Lecture 44- Respiratory System Part 4

Question 1

How does the oxygen-hemoglobin saturation curve shift when temperature increases?

Answer 1

Shifts right

Lower affinity for O2 to bind at higher temps

Question 2

How does the oxygen-hemoglobin saturation curve shift when temperature decreases?

Answer 2

Shifts left

Higher affinity for O2 to bind at lower temps

Question 3

How does the oxygen-hemoglobin saturation curve shift when pH increases?

Answer 3

Shifts left

Higher affinity for O2 to bind at higher pH/less acidic

Question 4

How does the oxygen-hemoglobin saturation curve shift when pH decreases?

Answer 4

Shifts right

Lower affinity for O2 to bind at lower pH/more acidic

Question 5

Why is it harder for O2 to bind at acidic levels/what is happening?

Answer 5

Lactic acid/carbonic acid is building up in exercising muscle=cells become more acidic

Free H+ then binds to hemoglobin so O2 has a harder time to bind which lowers affinity

Question 6

How does the oxygen-hemoglobin saturation curve shift when CO2 increases?

Answer 6

Right shift

CO2 binds to Hb which lowers affinity for O2 to bind

Question 7

What is the role of carbonic anhydrase enzyme?

Answer 7

Reversibly transforms CO2 and H2O to a bicarbonate ions (HCO3-) and H+.

This process can occur without the enzyme, but it is sped up much faster with it

Question 8

Overall, what are the four factors that affect O2 affinity to bind?

What is the main way you achieve all three of these?

Answer 8

1. Increase temp
2. Decrease pH
3. Higher levels of CO2
4. High levels of 2,3-BPG

Question 9

What does 2,3-BPG do?

Answer 9

Increases temp and decreases pH=lower O2 affinity when 2,3-BPG levels are high

Question 10

Explain when high and low O2 affinity means for the tissues and lungs

Answer 10

When oxygen affinity is low, it’s easier for tissues to access oxygen as it’s released more readily from hemoglobin.

When oxygen affinity is high, hemoglobin binds oxygen more readily, aiding oxygen uptake during respiration in the lungs

Question 11

What is Acidosis?

Answer 11

When pH decreases=less O2 affinity=right shift

Question 12

What is Alkalosis?

Answer 12

When pH increases=more O2 affinity=shifts left

Question 13

If the blood is too acidic, what direction will carbonic anhydrase make ions combine with?

Answer 13

H+ and HCO3- combine to break into CO2 and H2O

Question 14

If the blood is too basic, what direction will carbonic anhydrase make ions combine with?

Answer 14

CO2 and H2O will combine to break into H+ and HCO3-

Question 15

What law explains diffusion into tissues based on partial pressure?

Answer 15

Fick’s Law

Question 16

Why does hemoglobin give up oxygen in the tissues?

Answer 16

pH change

Bohr effect

Question 17

What is the Bohr effect

Answer 17

Explains how pH affects the binding of oxygen to hemoglobin

Question 18

How does a lower pH affect Hb’s affinity for oxygen? Where does O2 go as a result?

Answer 18

Lower pH (acidic conditions) reduces hemoglobin’s affinity for oxygen, aiding oxygen release in tissues

Question 19

How does a higher pH affect Hb’s affinity for oxygen? Where does O2 go as a result?

Answer 19

Higher pH (alkaline conditions) increases hemoglobin’s affinity for oxygen, enhancing oxygen uptake in the lungs

Question 20

What is the Haldane effect?

How does it alter CO2 and O2 affinity?

Answer 20

How oxygen concentrations determines hemoglobin’s affinity for CO2

Binding of O2 displaces CO2 which reduces Hb’s affinity for CO2 and increases affinity for O2

Left shift

Question 21

How is O2 and CO2 mainly transported?

Answer 21

O2- hemoglobin

CO2- bicarbonate

Question 22

How does a higher partial pressure of CO2 affect bronchioles diameter?

Answer 22

Diameter increases (bronchodilation)

this aids in ventilation to remove excess CO2 from the body

Question 23

How does a lower partial pressure of CO2 affect bronchioles diameter?

Answer 23

Diameter decreases (bronchoconstriction)

Helps retain CO2 in the body

Question 24

When is gas exchange more engaged?

High or low PCO2?

Answer 24

High PCO2

Bronchodilation with high PCO2=less resistance

Question 25

What is the chloride shift/where does it take place?

Answer 25

The chloride shift refers to the movement of chloride ions into red blood cells (RBCs) in exchange for bicarbonate ions during gas exchange in tissues

Question 26

What is reverse chloride shift/where does it take place?

Answer 26

Reverse chloride shift occurs in the lungs, where chloride ions move out of RBCs and bicarbonate ions move back in, helping to prepare blood for CO2 exhalation