Respiration

• What happens to hemoglobin's affinity for O2 at higher partial pressures of O2?

  It increases, leading to greater saturation levels
• How does lower partial pressure of O2 affect hemoglobin during exercise?

  It increases O2 dissociation from hemoglobin
• What is myoglobin's affinity for O2 compared to hemoglobin?

  Myoglobin has a greater affinity for O2
• What factors affect O2 dissociation from hemoglobin during exercise?

  • Increase in body temperature
  • Increase in CO2 production
  • Increase in lactic acid production (decreases pH)
• What is the Bohr effect?

  It shifts the oxygen-hemoglobin curve to the right
• What does a greater diffusion gradient indicate for O2 dissociation from hemoglobin?

  More readily oxygen dissociates from hemoglobin
• What changes occur in respiration during exercise?

  • Increased external respiration
  • Increased internal respiration
  • Enhanced O2 supply to working muscles
• What is the term for hemoglobin fully bound with oxygen?

  Saturated or associated
• Where does oxygen association occur for efficient supply to muscles?

  In the lungs
• Where does oxygen dissociation occur to provide energy for work?

  In the muscle tissue
• What happens to venous blood returning to the lungs during exercise?

  It has higher CO2 and lower O2 partial pressures
• How does the diffusion gradient affect gaseous exchange?

  A greater gradient increases gaseous exchange
• What ensures hemoglobin is almost fully saturated with O2 in the alveoli?

  High partial pressure of O2 in alveoli
• What is required for greater O2 dissociation in muscle tissue during exercise?

  Increased O2 dissociation from hemoglobin
• What factors shift the O2 dissociation curve to the right during exercise?

  1. Increase in blood and muscle temperature
  2. Decrease in partial pressure of O2 in muscle
  3. Increase in partial pressure of CO2
  4. Increase in acidity (lower pH) due to lactic acid
• What happens to working muscles during exercise regarding heat and O2 usage?

  They generate more heat and use more O2
• What is the effect of increased lactic acid levels during exercise?

  It increases acidity and lowers pH
• How do the factors during exercise affect O2 dissociation from hemoglobin?

  They increase O2 dissociation, delaying fatigue
• What is the overall impact of increased O2 dissociation on muscle performance during exercise?

  It increases possible duration of performance
• What is the term for the attraction of oxygen to haemoglobin?

  AFFINITY
• Why must oxygen release from haemoglobin?

  It is required at the muscle cell
• What happens to the volume of oxygen released during exercise?

  It increases
• How does the partial pressure of oxygen affect its affinity to haemoglobin?

  As partial pressure decreases, affinity decreases
• What causes an increase in blood acidity during exercise?

  Increased production of Lactic Acid and Carbonic Acid
• What effect does reduced blood pH have on haemoglobin's affinity for oxygen?

  It reduces the affinity
• What is the significance of reduced affinity of haemoglobin during exercise?

  More oxygen is released to muscle cells
• What is Bohr's Shift and its significance during exercise?

  • Increased release of oxygen during exercise
  • Graph shifts down and to the right
  • Caused by reduced blood pH and increased acidity
• What happens to the graph representing oxygen release during exercise?

  It shifts down and to the right
• What is the site of gaseous exchange for carbon dioxide?

  Alveoli
• What is the partial pressure of carbon dioxide in the alveoli?

  Low partial pressure
• What is the partial pressure of carbon dioxide in the pulmonary capillary?

  High partial pressure
• What type of gradient exists between the alveoli and capillary for carbon dioxide?

  Steep concentration gradient
• What happens to carbon dioxide during gaseous exchange?

  Diffuses from blood into alveoli
• What is the site of gaseous exchange for oxygen?

  Alveoli
• What is the partial pressure of oxygen in the alveoli?

  High partial pressure
• What is the partial pressure of oxygen in the pulmonary capillary?

  Low partial pressure
• What type of gradient exists between the alveoli and capillary for oxygen?

  Steep concentration gradient
• What happens to oxygen during gaseous exchange?

  Diffuses from alveoli into blood
• How does the partial pressure of oxygen in the alveoli during exercise compare to at rest?

  It is the same as at rest
• What happens to the partial pressure of oxygen in the pulmonary capillary during exercise?

  It is lower due to internal respiration