Can Kissing Make You Live Longer? Body and Behaviour Mysteries: Explaine d Oddball Questions

By Stephen Juan

The mysteries of our weird bodies explained.
Body and behaviour mysteries explained. Can kissing make you live longer, even help prevent a food allergy? Does reading about yawning make you yawn? Can picking your nose kill you? Will garlic breath make you sexy? And why do men and women 
doodle differently? In the latest book from Dr Stephen Juan - Australia's award-winning WIZARD OF ODD - you'll find curious mysteries and strange facts about our body and behaviour. From thunder headaches and burping corpses to 'confessing Sams' and 'secret keepers', Stephen Juan's explanations will fascinate and entertain you.

• Language: English
• Publisher: HarperCollins Publishers Australia
• Release date: Jun 1, 2010
• ISBN: 9780730445890

Stephen Juan

Dr Stephen Juan is an anthropologist and educator who is best known for his award-winning newspaper and magazine articles and for his TV and radio presentations. Dr Juan grew up in California and for more than 30 years has taught at the University of Sydney where he is the Ashley Montagu Fellow in the Faculty of Education and Social Work. This is the seventh book he has written published by HarperCollins Australia.

Book preview

To the many readers who have asked questions

Table of Contents

Cover Page

Dedication

Introduction

Chapter 1 Beginnings

Chapter 2 The Head

Chapter 3 The Eyes

Chapter 4 The Nose

Chapter 5 The Ears

Chapter 6 The Mouth

Chapter 7 The Skin

Chapter 8 The Hair & Nails

Chapter 9 The Skeleton, Bones & Teeth

Chapter 10 The Heart, Blood & Lungs

Chapter 11 The Stomach & Intestines

Chapter 12 Otherwise Inside

Chapter 13 Behaviour

Chapter 14 Endings

Afterword

References

Index

About the Author

Acknowledgements

Copyright

Introduction

Greetings, reader!

Welcome to my latest book, packed full of lots of curious and strange facts and information about our fascinating human body. No doubt there will be something to interest everybody, or should I say every body?

For starters, find out why fewer boy babies are born during hard times, why ‘morning sickness’ is necessary during pregnancy, and the difference between a chromosome and a gene (Chapter 1). Find out what a ‘brain freeze’ is and why it hurts so much (Chapter 2), how far the naked eye can see (Chapter 3), and why pepper makes you sneeze (Chapter 4). Discover if our ears grow longer with age (Chapter 5), if it is possible to get a food allergy by kissing someone (Chapter 6), and what manner and number of microscopic life live on the surface of the human body (Chapter 7). Learn why we are actually not ‘naked’ while in our mother’s womb (Chapter 8), why some people cannot stop tapping their toes (Chapter 9), and what shape the human heart really most resembles (Chapter 10). Look into why opera singers are usually fat (Chapter 11), whether the human body generates light (Chapter 12), and if there is a limit to the number of times you can almost die and be brought back to life (Chapter 14).

And if all this doesn’t arouse your interest, then there’s a special chapter on human behaviour (Chapter 13). Of course it is purely coincidental that the behaviour chapter is number 13 and has nothing to do with anyone suffering from triskaidekaphobia (an irrational fear of the number 13). Chapter 13 explores topics such as why so many people believe in conspiracy theories, why so many gamble, and why some people are more accident prone than others. It’s also quite curious to know why some people confess to crimes they did not commit, if lie detector tests really work, and why humans so often doodle, and much, much more.

There are probably many other intriguing topics not yet discussed, but we will hopefully get around to all of them eventually—quite a task! In the meantime, enjoy this latest offering.

Chapter 1

Beginnings

WHAT MAKES A HOMO SAPIEN A HOMO SAPIEN?

(Asked by Ralph Turner of Bangor, Maine, USA)

All forms of life, from the simplest to the most complicated, are classified scientifically into a system known as taxonomy. As humans we are Homo sapiens—we are animal, mammal and primate in one. According to the classic taxonomic system developed by Swedish biologist Carl Linnaeus (1707–1778), and added to by many others since, humans are classified into: domain, kingdom, phylum, class, order, superfamily, family, genus and species. Although some authorities dispute various aspects of what appears below and have even proposed additional categories, humans are taxonomically humans due to the following:

• Domain: Eukaryota. We are classified among organisms with a complex cell or cells and with genetic material that is organised into a membrane-enclosed nucleus or nuclei.

• Kingdom: Animalia. We are classified among organisms that are multi-cellular, capable of locomotion and feeding themselves via other organisms or parts of other organisms, and those that develop a stable body structure.

