Question

 Be familiar with these terminology: bronchodilation, bronchoconstriction, airway resistance

 Understand regulation of breathing ( medulla oblongata and pons) Specifically, what stimulates peripheral chemoreceptors vs. central chemoreceptors.

 What are the effects of sympathetic nervous system and parasympathetic nervous system through the respiratory system? Understand ventilation/perfusion coupling.

 Understand Hb & O2 transport and oxygen-hemoglobin dissociation curve, specifically, how pH, BPG, temperature, PO2 , and PCO2 will affect oxygen affinity for Hb.

 What organ secretes erythropoietin(EPO) & what does this hormone do; understand which factors affect secretion of EPO. Understand the mechanism of Asthma as an obstructive

 pulmonary disease.

 Understand CO2 transport. Specifically, what are the 3 ways CO2 is transported in blood?

Answer 1

1. Bronchodilation - It is the process of widening of bronchi (airways) causes relaxation of lung muscles for easier breathing. It is used in treating the long term condition of inflammed airways e.g-in asthma.

Bronchoconstriction -It is the narrowing of bronchi of lung due to the tightening of smooth muscles present in lung.This kind of condition has been seen in lung diseases such as emphysema and asthma.

Airway resistance - It is the resistance generated in the respiratory passage due to friction in the airway during inspiration and expiration.

2.The medulla oblongata transmit the signal to the respiratory muscle that initiate the inhalation and exhalation and also control the nonrespiratory reflexes(cough,sneezing) as well. The pons controls the stimulating apneustic centre and limiting pnuemotaxic centre in order maintain rate of breathing.

Central chemoreceptor gets stimulated by the chnage in pH of the spinal fluid where as peripheral chemoreceptor gets stimulated by alteration in blood oxyeng and blood carbon dioxide.

3. The activation of sympathetic nervous system controls the bronchodilation of the airways whereas the activation of parasympathetic nervous system controls the bronchoconstriction the airways.

4. In order to maintain the efficient gaseous exchange, ventilation and perfusion should be coupled. That is meant by more blood flow in past functional lung than the past nonfunctional lung. The ventilation is associated with in and out flow of air in the alveoli where as perfusion is meant by the flow of blood to the alveolar capillaries.