human body 

a living structure the skeleton consists of 206 separate bones , which differ in form size and name it supports and shapes the body protects the internal organs and in the bone marrow of certain bones manufactures various types of blood cells 

a perfect machine   

 How can we understand what we are?
                                   what are we made of ?are we aware
                                    that all that we do - including reading this contain

is the work of a marvelous machine? we know very little about how we are able to be conscious of our own actions: nevertheless< even though we are usually not very aware of it , this community of orangs that is the body-----an integrated system that includes the brain < heart < lungs, liver, kidneys,musicales,bones,skin,and endocrine glands-----

act together in exquisitely regulated harmony

. it is interesting that various mechanisms work together to keep the temperature of the body at 98.6ْ (37ْc)
thanks to the dynamic structure of bones and cartilage , the body is maintained in perfect balance . the body is maintained in pefect balance. the body also has  a fantastic ability to transform the food it ingests into living tissues, bones, and teeth , all of which contribute to its growth by this same process, we obtain the energy for working and playing it is hard to imagine that not long ago the cells of the body of the person reading this book were autonomous and were duplicating themselves freely within the walls of a motherَs uterus. 

certainly no one reading this book could recognize hereself or himself in those cells . nevertheless, each cell carried within it the information necessary for the development of that person everything that happens inside us is truly fascinating . therefore, we invite yuo to enjoy this book , it is full of incredible facts  and illustration that will show yuo the complex ways each parts of the body works.

what are cells like

 and how do they form tissue ?  what is blood , and why are proteins so important? the heart , usually thought of as the wellspring of love  and the emotions is actually the engine of the circulatory system . it is because of the heart that all the cells of  the body receive a constant supply of nutrients , oxygen , and other essential substances, the heart is so powerful that it pumps about 10 point (4.7) of blood per minute, the nervous system is the most intricate of all the bodyَs systems it works every second of every day , gathering information about the organism and its surrounding and issuing can react it is this computer that permits us to think and remember and that makes us who we are.

he nervous system 

is a complex network of sensory cells, origination in brain and spinal cord , that transmits signals throughout the body , employing a caravan of chemical  messengers to make sense of this marvelous complex that we catalogue as touch , taste , smell , hearing , and  vision in fact at this precise moment , because of an extraordinary relationship between our eyes and our brain , we are reading , modern cameras are designed on the same basic principles as our eye , but they have never been able to equal the visual power of the eyu . the focus and the automatic aperture of the human eye are perfect , our ears share a similar complexity and allow us to have excellent hearing . the external ear operates by receiving sound waves in the air . sound waves travel through the auditory canal and are transmitted  by the bones of the intermediate ear toward the cochlea, which contains liquid and is spiraled like the shell of small sea snail.

the cochlea converts waves of air into vibration of liquid , which are detected by special filaments in the ear that are of many lengths and that detect sound waves of different lengths and that detect sound waves of different lengths  these filaments then transmit nerve impulses to the brain and provide us with our ability to interpret what we hear . this book will also tell you about the function of our skin the largest organ of the body , which serves as an elastic barrier covering and protecting every thing inside our bodies . captivating images will show you how each of our extraordinary body system function and incredible fact will help you understand why the human body is so amazing.