• Phylum: Chordata. We are classified among the vertebrates (those animals with a type of spinal cord) or closely related and complicated invertebrates. Chordates have a notochord which is a flexible, rod-shaped body form in embryos. In lower vertebrates it continues throughout life. In higher vertebrates it becomes a vertebral column. Chordates have a dorsal nerve cord which later becomes the brain and spinal cord. It is formed from a part of the ectoderm that rolls and forms a hollow tube. Chordates have pharyngeal slits used for feeding. In primitive chordates the pharyngeal slits strain water and filter food particles. In more advanced chordates the pharyngeal slits disappear at the embryo stage. Chordates have an endostyle which is a groove on the ventral wall of the pharynx that produces mucus used in eating. Chordates have pharyngeal pouches which are also used for feeding. These become gills in fish. Chordates also have a tail. In our case we have only vestigial evidence of this.

• Class: Mammalia. We are classified among the vertebrate animals that have: mammary glands that produce milk; hair or fur; specialised teeth; three small bones in the ear; a neocortex region in the brain; ‘warm-blooded’ bodies; a four-chambered heart; and a brain-regulated circulation and temperature-controlling system.

• Order: Primate. From the Latin word primus meaning ‘first’, we are classified among the prosimians that most closely resemble the early proto-primates (such as lemurs), the ‘monkeys of the New World’ (such as capuchin monkeys), and the ‘monkeys of the Old World’ (such as baboons).

• Superfamily: Hominoid. We are classified among the non-human-like primates, that is, the great apes—chimpanzees, gorillas and orang-utans.

• Family: Hominidae. We are classified among the human-like primates both extinct and still in existence.

• Genus: Homo. With the Latin homo meaning ‘man’ or ‘human’ in its more recent meaning, we are classified among modern humans and our close now extinct relatives. Homo erectus (upright human), Homo neanderthalis (Neanderthal human), Homo habilis (tool-making human), Homo floresiensis (flower human) and others.

• Species: Sapiens. With the Latin sapiens meaning ‘wise’, we are Homo sapiens (wise humans). Some argue that Homo sapiens idaltu (elder wise humans) is of our species, too, although also now extinct; others argue that we should be rightly classified as Homo sapiens sapiens to make clear this last distinction.

WHAT IS THE NEXT STEP IN HUMAN EVOLUTION FOR HOMO SAPIENS?

(Asked by Ralph Turner of Bangor, Maine, USA)

It is anyone’s guess as to what will be the next step in the evolution of Homo sapiens. Nature has been working on the model for more than 3 million years through natural selection. Some scientists have speculated that the next adaptive changes to humans may be to the anatomical structure with better spine, ears, eyes, hips, joints, etc. or perhaps it will be changes in our brain or in our consciousness that will usher in the next subspecies. Homo sapiens humanus (as opposed to Homo sapiens non-humanus) would be a modern human who is humane, cultured, refined, educated, compassionate, empathetic, creative, intuitive, courageous, spiritual, generous and energetic. (An ideal dinner party guest?) They would be teachers, healers, helpers, creators, preparers, nurturers, transformers and repairers. (Pretty handy to have around, right?) They would see something and want to make it better, and think of others not just of themselves. They would understand the most important philosophical principle of human awareness: that the greatest receiving comes from the greatest giving. Our body, brain and consciousness would evolve together. For example, we now know that experience during the early years of human development has effects on brain structure, particularly in the frontal lobe region responsible for empathy. This in turn affects changes in human behaviour. Those receiving a humanus experience will develop more advanced brains than those receiving a non-humanus experience. Such advancement would be passed on from offspring down to another and so on in the lineage. Perhaps through our more enlightened behaviour we could influence our own evolution?

HOW WAS PATERNITY DETERMINED BEFORE WE HAD DNA ANALYSIS?

(Asked by Shawn Joseph of Rockdale, New South Wales)

Before DNA analysis, paternity was established by comparing inherited characteristics of blood cells from the father, mother and child. For example, the membranes of white blood cells contain surface proteins known as antigens. People who are not related almost never have the same type of antigen. So the most accurate paternity tests used antigens on white blood cells called leucocytes. On average, using this test ruled out 90 per cent or more of men as a child’s father. Other tests could be performed on the antigens and internal proteins of the red blood cells and the proteins in plasma, the clear part of the blood. A thorough paternity test consisted of some 34 different tests that together were about 99.6 per cent accurate. If a man was not excluded through these tests, the probability of paternity was calculated by comparing the likelihood that the child inherited shared characteristics from him rather than from an unrelated, unknown man of the same ethnic background. If the probability was above 90 per cent, then most courts held that the man was the child’s father.¹

WHEN DID HUMANS FIRST START GIVING BIRTH BY CAESAREAN?

