Respiration and O2 Questions

Explain why each of these persons has trouble supplying Oxygen to their cells.

1. Someone without surfactant – this person cannot inhale because the surface tension inside the alveoli is so high it keeps them from expanding

2. Someone whose phrenic nerve is cut – this person cannot send the message to the diaphragm to constrict, so their inhalation is reduced

3. Someone who has depressed bone marrow due to chemotherapy – this person cannot make enough RBCs

4. Someone who has an enlarged spleen – the large spleen is destroying too many RBCs

5. Someone who has disseminated intravascular clotting in the pulmonary arterioles – blood isn’t flowing into the pulmonary capillary beds so it is not picking up O2.

6. Someone who has fluid in the alveoli due to pneumonia – the fluid is blocking the movement of O2 from air in the alveoli to the blood

7. Someone who has a malformed epiglottis due to a birth defect – the epiglottis is blocking the top of the trachea, so air cannot move in and out smoothly – or it is not blocking the trachea during eating and food is getting into the lungs.

8. Someone who has a stab wound perforating the body wall between the 5th and 6th ribs – air can move in through the stab wound when this person tries to inhale, instead of moving in through the trachea and filling the lungs.

9. Someone who has had both kidneys removed – cannot make erythropoietin

10. Someone who has reduced lung compliance - will have a hard time expanding his lungs

12. Someone who has reduced lung elasticity – will have a hard time exhaling as the lungs do not recoil and push the air out

More Respiration and O2 Questions

What effect will each of the following have on oxygen delivery to tissues? Why?

1. Alkalosis – this means there is less acid in the blood. Normally, acid can attach to hemoglobin (Hb) and knock O2 off. In this person the acid is not present to attach to Hb, so the Hb will continue to hold on to O2 and will not release it to the tissues.

2. Inability to make 2,3 DPG (some books call this BPG) – this compound binds to Hb and knocks off the O2, causing it to release more O2 to the tissues. If a person can’t make it, their Hb will hold on to the O2 and not release it.

3. Lack of iron in the diet – the person cannot make enough hemoglobin and cannot transport enough O2 around the body

4. Hemoglobin with an increased O2 affinity - the Hb will continue to hold on to O2 and will not release it to the tissues.

5. Acid injected into the cerebrospinal fluid – this will stimulate the central chemoreceptors and cause respiration to increase. More O2 will be inhaled.

6. A person with long-term bronchitis is given a high dose of O2 – in long-term pulmonary disease, pCO2 is high and pH is low. The central chemoreceptors have become habituated to this situation and are no longer responding. The person is only breathing at all because the peripheral chemoreceptors have kicked in. These stimulate breathing when they detect low pO2. By giving high levels of O2, the treatment has ‘fooled’ the peripheral chemoreceptors into thinking the person does not need to breathe. Although pO2 is high because of the treatment, it will soon go down as the client stops breathing. Also, pCO2 is rising and will soon send the client into a coma.