Human Growth

so in this car the harris has a special style when a boy reached out oh finished with that before george you dreamed about indian boys why don't you grow up stay up listen i'm just as strong as you are even if you are older tonight let's go yes thank you she said all right i suppose if she said you're a genius believer yes i would not sure i think josie's right is leading this baker she's a blue teacher and i'm lovely i'll keep the school wider years old children in the child you shouldn't want to close it off the way your brain causes experience with considered disadvantage about have you decided what you're going to say i'm going to tell you that the most important thing to look for the changes that take place in our bodies when we grow up go on that is when we become young men and women also shows how growth begins and the changes that take place even before we are born that's right garcia the grandmother to see shows the earliest phases of growth as well as the changes that occur during childhood and adolescence now this motion picture was selected to give you an understanding of the way recycled human growth is repeated over and over from generation to generation has anyone else on the video committee anything to add one i have a loose advice to look for the committee's work down sign lauren will you read them to us please would you talk anymore does human growth began how much does one grow before birth do boys and girls grow at the same rate foot are the names of changes that occur an adolescent boys and girls adolescent is a word we used before who can tell us what it means jenny how if boys and girls just beginning to mature it happens when they're about our age i'm submit you will come tomorrow now i think we're all ready for the film remember the most reactive to the question on the board call sexy yes mr speaker do you think whenever we talk about growth we usually think of growing up but the long road of growth is not just us if it were it would mean that this little baby would someday look like this or that this man once looked like this now let's see how human beings really grow here are two average babies a little boy and a little girl in the course of a few years they will grow to maturity during the first three years growth is very rapid the boy and girl become twice as tall and three times as heavy as they were at first by the age of six more height weight and fanatic notice the boy is a little bigger than the girl at nine arms legs and trunks have become long and slender giving the body a slim appearance about this time the girl begins to grow faster than the boy by 12 or 13 the girl is taller and heavier than the boy and she looks more mature at 15 the girl's growth slows down while a boy keeps on growing at a rapid rate for another year or two when they reach their late teens or early 20s they are fully mature people but the boy again being appreciably larger than the girl by comparing the adult with the child we can see the growth changes more clearly notice that the adult face and head are less rough and the arms legs and trunk relatively longer the boy's shoulders are broader and his body more muscular and the girl's body is more curved and feminine thus we see that growth is more than just growing up the form of the body changes as well growth is controlled by tiny organs within our bodies called glands one of the most important of these is the pituitary gland located in the head it secretes chemicals into our blood the chemicals are called hormones and they regulate body growth the pituitary hormones also influence the secretions of other glands notably with testes and ovaries located in the pubic region of the body the testes secrete the male sex forehand and the ovary is the female sex hormone presence of the male hormone in the blood causes whiskers to appear on the face and hair to grow under the arms in the pubic region and elsewhere on the body the vocal cords get larger and the voice deepens a little the female sex hormone also causes hair to grow under the arms and in the pubic region the breasts begin to develop and the girl's voice deepens a little too these physical changes usually make the boy feel more manly and the girl more woman which are perfectly normal feelings in addition to hormones the testes and ovaries produce the male and female sex cells in which we all have our beginnings the male cell or sperm cell is so small it can be seen only under a microscope when we magnify the sperm cell many times we see the head which contains the nucleus and the trim-like tail which wiggles and causes the cell to move the female cell or ovum while larger than the sperm is still no bigger than a pin point by enlarging the oven many times we can see the cell wall and the dislike nucleus it is from the union of sperm and ovum from father and mother his growth begins the nucleus of the sex cell carries the substance which enables a child to resemble his parents when a boy is between the age of 13 and 16 the testes begin to produce sperm cells at certain times the sperm cells pass from the testes through the tubes and out the penis this happens during mating and sometimes during sleep it is the normal function of the body in addition to the ovaries the sex organs of the girl consist of the tubes the uterus and the vagina when a girl is between the age of 12 and 15 the ovaries begin to produce ova or egg cells about once everyone an oval brightens and leaves the ovary moving into the tube while the omon moves slowly along the tube the uterus becomes