The Indian physician agreed with this and the Imam sadiq said:

This is not knowledge of book; it is a divine bestowal. After that he posed the following questions to him: 

(1). Why are the tears and other moistures housed in the head?
(2) Why the hair grows from the head? 
(3) Why there is no hair on the forehead?
(4) Why are there wrinkles on forehead?
(5) Why eyelids cover the eyes? 
(6) Why is the nose placed between the eyes?
(7) Why are eyes almond shaped? 
(8) Why is the aperture of nose facing downwards?
(9) Why are there two lips over the mouth?
(10) Why are the front teeth sharp and the morals broad? And why there are canines and premolars between them.
(11) Why are both palms hairless?
(12) Why men have facial hair?
(13) Why there is no sense in nails and hair?
(14) Why is the heart shaped like a cone?
(15) Why the lungs are divided into two parts and why does it move at its place? 
(16) Why is the liver convex shaped? 
(17) Why is the kidney shaped like a bean?
(18) Why do knees bend forward?
(19) Why are both feet hollow in the centre?

The Indian physician was bewildered by these questions and realized that he was not
connected to the art of medicine; he was in fact connected to secrets of creation and mysteries of universe and mysteries of universe could not be exposed, except by representative of creator of universe. So he asked the Imam to explain all these points and Imam (a.s) replied them in proper order.

(1) If the head had not been the center of moistures, it would have burst due severity of heat.
(2) If the head was hairless oil would not have been able to reach to the roots and the brain would have not been safe from cold and hot. 
(3) The forehead is hairless as from there light reaches to the eyes. 
(4) There are wrinkles on forehead to protect the eyes from sweat etc.
(5) Function of eyelashes is to ensure that intensity of sun may affect as per need and there is ease in sleeping as well.
(6) Nose is placed between two eyes so that light could be divided in two
parts before reaching the eyes.
(7) Eyes are almond shaped so that Surma may be applied easily.
(8) The nose aperture is placed downwards so that moistures may be easily exuded. 
(9) Lips are shaped as such so that moistures coming from above may not enter the mouth and that food may not fall out. 
(10) Facial hair is given to men so that a difference can be maintained between men and women. 
(11) Incisors are sharp to enable cutting of a thing easily and molars are broad to chew the food easily and the teeth between them are long to keep them in order. 
(12) There is no hair in palms to enable touch and to perceive hardness and softness.
(13) There is no feeling in nails and hair as they have to be pruned again and again.
(14) Heart is conical so that it may enter the lungs easily and continue to be cooled through its air.
(15) Lungs have two sections so that the heart remains between them.
(16) Liver is convex so that it should remain just on top of the stomach and continue to digest food through its heat and weight.
(17) Kidney is shaped like bean, because semen comes to it from behind and is expelled slowly through its contractions and dilations.
(18) Knees do not bend backward to ease walking; otherwise one would fall down easily.
(19) The base of feet is hollow so that legs may rise easily when pressure is exerted on them; otherwise it would have been difficult to lift the weight of the whole body. After getting these replies, the Indian physician asked in astonishment: From where have you gained this knowledge? He said: From my respected grandfather and he received it from Holy Prophet and he in turn gained it through the Lord of the worlds. As soon as he heard this, he began to recite the Muslim formula of faith (Kalima) and after embracing Islam, said: Indeed, you have more knowledge than all the people of the time..

📚Ref- Masumin, Part 2, Pg. 25..