(Asked by Rene Bernard of Vancouver, British Columbia, Canada)

Ancient Egyptian folklore contains references to Caesarean section (CS) deliveries going back about 5000 years. Throughout most of history, CS was performed only as a last resort and to save the baby from a dying mother. The mother did almost always die. CS was so dangerous that the mother probably considered herself lucky if she and her baby survived, even if she was rendered infertile, which also often happened.

The popular belief exists that the Roman emperor Julius Caesar was born by CS and gave his name to it. But this is unlikely. Aurelia, Caesar’s mother, survived. This is unusual in itself. Also, under Roman law at the time, CS would not have been performed on her. Of course those attending her may have decided to ignore the law to save the mother and baby. Later, the Roman law governing CS known as lex regia was changed to lex caesarea under subsequent Roman emperors. This is probably how the name came about.

It was not until the 16th century that the first case of a woman giving birth by CS and surviving was verified. However, if Aurelia did give birth by CS, it is even more remarkable since she gave birth to further children. Ironically, under Roman law, the mother’s husband performed the surgery. In that sense Caesar would have been fortunate. His father was a swineherd. Swineherds often have experience performing similar surgery on pigs. In England and North America, death rates for the mother in CS deliveries were about 75 per cent until the mid-19th century. For the baby, it was only a little better.²

WHY ARE THERE MORE CAESAREAN BIRTHS NOW?

(Asked by Rene Bernard of Vancouver, British Columbia, Canada)

Although CS is major abdominal surgery, it is generally regarded as being safer now than at any other time in our history. This is due to overcoming post-operative complications including the ability to fight infections. Prolonged labour and risks to both mother and baby places pressure on childbirth professionals to act quickly. Statistically, in the English-speaking world, women are waiting until later in life to have children. As a consequence, more women experience natural childbirth difficulties due to causes not entirely understood. CS deliveries far exceed the estimated 12 per cent incidence of need. Yet in some areas of the English-speaking world, the CS figure is 30 per cent or more. Beyond this, in Brazil CS delivery is regarded as the preferred form of delivery and is taught so in medical schools. A team of US doctors in California argues that the recent assertion of ‘a woman’s right to choose’ is a major factor in ‘CS or no CS’.³

The most foetuses found in a human body was 15. This included 10 girls and 5 boys. They were 4 months old when they were removed from the womb of an Italian housewife in July 1971. The woman had been taking a fertility drug.

Thanks to the twisting and cramped interior of the birth canal, human babies, unlike those of other primates, tend to turn mid-birth and exit the vagina facing downwards.

The World Health Organization estimates that worldwide 15 per cent of childbirth labours have a life-threatening complication.

It has been estimated that the ‘natural’ rate of maternal death from childbirth is between 1 and 1.5 per cent. The biggest risk is uncontrolled bleeding.

HAS MUTILATING THE BODIES OF CHILDREN EXISTED IN ALL SOCIETIES THROUGHOUT HISTORY?

(Asked by Miguel Padilla of Mexico City, Mexico)

If not all, then certainly most societies have routinely mutilated the bodies of children. Of course this depends on what one considers as ‘mutilation’. For example, the practice of circumcision is thought of as mutilation by some people yet not by others. If we define it broadly, then mutilation of children’s bodies in some form or another is found in nearly all cultures throughout history. For instance, the prehistoric middle Palaeolithic period began some 300,000 years ago. Palaeo is Greek for ‘old’ and lithos is Greek for ‘stone’, hence ‘stone age’. Palaeolithic cave paintings show children’s hand prints often with fingers missing. It is believed that children had their fingers cut off in the widespread belief by many cultures that animal spirits demanded a child’s finger to appease them. Finger sacrifice rituals have been found in many cultures as have places where amputated fingers were stored.⁴, ⁵

HOW DO WE DEFINE ‘RACE’?

(Asked by Sean Scully of Riverview, New Brunswick, Canada)

A way of thinking about ‘race’ is to define it as including all members of any human group that can successfully breed with each other. A ‘race’ includes all the descendants of a common human ancestor. So it is like a family, a tribe, an ethnic group, a nation, or the entire world’s human population. This is the broadest biologically defensible definition. ‘Race’, as it is commonly understood (and misunderstood) is a social construct rather than a biological one. It is impossible to scientifically define as distinct a human race as apart from another distinct human race on biological criteria alone. There are as many human races as there are human beings due to the genetic uniqueness of each of us. The only possible exception to this would be identical twins, where the number of members of that race would be exactly two!