virtually supplied with blood to nourish the egg but if the album doesn't meet a sperm cell it fails to grow instead it disintegrates the uterus sheds its leg and the little blood passes from the body the bleeding decreases and in a few days stops completely this process is called menstruation the whole cycle begins again with another overflight usually in the opposite ovaries during early adolescence the natural cycle may be quite irregular it usually takes a year or two for a rhythm to become established these functions begin as we attain sexual maturity but all of us do not mature at the same age these boys and girls for example are all 13 years old yet among them we can see many differences in size and maturity by the time they reach their late teens or early 20s when they have completed their education have a steady job want to get married and are ready to accept the responsibility of having and raising children the differences in sexual maturity will have disappeared human growth can begin only when the sperm cells of the father during mating paths from the penis into the vagina of the mother the sperm cells use their tread-like tails to move into the uterus and cubes if the sperm cells meet an open and once sperm succeeds in breaking through the cell wall fertilization occurs the nucleus of the sperm joins with the nucleus of the oval and growth begins the fertilized ovum begins to divide into many cells while whooping along the tube toward the uterus barely attaches itself to the inner lining drawing its nourishment from the blood of the mother it continues to grow and in a month looks like this at two months it is much bigger and is already beginning to look like a baby you can see the cord which connects the baby to its mother and through which the baby receives its food one of the most wonderful things about nature is that the uterus which is normally not much bigger than the fist is muscular and elastic enough to expand to many times its normal size at four months you can already see why this expansion is necessary the baby now has arms and legs that move inside the mother by six months the baby is gradually turned and moved to this head down position in preparation for birth the baby is very active now it is not only the uterus that expands to accommodate the growing baby here you can see how the whole abdominal wall stretches this baby has developed for nine months and is about to be born if the mother were lying down this would be the position of the baby just before birth you would see the mother's spine below the enlarged uterus the head settles to a lower position and the muscles of the uterus begin to force the baby out the muscle walls of the vagina expand to make room and the baby's head begins to move out of the mother the doctor lends a helping hand and the new baby meets the outside world since the baby no longer have to depend upon its mother's blood for food the doctor ties and cuts the cord the baby cannot feel the cutting any more than you can feel it when a barber cuts your hair ruth continues and this baby will become a full-grown boy or girl and eventually a father or brother thus continuing the cycle of killing [Music] growth [Music] so [Music] the principles of growth the development of rejecting in this cell upon all human should start our beings by answering the first of the questions on the board who can tell us where truman growth begins how growth begins from the spring cellars and egg cells [Music] do you have a question uh i guess it's kind of a silly question the only silly question and the one that is not your questions help you to learn they also help me to teach well i was wondering why there are so many sperm cells and only one egg cell that's a very distrusting white it's the point that doesn't know what's happening itself thank you for flying to explain it more fully six it's time eleven would you project it please let's pretend for a moment that there is only one firm cell the openly produced hair and moves into the tube the springtail has to travel all the way up here to find the oven most of the time the two sets out wouldn't need at all and very few babies will be born that's the reason for having more than one sperm in addition it takes many stone cells striking against the oven to weaken the cell wall so that one sperm can enter and the knife is the nucleus of the organ so nature doesn't depend on just one first cell she provides millions of them any one of which might further rise beyond them should that answer your question boys yes it does miss baker are there any more questions julie about menstruation is it really normal for the body to bleed like their completely normal jewelry essentially because they should plant it that way remember in the animated film the lining of the uterus became problems blood with wish and nourish and fertilize over here well when the oil does not fertilize there's no need for this nourishment so the uterus nearly shares a single line and naturally a little blood leaves the body at the same time now for the questions the recipes you have perhaps you should ask them in turn then we can organize our discussion around them as one of those on the board do you boycott anything like meditation i heard another tell a neighbor i was working there and what does that mean why don't people have red hair how long will it take for my voice to change how girls bigger than boys that charles is 13. everybody should rather fight himself suddenly to look like her with my little lacquer only those questions questions