Diffusion & gas exchange Flashcards
Diffusion definition
- Diffusion is the net movement of particles form a high concentration to a low concentration - Passive process
—> Doesn’t require energy particles go along concentration gradient.
Factors affecting the rate of diffusion
1- Temperature
2- Surface area
3- Concentration gradient
4- Distance
Alveoli adaptations
- Thin - Short diffusion distance
- Large SA- Allows diffusion to occur effectively
- Good blood supply to maintain concentration gradient
The ………. Diffuses from the plasma of the capilaries into the alveoli and is breathed out.
Carbon dioxide
The ……….. diffuses from the alveoli into red bood cell and capillaries with the ……… to form ……….
Oxygen….. Haemoglobin … Oxyhaemoglobin
Gas exchange:
Process of absorbtion inhaled atmospheric oxygen molecules into the bloodsteam into the atmosphere.
Breathing
Process of taking air into and out of the lungs.
Nasal System
- Heating air
- humidifying air becasue of slow air turnover in this region
- dust and particles are filltered by short thick hairs, vibrissae in the nasal cavity.
Lining the Trachea
- Goblet cells -
- Ciliated cells
Alveoli
- This is where gas exchange with the blood occurs.
- Oxygen diffuses into the blood form the alveoli
- Carbon dioxide diffuses out of the blood into the alveoli
Pleural Cavity
- Pleural Membrane
- Pleural Fluid
Ribs
- Protects the lungs (clear)
Intercostal muscles
- Found in between each rib,
helps control the movement of air in and out of the lungs. (shaded)
Diaphragm
- Dome shaped muscle
- separating the content of the thorax from the abdomen
- controls the movement of air in and out of the lungs.
Ventilation
- Moving air in and out of the lungs
- Different in air pressure
- Air moves from high pressure to low pressure.
Breathing in
intercostal muscles - External contract - internal relax
Ribs - Up and out
Diaphragm - contracts - flatter shape
Chest - Volume increses
Air pressure - Inside thorax lower
Air movement - Moving in
Beathing out
Intercostal muscles - External relax - Internal contract
Ribs - in and down
Diaphragm -relaxes into dome shape
Chest - Volume decreases
Air pressure - Inside thorax higher
Air movement - Moving out
Tidal volume
- Volume of air inhaled and exhaled with each breath
Oxygen Dept
- Amount of extra oxygen required by muscles tissues to oxidise lactic acid and replensih depleted ATP after breathing at deeply as possible
Vital Capacity
- Amount of air that can be forcibly expelled from the lungs after breathing as deeply as possible.
Immediate effects of Exercise
- increased rate of breathing
- increase in tidal volume
Effects of regular exercise
- stronger diaphragm and intercostal muscles
- increased numbers of Alveoli
- Increase in vital capacity
- Increased rate of gas exchange
- more oxygen delivered
- More efficent romoval of carbon dioxide
Describe the effects of exercise on breathing rate
- breathing rate increase as the intensity of exercise increase.
- because …..you need to supply your muscles with more oxygen for aerobic respiration,
–>so more ATP can be released
Explain why breathing rate does not return to normal straight away (use key terms)
- oxygen debt, oxygen requires to oxidise lactic acid and replenish ATP.
investigating the effect of exercise on breathing- inhaled
limewater. - stay colourless
Hydrochloric carbonate indicator - stays red.
investigating the effect of exercise on breathing- exhale
limewater- turns milky white
Hydrochloric carbonate indicator- turns yellow
active transport
- movement of particles against the concentration gradient ( from a low concentration to a region of high concentration)
Pleural Membrane
Separates the thorax from the lungs.
It makes up a continuous envelope around the lungs, creating an airtight seal
Pleural Fluid
Lubricates the surface of the lungs.
Ciliated cells-
Covered in tiny hair- like structures ( cilia).
These beat backwards and forward, sweeping the mucus and trapped particles out towards the mouth.
Goblet cells
secrete mucus, this traps particles of dirt and bacteria.
