The Respiratory System Flashcards
How do single cellular organisms take up oxygen?
Via diffusion. Cells have a large SA/V ratio and therefore the diffusion rate is high
How do humans (or other multi-cellular organisms) take up oxygen?
The outside of the body has a small SA/V ratio therefore, diffusion through body surface is not possible. As a result of this, gas exchange is used.
Gas Exchange (2 functions):
- Uptake of oxygen (for respiration)
- Release of carbon dioxide (waste products)
How is the respiratory system adapted for efficent gas exchange: (3 adaptations)
- Surface Area
- Concentration Gradient
- Diffusion Distance
How does surface area aid in efficent gas exchange?
The large SA/V ratio is due to alveoli having a bumpy shape. As of the folded shape and the quantity of alveoli, efficent gas exchange is possible
How does the concentration gradient aid in efficent gas exchange?
The concentration gradients allows for diffusion of carbon dioxide out and oxygen in. This keeps breathing and blood flow consistent
How does diffusion distance aid in efficent gas exchange?
The capillary wall is only one cell wall thick. As a result of the short distance, gas exchange is more efficent. The wall of alveoli too is only one cell wall thick.
Why is 21% of oxygen breathed in when only \ breathed out?
As oxygen has diffused from alveoli into blood
Why is 0.03% of carbon dioxide breathed in and 4% breathed out?
As carbon dioxide has diffused from blood into alveoli
What is 78% of Nitrogen breathed in and out?
As nitrogen is not used
Why is more water breathed out than in?
As water evaporated from alveoli surface
What is air breathed in variable whilst the air breathed out 37 degrees Celsius?
As heat is lost to the air form the lungs
Inhalation : Diaphragm
Contract - diaphragm flattens
Inhalation : External Intercoastal Muscles
Contracts - pulling ribs up and out
Inhalation : Rib cage
Moves out and upwards
Inhalation : Volume of chest cavity
Cavity increases
Inhalation : Lungs
Expand
Inhalation : Pressure
Lower pressur than outside body
Inhalation : Air
Rushed into the lungs to equalise pressure
Exhalation : Diaphragm
Relax - diaphragm becomes dome shaped
Exhalation: External Intercoastal Muscles
Contracting pulling ribs down and in
Exhalation: Volume of chest cavity
Shrinks (decrease)
Exhalations: Lungs
Decrease
Exhalation : Pressure in lungs
Higher pressure than the outside body
Exhalation : Air
Flows out of the lungs due to the high pressure
Tidal Volume:
Volume or air breathed in and out in a single breathe (approx. 0.5 litres)
Inspiratiry Volume:
Additional volume of air taken in with the deepest breath possible (up to 2l)
Expiration volume:
Additional volume of air that can be breathed out if we force it out (up to 1.5 litres)
Residual volume:
Air remaining in lungs after a maximum exhalation (approx. 1.5 litres)
Vital capacity:
The maximum volume of air that can be exhaled in one breath (4 litres)
The effects of excercise on ventilation:
1) ventilation rate increases (i.e. you will breathe more quickly)
2) tidal volum increases (breathe more deeply)
3) muscle contract more, so they need more energy for respiration, which provides them with energy
What is inside cigarettes?
Nicotine
Tar
Carbon monoxide
Other Products (e.g. cadmium, butane, methane, paint and etc.)
Short-terms effects of cigarette ingredients inside body
Smelly hair Smelly breath Less oxygen to brain and lungs Stained teeth and fingers More coughs + colds
Long term effects of cigarette on the human body?
Stroke Gum disease and tooth loss Mouth/throat/lung/stomach pancreatic cancer Heart disease/attack Emphysema Chronic bronchitis Decreased fertility Peripheral vascular disease
Tar build up in lungs:
Emphysema - chemicals in tar damaged alveoli
Lung infections, bronchitis - cilia in bronchioles paralysed , build up of mucus, debris in lungs not removed and build up of bacteria
Nicotine
Addictive substance in cigarettes - stimulates neurotransmitters in brain leading to more brain activity
Strokes and heart attacks - constricts arteries reducing blood flow, fat deposited in blood vessels and increases blood pressure
Carbon monoxide
Tiredness, dizziness, increases heart rate - bunch irreversibly to haemoglobin and so reduced oxygen carrying ability of red blood cells
Reduced birth mass - foetus gets less oxygen
