the respiratory movements recorded are faster and deeper

the respiratory movements recorded are faster and deeper. This exercise hyperventilation returns to normal without any period of apnoea in between,

Discussion:

The normal respiratory rate ranges from 12-18 per minute. An increase in rate is called tachypnoea and a decrease in rate is called bradypnoea.

Chemical factors like arterial PC2, PCO2 and H ion concentration can influence the neural centres controlling breathing. This influence is mediated through the peripheral and central respiratory chemoreceptors. A decrease in arterial PC2, and increase in PCC2 or an increase in H ion concentration stimulates respiration. During voluntary hyperventilation, CC2 is washed out, this causes depression of respiration causing apnoea. During the period of apnoea, CC2 accumulates and breathing starts once again.

During deglutition, the respiratory centre is inhibited causing deglutition apnoea, this is a protective phenomenon which prevents entry of food and fluid into the respiratory passages.

During exercise, an increased production of CC2, along with an icnreased demand for oxygen, produce and increase in the rate and depth of breathing. Several other factors also contribute to this change. The breathing pattern gradually returns to normal without any period of apnoea, unlike in voluntary hyperventilation. This is because of the large amounts of CC2 being produced during exercise.

Periodic breathing: is irregular breathing with period of apnoea in between

Eg: Cheyne strokes breathing

This is characterised by waxing and waning type od breathing cycles followed by a period of apnoea. It is seen in congestive cardiac failure.

Biot’s breathing is another type of periodic breathing in which cycles of hyperventialtion with intermittent periods of apnoea occur.

Questions:

1. Briefly describe the regulation of Respiration.

2. What is the change in pattern of respiration during phonation?

3. What is the change in pattern of respiration during cough and sneeze?

4. What is the physiological basis for deglutition apnoea?

5. What changes are observed in respiration during moderate exercise? Give physiological reasons?

6. What is breaking point?

7. What are the factors influencing breaking point?

Reference on Medicinal plants  Part I

Reference on Medicinal plants Part II

reference on  Indian medicinal plants and its treatments.