Give reasons for the following: (i) The glottis is guarded by epiglottis. (ii) It is said to not speak while eating. (iii) Walls of trachea are supported by cartilage rings.
(i) Glottis gets covered by a small cartilaginous flap of skin called epiglottis which prevents the entry of food particles into wind pipe while swallowing. (ii) The lung alveoli are richly supplied with blood capillaries for the exchange of gases. From the thin walls of alveoli, oxygen diffuses into blood and is supplied to the tissues while carbon dioxide is absorbed by blood from the tissues and is carried to the alveoli of lungs for exhalation. (iii) The walls of trachea is supported by C - shaped cartilage rings which does allow the trachea to collapse in the presence of less air in it.
