Physiology 4: Respiration Flashcards
What does respiration require?
O2 and C6H12O6
What are the by products of respiration?
CO2 and H20
What are the issues that must be overcome in respiration?
O2 and glucose need to get to the cells
Co2 is toxic
Gases cross surface by diffusion only
Label the gas exchange formula (add photo)
R = rate of diffusion
ΔP = Diff in partial pressure
A = Surface area
T = Temp
S = solubility
D = distance
Mw = molecular weight
What are the 3 general components of respiratory systems?
- Specialised surface where gas exchange takes place → need to be wet
- Breathing mechanisms to bring fresh air / water to the surfaces
- In some organisms circulatory mechanisms for transporting gases
Describe the process of respiration in insects
- Air diffuses in through spiracles
- Enters tracheae
- These branch into tracheoles
Describe how insects use active ventilation
Trachea inflate and deflate to pump air through
Larger may also exhibit rhythmic body movements
Tidal ventilation via spiracles
Why do insects close their spiracles?
Prevents water loss
Prevents debris from entering
Why do insects have a high water loss potential?
Because they have a large SA:V
How do insects maintain water loss
Must balance between losing water and gaining O2
Hairs around spiracles =decrease the diff gradient of water mols
Evolved hard cuticle
Close spiracles when environ is dry → air sacs store air
In vertebrates, describe what happens to Hb O2 affinity at lower temps.
Higher O2 affinity
In vertebrates, describe what happens to Hb O2 affinity at higher temps.
Lower affinity
Describe the Bohr effect.
(ore acidic) lower pH = lower affinity so haemoglobin readily dissociates O2
Co2 reacts with H2O = carbonic acid
Co2 dissolved in water lowers pH
Anaerobic resp = lactic acid (lowers pH)
In vertebrates, describe what happens to Hb O2 affinity at higher pH.
Lower affinity
In vertebrates, describe what happens to Hb O2 affinity at lower pH.
Higher affinity