L19

Question 1

What is the percentage of each gas pressure within the atmosphere?
- N2
- O2
- CO2
- h2O

Answer 1

• 78.6% nitrogen
• 20.9% for oxygen
• 0.04% of CO2
• 0.46% of H2O

Question 2

What is the pressure and percentage of each gas in the ALVEOLI?

Answer 2

• N = 75.4% = p = 570 mmHg
• Oz = 13.2 % = p = 100 mmHg
• C02 = 5.2 % = p = 40 mmHg
• h2O = 6.2% = 47 mmHg

Question 3

What is DALtons LAw?

Answer 3

It states that the pressure exerted by a mixture of gases is the sum of the pressure of each of the gas within the mixture

Question 4

Can describe the pressure of the gases within the pulmonary circuit and how this ensure efficient exchange of CO2 and O2?

Answer 4

• in lungs = Blood returning from the tissues has Oxygen at very low pressure of 40, whereas in the alveoli the pressure of oxygen from atmosphere is 100, so oxygen moves down pressure gradient into capillary
• Co2 pressure from blood returning from tissue is 45 mmHg as working tissue produce c02 as waste, and in the alveoli is 40 mmHg, Co2 moves from high pressure CAPILLARY into low pressure alveoli
  This makes blood in capillary to O2 100 mmHg, and Co2 in 40 mmHg

Question 5

Hoe does pressure of CO2 and O2 ensure an efficient exchange in tissues?

Answer 5

• arteries bring in blood , with oxygen at 100 mmHg and Co2 at 40 mmHg
  In tissues Oxygen is used up so in tissues O2 = 95
  In tissues Co2 is PRODUCED so O2 = 45 mmHg
  O2 moves from blood into tissue down pressure gradient
  Co2 moves moves from tissue into blood down pressure gradient

Question 6

What does Henry’s law state?

Answer 6

Amount of gas that dissolves in water depends on its solubility and partial pressure in air

Question 7

What is the blood flow to tissues?

Answer 7

5L per minute

Question 8

What is the blood flow to tissues?

Answer 8

5L per minute

Question 9

What amount of O2 does haemoglobin approximately transport?

Answer 9

97%

Question 10

What can affect the binding of O2 to haemoglobin?

Answer 10

• pH
• CO2
• temperature
• State of O2 binding to the Hb molecule

Question 11

What does decrease in pH, increase in CO2 do to the dissociation curve? what is it called and how does it improve gas/O2 exchnage

Answer 11

• decrease in pH and increase in CO2 shift curve to the right
• it is called bohr shift
• They affect structure of haemoglobin making it easier to UNLOAD at tissues

Question 12

How does TEMPERATURE affect the dissociation curve?

Answer 12

• working tissue, higher temp
• shift curve to the right
• more unloading of O2

Question 13

What is 2-3 DPG and how does it affect the dissociation curve?

Answer 13

• ## 2-3 DPG

Question 14

What 3 other type of haemoglobin do we have?

Answer 14

• Carboxyhaemoglobin
• Methaemoglobin
• Foetal haemoglobin

Question 15

Carboxyhaemoglobin, what does it bind to?

Answer 15

haemoglobin binds to carbon MONOXIDE
- binds very tightly
- dramatically reduce ability of O2 to bind to haemoglobin

Question 16

Methaehaemoglobin, what is it how does it affect haemoglobin?

Answer 16

• It is when Fe2+ in the haemoglobin converts into Fe3+
• unable to carry oxygen

Question 17

How does foetal haemoglobin differ from normal haemoglobin?

Answer 17

• 2 alpha and 2 gamma instead of 2 beta

Question 18

How is C02 carried in the blood in terms of percentage?

Answer 18

• 70% of CO2
• 23 % carried by haemoglobin carbaaminohaemoglobin
• 7% is dissolved in plasma

Question 19

CO2 produced in tissues, 70% of is turned into hCO3-, forming H+, this means that pH becomes veryyyy acidic, how is this prevented?

Answer 19

• Red blood cell haemoglobin contain the group IMIDAZOLE which acts a buffer minimising pH

Question 20

What is the HALDANE effect in LUNGS?

Answer 20

• Oxygenation of the lungs
• LOWERS affinity for H+
• Buffering power is decreased
• RELEASE of H+
• aids unloading of CO2

Question 21

What is Haldane effect in the tissues?

Answer 21

• DEoxygenation of Hb
• INCREASES affinity for H+
• buffering power increases
• H+ uptake