Humans_Concept_3
Human reproduction
Human reproduction
Children's awareness of reproduction, birth and growth. Not long after the birth of the first child in my class, I noted that three of the eight reception children at my school had mothers who were pregnant. After some careful, roundabout questioning, all three acknowledged that their mothers had babies in their tummies'. When asked how the baby would get out, one child said that Mum was going into hospital to have it removed. Another told me about a 'special hole' between Mum's legs. The third child burst into tears, clearly having worried about the problem for some time: Mum's tummy kept getting bigger and there was no way that the baby would fit through her belly button, heaving only one option — Mum was going to explode! (A number of mothers whom have since regaled with this anecdote have said: The third kids not far wrong'.) A brief chat with the mother concerned helped me to realise how unaware many parents assume their children to be, and how difficult they can find it to talk to their children about *certain things'.
By approaching reproduction and growth from this starting point, you are focusing on an event of immediate interest to a large number of children. In my experience, children aged three to five show surprisingly little interest in how a baby 'gets in there] so discussion can focus on birth and the first year or so of life,
The explanation that 'there's a special hole between Mum's legs', is usually sufficient to explain how the baby will be born — but the addition of 'When it's ready, it will start pushing so Mum will know' is usually wise, or you might have children worrying even more! You can also rely on the knowledge of other children to further the discussion — 'Mum said I was born in the middle of Tesco'; 'My Mum had an operation when my little sister was born'; and so on. These anecdotes can be used to further the discussion, with the children explaining and you correcting where necessary.
A new baby's needs are often difficult for an older child to come to terms with, especially when they haven't shared their parent(s) before. If you can persuade a mother (or father) to bring their new arrival into school for a group of children to look at, and to answer questions about what the baby does and needs, the experience can be enlightening for all concerned. My personal favourite was a question put to the mother of a three-month-old baby: Does he eat crisps?' 'No, I'm still feeding him.' 'What flavour crisps are you feeding him then? Young children are often quite surprised by the helplessness of babies and the constant care and attention that they require. (This is a very telling point to make with twelve- to fourteen-year-olds as well!) Sleeping and feeding patterns are quite important to the children, as the situation may be seen as 'unfair' — 'He's only a baby, but I have to go to bed before him'; 'She eats all the time, but I have to wait for tea', By talking these points through, the children can come to a better understanding of a babies needs and a greater sense of shared responsibility.
By the end of KS I children can begin to look back over their lives and identify key developmental points: walking, speaking, starting school, reading riding a bike. They can begin to associate 'growing up' with themselves by noting things that they are now able to do but couldn't do before. There may be an awareness of changes in their own bodies: more balance, greater control, different proportions. They are also likely to become more aware of differences between their own and other children's bodies: gender overall size and shape, colour, physical abilities. The idea that everyone is built to the same basic design, but that each person is unique can be developed from here.
By KS2, children are becoming more aware of themselves as individuals. This self-consciousness may lead them to exaggerate the differences between themselves and others, with either positive or negative results. Rates of growth begin to be an issue: some children may be growing faster than others, and some parts may be growing faster than others. There may be considerable concern about what is 'normal' — and between eight and eighteen, this has to be tackled very broadly from physical, social and emotional perspectives. It is impossible to deal with all of these issues from a scientific or teaching point of view here; and many are also subject to particular religious factors. As a former teacher of this age group, I would stress the importance of teaching the physical in the context of emotional and social considerations, and emphasising the importance of a stable family situation (whatever form the family unit might take),
During KS2, as well as looking back, children should be looking into their dim and distant future: adulthood The changes undergone between childhood and adulthood are significant — not only physical changes, but emotional ones with new levels of responsibility. Children should begin to compare themselves not only with young adults (18—35), but also with middle-aged adults (35—55) and those in old age. (See illustration above.) Expectations about physical and emotional changes should be identified and considered Although all of these points are relative, and subject to considerable bias and stereotyping, the differences considered might include physical strength and stamina; suppleness and flexibility; mental agility and concentration; and long- and short-term memory.
Although at the primary level children should know the names of specific body parts, this must be regarded only as a first step, Having a common vocabulary as a basis for
communication will enable children to develop an understanding of each named body part, including how it works and the purpose that it serves.
