Oxygen-Hemoglobin Dissociation Curve at Rest/Curve Shifts

How is most oxygen transported in the blood?

Hemoglobin

What percentage of oxygen is transported bound to hemoglobin?

98.5%

Approximately what percentage of oxygen is dissolved in plasma

1.5%

What does the oxygen–hemoglobin (O₂–Hb) dissociation curve shows?

Hb is almost completely saturated when P_O2 is 80 mmHg or above

At lower partial pressures…

the hemoglobin releases oxygen

What does a rightward shift of the oxygen–hemoglobin dissociation curve indicate?

decrease in pH, Increase in CO2, or Increase in Temperature

All result in a _____ in the ability of hemoglobin to hold when the graph shifts right.

decrease

What does a leftward shift of the oxygen–hemoglobin dissociation curve indicate?

Increase in pH, decrease in CO2, or decrease in temperature.

All result in an ________ in the ability of hemoglobin to oxygen.

increase

When the curve shift to the right, the tissue is

metabolically active

When curve shift to the left, the tissue is

not as metabolically active

A decrease in pH (more acidic conditions) will cause the curve to have:

Bohr Effect

BoHr Effect

At a certain partial pressure of oxygen, hemoglobin is less saturated.

As Temperature increase,

hemoglobin’s oxygen saturation decreases.

Less oxygen can bind to Hb, so….

more oxygen is released Hb to tissue

What is the primary purpose of hemoglobin unloading O₂?

To match metabolic needs of different states of activity of the tissues

What three factors that adjust the rate of oxygen unloading from Hb?

Ambient P_O2, Temperature, & Bohr effect (pH)

Ambient P_O2

Active tissues has decrease PO₂ & O₂ is released from Hb

Temperature

Active tissue has increase temp & promotes O₂ unloading

Bohr effect (pH)

Active tissues has increase CO₂, which lowers pH of blood & promoting O₂ unloading

Which one of the factor is most potent stimulus for affecting breathing rate is the pH of blood?

Bohr effect (pH)