Question

Sarah Johnson, aged 42, is 32 weeks pregnant and decides to go mountain hiking. She is unable to breath and airlifted to the nearest hospital. She is diagnosed with pulmonary oedema. Using your knowledge of oxygen transport (M2L5), answer the following questions. Be sure to clearly label the different parts. Part A. Describe two (2) factors that led to decreased gas exchange and her inability to breath. Part B. Explain why Sarah would have elevated levels of 2,3-bisphosphoglycerate and how this will impact oxygen delivery to tissues. (1 mark) Part C. Explain why the decrease in partial pressure of oxygen will affect the mother more than the foetus. (1 mark) Part D. The baby was delivered prematurely. Explain why he was placed on a ventilator due to collapsed lungs. (1 mark)

Answer 1

Part A. The teo factors that makes breathing difficukt at higher altitudes is :

1. less dense and colder air

2. less amount of oxygen dissolved in tge air.
Part B. 2,3- bisphosphoglycerate is a substance present in RBC which has hogher affinity to bind to deoxygenated hemoglobin. At high altitudes reduced availability of oxygen decreases the body content of oxygen. This increases the amount of deoxygenated hemoglobin. The   elevated levels of 2,3-bisphosphoglycerate helps bind to deoxygenated hemoglobin and promotes the release of the remaining oxygen to the tissues.
Part C The fetal blood follows a reverse concentration gradient of gas exchange. The fetal blood also has a higher hematocrit level and high agfinity for oxygen. Therefore mother is more affected than the fetus.
Part D. The lung surfact helps maintain the surface tension in the alveoli and prevent the collapse of lungs. The surfact is absent in premature baby which results in collaps of lungs.