EARLY CONCEPTS. The Classical Greek philosophers considered the motions of the celestial bodies and of objects on Earth as basically unrelated. The former was not Considered as gravitationally determined as the Celestial bodies Were seen to follow perpetually repeating, non descending trajectories in the sky. Aristotle envisioned such bodies as possessing ‘natural’ motions that did not require external causes or agents. ln this view celestial bodies underwent their own particular ‘natural’ motion, While massive earthly objects possessed a natural tendency to move towards the Earth’s centre. Two other Aristotelian viewpoints were that a body moving at constant speed required a continuous force acting on it and that force must be applied by contact rather than interaction or force at a distance. These views impeded understanding of the principles of motion and hence retarded the development of a theory of universal gravitation. During the 16th and early 17th Century however, several scientific contributions to the problem of earthly and Celestial motion set the stage for Newton’s gravitational theory.
We all| know that gravity exists, for instance the fountain pen being used to Write this would not Work if it were held upside down. It is my theory that gravity plays a part in reducing the supply of blood to the scalp.
During ventricular relaxation blood pressure would drop to zero and blood would not flow at However, Continuous flow of blood in the large arteries is made possible by a layer of elastic tissues in the walls of the blood vessels (Figure 31).
When the heart squirts blood into the aorta, some of it forces the aorta to expand and some flows straight on towards the small arteries. Elastic recoil of the artery Wall then forces some blood along the artery, even when the heart is resting. Blood flow therefore becomes continuous, not stopping between each contraction of the ventricles. Smaller arteries have less elastic tissue in their Walls. They are regulators of blood flow and have a layer of muscle in their walls. The smallest muscular arteries are known as arterioles. As blood travels from the heart through the aorta up the external carotid artery, the temporal tract takes blood to the scalp as the blood enters the Capillary network of the scalp the blood pressure drops. The greatest drop in pressure occurs in the arterioles and capillaries, Where the diameter of the Vessels decrease and there is Very large resistance to flow.
To add to this red blood cells have to be folded in half or lay flat in order to squeeze through a capillary White blood Cells which digest germs are even bigger than red Cells but fewer in number (500 red to white) these also have to squeeze along the Capillary Wall. As blood goes further down the Capillary the pressure drops even more..'Thus the head is always in the upright position. Even when we sleep we prop our heads up with pillows. Blood is pumped from the heart upwards to the brain, face and scalp. But there are no main arteries in the scalp. Hair grows quite well on the sides and back where there are arteries and an abundant supply of blood.
Blood being pumped from the heart to nourish the hair papilla is being hindered by the force of gravity. But don’t worry because it is by the same force that We are going to correct the supply to the hair papilla. As blood travels up the main artery up to the side of the head, it enters the capillary network of the scalp. The blood that enters the capillary network is left to make its own way across the scalp, but let me try and explain by the means of a diagram what is happening.
The blood flow indicated with the larger arrows must travel quicker than that flowing in a more upward direction, in order for the blood to flow quicker you need more blood. So the majority of the blood is falling away to the side.
Feel your hair at the back and sides, you must notice that it is thicker than the top of your head. The reason being because it is getting a rich supply of blood.
Let me try and prove to you by the means of a simple experiment how gravity affects the blood flow of the human body Whilst you are reading this book stand up, take the book in your left hand and hold your right hand down by your pocket. Relax your hand and leave it there for thirty seconds, look at the veins in your right hand, by this time they must be standing out (full of blood). You should be able to see them quite clearly. Now while holding the book in your left hand raise your right hand to about eye level. Watch how quickly the blood runs back out of your hand, the veins almost disappear.