Since this is a purely vocabulary-based topic, we can move on directly to consider teaching ideas,
Human reproduction
Males, from a purely physical point of view, are usually capable of taking part in reproductive activity from the point that they reach maturity until they die. Male reproductive maturity is not usually achieved before the age often or eleven, and will depend on nutrition and hereditary factors. Sperm, the male contribution to sexual reproduction, are continually produced in the testes, which are suspended in a sac called the scrotum to keep them a couple of degrees Celsius below normal body temperature. The sperm are mixed with a watery fluid to produce semen, which is retained within the body until it is ejaculated through the penis, This may happen unconsciously during sleep or as a direct result of stimulation. There are something like 300 million sperm in each ejaculation.
Once the sperm have been delivered to the passage leading to the organ that contains the female eggs, the male role in reproduction (from a purely genetic perspective) has been completed. Although males are capable of producing sperm throughout their lives, there is recent evidence that the sperm count declines in later years (anything less than 5 million per ejaculation is classed as sub-fertile) and that sperm produced by older men have a greater proportion of genetic defects.
Females are born with a fixed number of eggs. These are released in a regular cycle of approximately one per month, starting soon after reaching maturity and ending when hormonal changes cause it to cease (some time between the mid-forties and the mid-fifties). In a 28-day cycle, the first five days will consist of the breakdown and release of the lining of the uterus, which wilt flow out of the vaginal passage. During days 6 to 1 3, the lining of the uterus is renewed and thickened with a rich blood covering. Hormonal signals then trigger ovulation: the release of a mature egg or ovum from the ovarian sacs. During days 15 to 28, the egg floats down the fallopian tube and enters the uterus.
If a sperm impregnates the egg during this period, the fertilised ovum will attach itself to the wall of the uterus, where it will begin to grow into an embryo. Hormonal changes will cause the growth of the placenta, through which the embryo will derive nourishment. If a sperm does not impregnate the egg, or the ovum does not attach to the lining of the uterus, the lack of hormonal signals will prevent the lining of the uterus from developing further, and it will be discarded at the start of the next cycle.
The rate of growth, starting with a single impregnated egg cell, is very impressive. By about five weeks, the embryo is just big enough to be seen; it has specialised cell growth, so that the body, head and internal organs have all begun to develop. After eight weeks, it is recognisable as something vaguely animal-like, with arms, legs and eyes — it is now called a foetus. At 12 weeks, it is moving around and has become recognisably male or female. By 1 6 weeks, it is about 15cm long and has begun to stretch the uterus. Eight weeks Eater, it will have doubled in size and will have periods of activity and rest; it now responds to sounds from outside the mother's body. During the last month in the uterus, the baby will practise doing useful things such as sucking its thumb and will put on some body fat.
The mother, through the umbilical cord, provides all the nourishment and oxygen that the baby needs, and takes away all of the waste products. This dependency continues until birth (though some mothers claim that it continues until at least the mid-twenties). The uterus, which at the start of pregnancy was about the size of a small pear, ends up just prior to birth as big as a basketball. During birth, the muscular walls of the uterus contract to ease the baby out.
Once a human reaches full sexual maturity there is a phase — generally between 8 and 35, although this will depend on many factors, including genetics, nutrition and general health and fitness — in which the body reaches a peak of performance. Beyond this, there is a steady decline as parts of the body begin to wear out and repair is less effective. There are only so many times that cells within the body can successfully divide in order to replace lost cells. Genetic errors begin to creep in, and the body begins to age, Beyond the age of 55 or so, irreversible changes will have begun to take place: female reproduction may no longer be possible, joints may have begun to degenerate, and skin will be less flexible. If the cells could be made to continue dividing for longer, the incidence of cellular degradation would be reduced and the effects of ageing delayed.
