Man - Incredible Machine

[Music] from cave wall to billboard uniquely human creation called Art has celebrated Nature's unique creation the human body science too has much to tell us about ourselves chemistry and physics that no machine designed by man can [Music] duplicate a close look reveals our evolutionary Heritage male and female alike our bodies hold as many hair follicles as our relatives the [Music] chimpanzees packed with nerve endings our lips are among the most sensitive parts of the body look closely at lips and tongue and Marvel at their versatility look closer still at the tip of the tongue magnified 60 times and Marvel merely at the sight [Music] Beauty we say is in the eye of the beholder but all we ever see of one another skin surface and hair is dead our skin is constantly growing from within creating new cells that push their way outward then die near the surface the whole process takes about a month weighing about 6 lb the skin is the largest single organ of the body yet it's only about a 20th of an inch thick The Ridges of our hands evolve to help us hold on to things our fingertips hold 2,000 pores per square in [Music] this giant Cavern is merely a single pore magnified 2400 times the green spheres are bacteria always present no matter how often and vigorously we may wash some 2 million such Caverns cover the body part of our efficient cooling system heavy exercise can raise internal temperature up to 7° above normal the body dissipates this excess heat through the evaporation of perspiration on the skin only a quarter of the energy we produce by muscular exertion is converted into work the remaining 3/4 is heat we usually associate perspiration only with heavy exercise or extreme heat but even under normal conditions we perspire constantly between 1 and two pints a [Music] day these bizarre scenes show variations in temperature from one part of the body to another they're made not by visible light but by heat on a machine so sensitive it can record heat left behind by a hand print or a moving finger on a [Music] wall used medically as an aid to detect tumors and to diagnose the severity of burns the thermovision camera converts invisible heat radiation into color video signals each color represents a difference of 1° f blue generally represents coolest temperatures red or white the [Music] warmest not only does the skin help cool and protect the body it also serves as a sense organ it seems likely that before birth the fetus receives most Sensations through the skin from the moment of birth humans seem to require touching and physical affection as much as food oh a pretty it's going to be so big when you get older yeah you are uhhuh as the infant grows it will rely more and more on other senses we are basically visual creatures receiving about 90% of all our information through our [Music] eyes we're constantly blinking once every 2 to 10 seconds bathing and lubricating our eyes with tears and someone has calculated that blinking causes our eyes to be closed for half an hour out of each waking [Music] day our Iris can adjust to changes in light intensity up to 1,000 [Music] fold the lens of the eye inverts images projected onto the retina exactly how we perceive everything right side up is still not fully understood lubricant tear containing an antiseptic agent that helps defend against disease many animals produce tears but as far as we know only humans weep as a result of emotional stress the range of human hearing is exceeded in nature by that of many kinds of creatures but our hearing sensitivity is remarkable a good ear can discriminate some, 1600 different [Music] frequencies inside the ear sound vibrates the eardrum shown here slowed down 200 times three tiny bones move vibrations along for conversion to electrical impulses and reception by the brain the tanic muscle protects the delicate apparatus against excessive noise watching the muscle move we can see the ear here hello uh this is uh her sister oh I see oh just a minute Karen Karen do you know a boy named [Music] Walter Walter last name is Brent throughout history individuals forced to cope with the loss of specific bodily functions have inspired us all with their courage stamina and skill okay just a second let me see if she attempts to repair or replace faulty Parts occupy many medical researchers almost every day brings new advances in electronics engineering and exotic synthetic materials through microsurgery and other radical techniques doctors seek ways to help overcome loss of sight and hearing this California college student was born DEA now she has just had an electronic implantation in her inner ear a bold new surgical procedure thus far tried on only a handful of patience [Music] very faint she said okay [Music] keep for the first time she hears the sound of her own voice [Music] the implant does not provide normal hearing but in most cases has brought at least a perception of sound where none existed before at the keyboard here on kac's commuter Classics The Pianist [Music] Alfred the enormous range of human sounds is the product of an exquisitely complex system the meaning of speech the aesthetic of song can be altered by minute movements involving diaphragm lungs windpipe mouth nose tongue lips teeth the actual sound created by the vocal cords alone is simple and faint [Music] a cough this slowed down 200 times is what happens to our vocal cords when we cough releasing trapped air with explosive force these wild undulations are but a single CA in an intricate lifegiving exchange we take in about a pint of air with each relaxed breath around 14 each minute inside we work somewhat like a Bellows the diaphram pulls down chest wall expands and air rushes in to fill the parti [Music] vacuum the trachea or windpipe splits into two large tubes the broni one going into each [Music] lung smaller broni Branch off into even smaller passages much like branches and twigs growing off from a tree trunk the entire gracefully swaying structure is often referred to as the bronchial tree the tiniest Twigs of the tree terminate in the Alvi 300 million microscopic air sacks which constitute the bulk of lung tissue entwined with clusters of Alvi a network of