcing air out their lungs when they breathe out
Alveolus destroyed–> lack elastic fibres to stretch and recoil, widening the diameter of the airway when you breathe out
why do singled cell organisms not need a specialised area for gas exchange
- Gas exchange occurs through diffusion, single celled organisms are so small that their high SA:V allows diffusion to occur quickly due to the shorter diffusion distance
What happens to the air chamber during inspiration
Volume of air inside chamber decrease and the hinge drops down
What chemical absorbs CO2
Soda lime/ sodium hydroxide
- Why should someone measuring their vital capacity use a nose clip
Prevent air from escaping and leading to invalid results
Precautions taken when using a spirometer
- sterolize mouthpiece
- don’t use if you have asthma
- don’t use for more than 5 minutes, can lead to unconsciousness
How can a spirometer be used to measure tidal volume
Breather in- volume of air decreases, float/ pen falls down
Breather out- Volume of air increases, float/ pen rises
measure TV from peak to trough
How spirometer is used to measure oxygen uptake
- Measure the differece in volume of air at the beginning and end, measure the time taken for that total volume (end-beginning) 60 x vol
Explain using SA and V, why large active oragnisms require a specialised exchange surface
As an organism gets larger, their SA:V decreases
In order for effeicient exchange they need to find other ways to provide enough surface
How dot the lungs prevent drying out
- Alveoli are tucked away deep in the body, away from direct exposure
Cells secrete mucus and fluid that covers the lining and keeps them moist
How do the leaves increase surface area
Highly branched
Open air spaces mean more cell surfaces are exposed
How to plants ensure they have a steep CG
Photosynthesis means that CO2 is being used, low concentration inside palnts
O2 used for respiration at night, CG in opposite direction
Function of macrophages
Digest and engulf particulates from smoke. Bacteria that are harmful to alveoli, they are phagocytes
How does the mechanism of relaxed breathing out work
Intercostal muscles relax, diaphragm relaxes decreasing the volume of the thorax, the alveoli recoil and pressure inside is higher than outside
air is forced out
How does inspiration work
The external intercostal muscles contract, diaphragm contracts
ribcage moves up and out
volume of thorax increases
pressure inside
Forced Expiration
Internal intercostal muscles CONTRACT, volume of thorax decreases ribcage moves downwards and inwards Diaphragm RELAXES ABDOMINAL WALL CONTRACT, RAiSES PRESSURE IN ABDOMEN, raises diaphragm
The requirements of an effective airwya
Large enough for sufficient air to flow without obstruction
divide into smaller airways that can deliver air tp aveoli
strong enough to prevent collapsing during low pressures
flexible
stretch and recoil
