Respiratory System
- Why do we need this respiration thing?
- Need 02 in body for aerobic respiration, to make ATP
- Need to get the CO2 out!
- Some vocab, might be important
- Ventilation
- Exchange of air between lungs and atmosphere
- Gas Exchange
- The exchange of CO2 and O2 in the alveoli and blood stream via passive diffusion
- Cell Respiration
- Release of ATP from organic molecules
- Gas Exchange
- O2 and CO2 exchange between environ and cells
- Need a moist membrane
- Moisture maintains cell membrane structure
- Gasses only diffuse when dissolved in WATER
- High Surface Area
- Maximizes exchange rate
- CO2 and O2 move across cell membrane via diffusion
- Path through the system:
- In through schnozz, through pharynx, past epiglottis, larynx, trachea, bronchi, bronchioles, alveoli. The Diaphragm goes up and down, the ribs squeeze and release
- Alveoli
- Singular- alveolus
- Total surface area ~100m
- TRIM
- Thin walls
- Rich capillary network
- Increase in SA/Volume ratio
- Moissst
- Pressure is important!
- Air flows from high to low pressure- regulated by ribs and diaphragm
- Partial pressure is the pressure exerted by a single gas type in a mix of gasses
- This partial pressure depends on:
- Concentration of the gas in a mixture of gasses
- The total pressure of the mixture
- Air pressure decreases at high altitudes!
- Automated breathing control
- Medulla sets rhythm
- Monitors the CO2 level of the blood
- As such, monitors the pH of the blood!
- CO2 becomes H2CO3 (carbonic acid)
- If pH decreases, then the depth and rate of breathing increases- CO2 must be eliminated
- Pons moderates the rhythm.
- CO2 transport ! OOH BOY
- CO2 diffuses into plasma, then into RBC
- Binds to H2O to make carbonic acid
- One hydrogen breaks off and attaches to hemoglobin
- Leaves Hydrogen Carbonate
- Hydrogen Carbonate exits and is replaced by a chloride molecule.
- Go to Alveolus, where this is repeated in reverse
- This is called CO2 Buffering!
