2.) Give suitable explanations for the following:
(a) Breathing through the nose is said to be
healthier than through the mouth.
(b) Why does gaseous exchange continue in the
lungs even during expiration ?
(c) Why does a person feel breathlessness at higher
altitudes?
(d) Why do you shiver and why do your teeth chatter
when it is very cold in winter?
Answers
Answer:
(a) Breathing through the nose is said to be healthier than through the mouth because the hair present in the nostrils prevent large dust particles from entering inside the respiratory system.
(b) Gaseous exchange continues in the lungs even during expiration because expiration is the result of reverse movements of the ribs and diaphragm. As a consequence of the movements of the ribs and the diaphragm, the thoracic cavity is diminished and the lungs are compressed, forcing the air out into the atmosphere.
(c) At higher altitudes, the oxygen content of the air is low. So, a person feels breathlessness at higher altitudes.
(d) In order to maintain the body temperature constant in very cold conditions in winter, heat production is increased by enhanced metabolic rate and increased muscular activity. Shivering and chattering of teeth involves a lot of muscular activity. That is why we shiver and our teeth chatter in winter in order to increase heat production in the body.
Answer:
HERE ARE THE SUITABLE EXPLANATIONS FOR THE GIVEN STATEMENTS:-
a. Breathing through the nose is said to be healthier than through the mouth as our nose contains a lot of hair inside the nose or nasal channel but our mouth does not contain any thing like that. So certain dust particles (SPM) may enter into the lungs if we breathe through our mouth and that might cause much trouble. But this possibility is avoided if breath with our nose.
b. Gaseous exchange continues even during expiration because when we exhale the content air of the lungs then some amount of air is still left in our lungs which is full of Oxygen and thus, the respiration process still continues. But while bringing the inhaled air that is the newer air into the lungs the previously present oxygen is used up and hence the inhaling and exhaling processes continue alternatively while respiration still continues.
c. At higher altitudes the density of the air is much low in concentration and hence the amount of oxygen present at higher altitudes is much lower in comparison to the lower altitudes. Hence, when a man goes to higher altitude he feels breathlessness, because there is not much oxygen to breathe in.
d. In very cold winters we shiver and our teeth chatter as they put our muscles to work and that requires energy. The energy invested requires respiration in our body that causes the formation of heat and that might keep the body warm and hence we intend to do these activities to keep ourselves warm.