There are genetic-based outcomes among populations living in specific geographical areas that can set them off from populations in other geographical areas. These outcomes may make certain populations more or less susceptible to having specific anatomical features or health conditions. There may be a survival advantage favouring a particular feature in a certain environment. For instance, more prominent eyelid folds among the Inupiak people of the Arctic may help protect them against snow blindness. Such an anatomical feature would be of no advantage in a snow-free environment. Tay-Sachs disease, a genetic-based disease causing mental and physical deterioration and often death by age 4, is more prominent among Eastern European Jews. Sickle Cell Anaemia, a disease affecting red blood cells that results in early death (often by age 40), is more prominent among sub-Saharan Africans.

The rate of giving birth to twins varies with geography. West Africa has the highest birth rate of twins in the world. For example, the Igbo-Ora of Nigeria have 31.6 twin births per 200 live births compared to an average of 1 twin birth per 200 live births in European nations.

The fact that all anatomical features or health conditions differ among human populations proves only that there is variation everywhere on Earth. But to define any one population as a ‘race’ as apart from another population as another ‘race’ is to divide people on a crude and misleading basis. Such a judgment invites bias and prejudice.

‘Race’ has been given great prominence in Western history, particularly over the last 600 years with the advent of New World exploration, the contact of Europeans with non-Europeans, and European empire building. ‘Race’ has often been the ill-conceived basis for the most terrible discriminatory policies, laws, social movements, ethnic cleansings and wars in the long and sorry history of man’s inhumanity to man. ‘Race’ is today a scientifically and socially bankrupt concept.⁶

There is a 1 in 200 chance that a male human worldwide is a direct patrilineal descendant of Genghis Khan.

The man with the oldest known individual ancestor is British professor Adrian Targett. DNA tests matched Professor Targett’s with that of a 9000-year-old skeleton found in Cheddar, England.

The oldest authenticated pair of female twins was Kim Narita and Gin Kanie of Japan. They were born on 1 August 1892. Kim died of heart failure in January 2000 at 107 years of age.

The longest living triplets were Faith, Hope and Charity, who were born in Elm Mott, Texas, on 18 May 1899. Faith was the first to die at age 95 in October 1994.

The world’s oldest quadruplets were the Ottman siblings—Adolf, Anne-Marie, Emma and Elisabeth. They were born on 5 May 1912. Adolf died first at age 79 in March 1992.

CAN AN EXTINCT HUMAN LIKE A NEANDERTHAL MAN BE CLONED AND BROUGHT BACK TO LIFE?

(Asked by Ken Alvarez of Shreveport, Louisiana, USA)

Theoretically, this is certainly possible, but there would be technical problems along the way in trying to do it. There are also many ethical and moral issues to be resolved satisfactorily beforehand. After all of this, the steps for cloning a Neanderthal would be similar to the following:

1. Obtain a reliable DNA (deoxyribonucleic acid) sample. A thorough search is required for cells from the to-be-cloned Neanderthal, including bone and teeth cells. Neanderthal hair and skin cells could be used if available, but since hair and skin make poor fossils compared with bones and teeth, none survive for the Neanderthal. Extracting healthy DNA fragments from the nucleus of cells of Neanderthal bones and teeth would be very difficult to do.

2. Rebuild the genome. The broken DNA of the Neanderthal is reassembled using the genome of a related living human as a guide.

3. Swapping DNA. Eggs from the ovaries of a living human are removed and their nuclei replaced with the restored genetic material from the Neanderthal.

4. Stimulating the eggs. Genetically engineered restructured eggs are treated with chemicals or perhaps electric current to fuse the nuclei with the eggs and trigger cell division.

5. Implanting the embryo. After the desired cell division has started and progressed to form an embryo of about 200 cells, the embryo is implanted into the womb of a living woman where it is carried to full term like any other human embryo.

6. Birth. The surrogate mother gives birth to the Neanderthal baby in a normal human birth, and the baby will grow up into a Neanderthal adult.⁷, ⁸, ,⁹

WHAT IS THE DIFFERENCE BETWEEN A GENE AND A CHROMOSOME?

(Asked by Lynn Davis of Casper, Wyoming, USA)

All life is made up of cells. All cells in the human body, except red blood cells, contain chromosomes. Chromosome comes from the Greek khroma meaning ‘colour’ and soma meaning ‘body’. Chromosomes got their name from the first lab experiments in the 1880s where it was revealed that chromosomes could be stained with dyes, making them easier to study.