capillaries microscopic blood vessels air saac and blood vessel lie side by side through incredibly thin transparent membranes red blood cells snatch up oxygen and surrender waste carbon dioxide to be exhaled [Music] responding to stress the intertwined systems respiration and circulation display remarkable adaptability lungs and heart can perform prodigiously pumping about 10 times the amount of air and blood we need when we relaxed the heart's double barreled pumping action propels blood through the system under great pressure this is how it sounds recorded with a tiny microphone inside a living body blood the River of Life Journeys endlessly through 60 ,000 miles of blood vessels blood's main function is carried out at the cellular level oxygen water and nutrients are delivered to to each body cell and waste products are collected a complete tour out from the heart and back takes less than a minute from vessels 1 in in diameter to capillaries and venules so small that blood cells must line up to squeeze through one at a time [Music] at all times even during the most common place of our daily routines our bodies are the scenes of dramatic action facing the threat of invasion by hostile bacteria or other foreign organisms the body mobilizes for defense among its donut-shaped red cells the bloodstream contains a small highly mobile Strike Force lucaites white cells wriggling about under its own power a Lucas site seeks out attacks and consumes a foreign invader the white blood cells are both Warriors and scavengers in addition to their Battlefield duties they help cleanse the bloodstream of debris [Music] built of thick and tough muscle the heart is a Marvel of mechanical performance beating about 70 times a minute it pumps 2,000 gallons a day one-way valves prevent blood flow from backing up merely the size of a fist and weighing less than a pound the hearts Dynamo pumps 55 million gallons in a [Music] lifetime no longer regarded as the Temple of the Soul or the seat of intelligence the heart and its corridors nonetheless Inspire awe and reverence for the beauty and efficiency of Nature's [Music] design as science probes ever deeper into the secrets of nature knowledge takes on an aura of fantasy we learn for example that a single cell of heart muscle continues to beat even when removed from the heart [Music] in another laboratory experiment two heart cells in a culture dish beat individually each at its own pace but when they touch they synchronize and beat in [Music] unison to utilize raw materials that build tissue and supply energy the human body employs a complex chemical conversion process despite frequent abuse our digestive system routinely performs extraordinary Feats of chemistry even before the first bite the mouth prepares by increasing secretion of saliva mostly water saliva helps chewing and swallowing and contains enzymes that let begin the digestive [Music] process down the gullet or esophagus a tube 9 to 10 in Long less than an inch wide leading to the stomach like most of the digestive tract the esophagus is lined with muscles that squeeze and relax pushing food along every step of the [Music] way walls of the stomach churn the food and mix it with enzymes and acid in normal digestion the stomach produces hydrochloric acid strong enough to burn a hole in a rug but protects itself with a glistening layer of mucus in the overall digestive process the stomach serves largely as a way station most of the work takes place in the small [Music] intestine millions of tiny Villi lining the intestine help convert usable nutrients into forms the body can absorb total distance traveled between intake and out let 30 ft total time 1 day despite our wide variety of motion our muscles can do only one thing contract we're painting them red and blue flexors and extensors to show their arrangement in opposing pairs one muscle contracts to pull a bone forward its opposite number contracts to pull it back forward and back up and down the entire range of movement derives from muscles oneway action we have in all more than 600 muscles comprising about 40% of body weight our bones amazingly strong and light make up only 18% of our weight healthy joints are lined with a glassy smooth cartilage and lubricated by a thick fluid said to be so effective that nothing technology has produced can match it [Music] of the bodies 206 bones more than half are in the hands and feet in running legs and feet take up to five 5,000 lb of pressure per square in and in some athletic events like jumping pressure is estimated at up to 20,000 lb per square [Music] in the unique engineering design of the human body reaches its apex in the hand powerful and precise servant of the Mind creator of civilization and culture 25 joints give it 58 distinctly different motions and make it the most versatile instrument on Earth [Music] [Applause] [Music] [Laughter] [Music] we have barely begun to understand the potential of the human brain control center of the incredible machine and the most complex of all living organs how for example to account for hypnosis or the seemingly bizarre Feats of exotic Eastern disciplines subjects have learned to identify and control different types of electrical waves emanating from the brain electrodes picking up brain electrical activity are connected to an electroen holograph an EEG machine which in turn regulates flow of current to a toy train when the brain emits waves of a specific frequency alpha waves in the case of this subject the train moves the larger the alpha wave emitted the faster it goes the implications are vast almost Limitless controlling one's own mind and Consciousness controlling or coping with emotional disturbances all of these May one day be within man's grasp and that day May soon be at hand in the words of Joseph Conrad the mind of man is capable of anything because everything is in it all the past as well as all the [Music] future mentally and physically the human of today is capable of Feats that his primitive forbears could never have imagined [Music] what a piece of work is a man wrote Shakespeare in form in moving how Express and admirable in action how like an angel the beauty of the world the Paragon of animals