Lecture 22

Question 1

In which different ways is oxygen transported in the blood?

Answer 1

1. 5% is dissolved in plasma

98. 5% is bound to haemoglobin

Question 2

What are the partial pressures of oxygen and carbon dioxide in the pulmonary arteries and veins

Answer 2

Arteries: Oxygen= 40mmHg
Carbon dioxide=46mmHg
Veins: Oxygen=100mmHg
carbon dioxide= 40mmHg

Question 3

What are the partial pressures of oxygen and carbon dioxide in the systemic arteries and veins

Answer 3

Arteries: Oxygen = 100mmHg
Carbon dioxide= 40mmHg
Veins: Oxygen = 40mmHg
Carbon dioxide = 46mmHg

Question 4

What factors would increase the affinity of Hb for oxygen

Answer 4

Increase in pH
Decrease in carbon dioxide conc.]
Decrease in temperature

Question 5

In which different ways is CO2 transported in the blood?

Answer 5

8% dissolved in plasma
12% binds to haemoglobin
80% is carried as bicarbonate

Question 6

Which nerve controls respiration

Answer 6

The phrenic nerve provides the nerve supply to the diaphragm

Question 7

List the peripheral chemoreceptors

Answer 7

Aorta and Carotid arteries

Decrease in pO2 or increase in pCO2

Question 8

List the central chemoreceptors

Answer 8

Medulla

Decrease in pH of cerebrospinal fluid or increase in pCO2

Question 9

Describe the effects of high altitude

Answer 9

Atmospheric pressure decrease
Partial pressure of oxygen decreases
Less saturated haemoglobin 
Tissues receive less oxygen
Insufficient ATP 
Increased cardiac output and ventilation

Question 10

Describe the adaptations to high altitude

Answer 10

Increased red blood cell number
Increase myoglobin
Increased mitochondria 
Increased vascularisation of the muscle
Increased respiratory enzymes
Lactate clearance (improved buffering of pH)