Respiratory system 6 Flashcards
What two forms is oxygen carried through blood
Dissolved O2
Bound to haemoglobin in RBCs
What does a right shift in the O2-haemoglobin saturation curve mean
Reduced pH (Bohr’s effect)
Increased PCO2
Increased Temperature
What does a left shift in the O2-haemoglobin saturation curve mean
Decrease PCO2
Increased pH (Bohr’s effect)
educed temperature
What three forms is carbon dioxide transported in
Dissolved in plasma (more soluble than O2)
As bicarbonate (70%) - binds to haemoglobin
Combined with proteins - carbamino compounds
How do we control amount of O2 and CO2
Tight control of ventilation
What are higher centres
Can alter activity of pneumotaxic centres
Cerebral cortex, limbic system and hypothalamus
What do apneustic and pneumotaxic centres do
Adjust output of the respiratory rhythmicity centres
What do respiratory rhythmicity centres do
Generate cycles of contraction and relaxation in diaphragm - pace of reparation
What are the respiratory rhythmicity centres
DRG - Dorsal respiratory group
VRG - Ventral respiratory group (inspiration and expiration centres)
What is the ‘pace maker’ of respiration
Pre-Botzinger complex
What are the two most important receptors that control respiration
Chemoreceptors - CO2 receptors
Baroreceptors - blood pressure (Aortic arch and carotid sinus)
What happens when arterial BP goes down
Baroreceptors sense reduced flow - increases respiratory minute volume and increases uptake of air
What happens when arterial BP goes up
Baroreceptors sense increased flow - Deceases Respiratory minute volume and decreases uptake of air
How do we control the stretching of our lungs
As inflate or delflate send afferent input from stretch receptors. Efferent output from brain preventing stretching too far
Why do we sneeze/cough
Receptors detect irritation - brain sends efferent signal to sneeze or cough
