SMOOTH MUSCLE 45 



CILIATED CELLS. 



In addition to the muscular tissue of the body there are other 



contractile elements, viz., ciliated cells. 



The function of ciliated cells is to remove mucous and foreign 



bodies from passages. They are therefore found in the mucous 



membranes of the trachea, larynx, bronchi, nos.e, lachrymal duct, 



uterus, Fallopian tubes, tubules of the epididymis, Eustachian tubes 



and middle ear. 



Each cell may have one or more cilia. Not only the cilia of the 



same cell, but those of neighbouring cells, move in a definite 



sequence, so that there is co-ordination. 



The power of these cilia acting together is considerable. It is 



estimated that the cilia on 1 sq. cm. of the frog's oesophagus cap 



move a weight of more than 300 grams. 



Warmth increases the activity of cilia; cold decreases it. Drugs 



also influence their movement. 



Experiment 17. Ciliary Action. Remove the lower jaw of a 

 frog and slit the oesophagus. Spread open the oesophagus with 

 pins. Determine the time required for a bit of cork placed 

 on the roof of the mouth to be moved one centimeter down the 

 gullet. Keep the mucous membrane moistened with salt solu- 

 tion. Pour iso tonic NaCl solution, warmed to 30 C. over 

 the membrane, drain it off, then determine the rate of move- 

 ment of a bit of cork. After a time blow ether vapour over the 

 membrane and again determine the rate of ciliary action. 



