1. What should be the concentration of reduced haemoglobin of blood before cyanisis appears?
5 gm/100 mL (5 g/dL)
2. Why cyanosis does not occur in anaemic hypoxia?
This is because the total haemoglobin content in the blood is low
3. What else can produce discolouration of the skin and mucous membrane similar to cyanosis?
High circulating levels of Methemoglobin
4. What is conscious of shortness of breath known as?
Dyspnoea
5. What are the cells of carotid body known as?
The glomus cells
6. On exposure to hypoxia, which neurotransmitter is realesed from glomus cell?
Catecholamine / Dopamine
7. What is the principal transmitter released by glomus cells on exposure to hypoxia?
Dopamine
8. What types of ion channels are present in type I glomus cells?
O2 sensitive positive ion K ion channels
9. What happens to the conductance of ion channels in type I glomus cells as the degree of hypoxia is increased?
Conductance to positive ion K is reduced
10. As the the degree of hypoxia is increased, which ion triggers the depolarization of glomus cell?
Influx of positive ion Ca
11. What is the normal blood flow to each carotid body?
0.04 mL/min or 2000 mL/100 g tissue/min
12. Why carotid bodies are not stimulated in conditions of aneamia and CO poisoning?
The O2 needed by the cells are met largely by the dissolved oxygen
13. What is the FEV1 percent for normal adult?
80% of the vital capacity
14. Why is haemoglobin not 100% saturated at a PO2 of 100 mm Hg?
Due to the presence of arterio-venous shunts
15. What other chemical is carried along with O2 by haemoglobin from lungs to periphery?
Nitric oxide (NO)
( UMS, 2008 )
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