Children can become very concerned about birth and the early stages of development, especially when it is happening in their family It is quite likely that children will gain siblings while they are aged between three and five — and if they are not adequately prepared, this can become quite a traumatic event in their young lives. Appropriate education can help them to understand the changes in mother and baby, and the changes at other points in their own physical development and maturation,
From the teacher's perspective, it is a matter of choosing the right time and vocabulary to talk these things through with the children. Any discussions of this kind should be carried out in accordance with your school's policy on sex education. Parents should at least be pre-warned; at best, they should be involved in detailed discussion of the intended programme. Because of these complexities, this section focuses on the likely misconceptions and pedagogical issues as well as the biological facts.
Vocabulary
Embryo — the early stage of development of the fertilised ovum.
Foetus — the later, distinctively human phase of development of the embryo leading up to birth.
Ovum — the egg; the female contribution to reproduction.
Placenta — a growth within the uterus that provides the foetus with its blood supply.
Sexual reproduction — the combining of genetic material from two individuals to produce a new life.
Sperm — a mobile cell which contains the male contribution to reproduction.
Uterus — a special organ in the female abdomen which provides an environment for the developing embryo and foetus
Human females seldom have more than 400 to 450 fertile periods (each lasting 24 to 48 hours) in their lifetime, whereas the average contents of one male ejaculation provides sufficient sperm to replace the population of most ofWestern Europe.
Most studies show that the ratio of mate to female centenarians varies from 1 in 4 to 1 in 7,
Misconceptions from parents:
Sex education is all about conception and contraception.
During the later pre-teens and teens, this will probably be the case; but parents of younger children must be reassured that this content is not the entirety of the subject Teachers need to take parents carefully through the potential lines of development that the topic will take during KS' and KS2, If teaching reveals that a child has knowledge concerning sexual practices well beyond the expectations for that age, the teacher and headteacher will need to consider carefully where the child obtained that knowledge.
Misconceptions from children:
Babies can't talk because they have small brains. Humans are born with some abilities and have to learn others. Babies are born with the ability to make a noise, but it takes time for them to learn how to communicate with words. it has nothing to do with brain size: it has to do with the amount of time that it takes to learn a complex new skill.
Questions asked by adults:
Do I have to teach sex education?
The absolute answer is probably no — but this question may indicate a misconception about what is supposed to be taught. A surprisingly large amount of the early 'sex education' content can be taught through the general class ethos — relationships, caring for others — and through discussion rather than through explicit factual teaching. Please refer to school policies and government guidance.
Can I withdraw my child from sex education lessons?
Technically, yes — but are the parents clear about what they are actually withdrawing their child from? It is likely that this question indicates a misconception about what the content will be. Also, given that the teaching in question is likely to be embedded in general class sessions rather than in neatly packaged 'sex education lessons', withdrawal of a child may present practical problems.
Questions asked by children:
My mum has just had twins — how did two babies get in there?
Sometimes two (or more) eggs are released at the same time and, if fertilised, they both grow into babies. These will be non-identical twins, because they have come from different eggs. Sometimes a single egg very soon after it begins to grow into a baby, splits into two and both parts grow into babies. When this happens, the twins will be identical: they will look almost exactly the same
Interviews (questioning, researching)
Ask the children to devise questions to ask a mother with a young baby about the baby's physical and mental abilities, Can they devise similar questions to ask a middle-aged person and an elderly person about themselves? Clearly, some editorial control will be required; but the key is for the children to identify the changes, and to note similarities and differences with their own circumstances. Invite appropriate people in, and conduct class or group interviews.
Age collage (classifying, observing)
The children can cut out and mount photographs of people of different ages, either in sequential order or in sets to represent different age groups. in the latter case, discuss with the class what these age groups should be,
Can do/can't do (observing, matching)
Make a class list of things that humans of various ages are able to do: go to the toilet themselves, feed themselves, walk have children and so on. Link these statements to magazine photos of different-aged people. The effects of old age will need to be discussed with the class, as abilities can vary greatly: an elderly relative who is fit and active Wilf need to be considered at the same time as a more senile elderly relative.
Timeline (sequencing, recording)
The children can produce their own personal timelines, incorporating photographs and key dates (which do not need to be exact) relating to their own physical development — for example, when they first walked, talked or rode a bike. This activity could be extended by using scanned images to produce a computer presentation; the file could be developed into a web page with hyperlinked pages containing greater detail.