The Oxygen Dissociation Curve Flashcards
During maximal exercise…
CO2 diffuses into the blood - lowers the % affinity of haemoglobin for O2
Therefore more oxygen is given up to the maximal exercise site
When exposed to alveolar air…
98% of haemoglobin is saturated with O2
What happens when we exercise?
More CO2 is produced - % CO2 increases - tissue working harder
pH become more acidic - more O2 delivered to acidic sites (work harder)
Body temperature increases - more O2 is delivered to warmed up tissue
The Bohr shift depends on the…
Exercise intensity
Atriovenous difference (a-VO2) is…
How much oxygen is actually extracted and utilised by the muscles
At rest: blood is saturated with …
Oxygen at the alveolar capillaries 96%
Return via pulmonary artery it is sill saturated with O2 70%
At rest our muscles only use 25% of O2 delivered to them
This difference = 45ml of O2 per 100ml of blood
a-VO2 difference can increase 3 fold during…
Exercise
Up to 15ml of O2 per 100ml of blood
Rest= a-VO2 diff = 5/100 ml Exercise= a-VO2 diff = 15/100ml
How is CO2 transported in the blood?
70% as carbonic acid
23% combines with haemoglobin to form carbaminohaemoglobin
7% dissolved in blood plasma
The control of breathing:
Respiratory control centre in mela impulses sent by chemoreceptors
Inspiratory control centre
Expiratory control centre
Nerve impulses to respiratory muscles surrounding the lungs
Breathing pattern at rest :
Controlled by ICC
ICC sends nerve impulses to diaphragm and external intercostal muscles
During exercise:
Rate and depth increases
More impulses from the ICC
Carbon dioxide in blood:
Chemoreceptors (stretch receptors)
Detect low blood pH
Impulses to RCC
ICC & ECC increase impulses
When the oxyhemoglobin dissociation curve shifts to the right it is…
Bohr shift
The Bohr shift shows us that the haemoglobin likes to release oxygen more…
Readily into the body tissues
Myoglobin has a curve to the left of haemoglobin because it has a…
Higher affinity for oxygen