A gene is located on a chromosome. Every factor in inheritance is due to a particular gene. Genes specify the structure of particular proteins that make up each cell. Gene comes from the Greek genea meaning ‘generation’, ‘origin’, ‘beginning’, ‘kin’ or sometimes ‘race’. Gene was shortened from ‘pangene’ which means ‘all-generation’. Genes contain DNA, the chemical basis of heredity.

Think of it this way: DNA is in genes, genes are on chromosomes. When it was first seriously conceived to ‘map’ all genes on all human chromosomes, it was called the Human Genome Project—a combination of ‘gene’ and ‘chromosome’.¹⁰

WHAT HAPPENS WHEN A CHROMOSOME IS ABNORMAL?

(Asked by Lynn Davis of Casper, Wyoming, USA)

Each chromosome has a specific and proper structure and colour. Together, all the chromosomes in our body form a distinct pattern called the human karyotype. We have 46 chromosomes (23 from each parent), however there are variations in reproduction due to abnormalities in the karyotype of an individual. A few of these abnormalities are beneficial, most are harmless, and a few are catastrophic. A major chromosome abnormality (MCA) accounts for half of all spontaneous human abortions. An MCA occurs in about 1 in every 100–200 births. Recent medical diagnostic techniques can now detect many MCAs long before the child is born by analysing the patient’s blood under a microscope. MCAs take one of five forms:

1. In duplication, instead of the normal two, the individual has three copies of the chromosome in every cell of their body (trisomic). Most trisomics result in a spontaneous abortion—but not always. Trisomy-21 (Down’s syndrome) occurs 1.5 times in every 1000 births—the individual has three copies of chromosome 21. Trisomy-8 (Edward’s syndrome) occurs 3 times in every 10,000 births—the individual has three copies of chromosome 18. Trisomy-13 (Patau’s syndrome) occurs 2 times in every 10,000 births—the individual has three copies of chromosome 13.

2. In deletion, a piece of chromosome may go missing. The missing piece is usually from the end of the chromosome, but can be missing from the middle as well. The types of symptoms and their severity will vary depending on the size and location of the deletion. Deletion syndromes occur at a frequency of about 1 in every 16,000 births. In Wolf-Hirschhorn syndrome (1 in every 50,000 births) the abnormality occurs on chromosome 4. In Cri du Chat syndrome (1 in every 50,000 births), the abnormality occurs on chromosome 5.

3. In translocation, a whole or a piece of a chromosome becomes attached to another.

4. In inversion, a portion of the chromosome breaks off, turns upside down, and reattaches.

5. In rings, a portion of the chromosome breaks off and forms a circle, with or without loss of genetic information.

In the last three forms, there is an alteration in the pattern of genetic information.¹¹

CAN BRAIN DAMAGE OCCUR IF A BABY IS LEFT TO ‘CRY IT OUT’?

(Asked by Christine Koch of Strathfield, New South Wales)

Research suggests that allowing a baby to ‘cry it out’ can cause brain damage and at best causes extreme distress to the baby. Evidence is mounting that such distress in a newborn blocks the full development of certain areas of the brain and causes the brain to produce extra amounts of cortisol which can be harmful. According to Dr Michael De Bellis,¹² children who suffer early trauma generally develop smaller brains.¹³

Dr Martin Teicher¹⁴ and colleagues claim that the brain areas affected by severe distress are the limbic system, the left hemisphere and the corpus callosum. They note that baby neglect resulted in a 15 to 18 per cent reduction in regions 3, 5 and 7 of the corpus callosum (the connective fissure between the two hemispheres of the brain that facilitates their communication).¹⁵ Additional areas that may be involved are the hippocampus (located in the centre of the brain and vital for long-term memory and spatial perception) and the orbitofrontal cortex (located at the front of the brain and vital for thinking such as decision making).

Dr Margot Sunderland¹⁶ argues that some of the brain-damaging effects may occur if parents fail to properly nurture a baby—and that means not allowing them to ‘cry it out’. Dr Sunderland draws upon her work in neuroscience to come to these conclusions and recommendations about parenting practice. In The Science of Parenting, the first parenting book to link parent behaviour with infant brain development, Dr Sunderland describes how the infant’s brain is still being ‘sculpted’ after birth, and that parents have a major role in the brain ‘sculpting’ process. To do this properly, Dr Sunderland advocates that it is crucial for parents to meet the reasonable emotional needs of their child. This is assisted by continuously providing an emotionally nurturing environment for the child. Allowing a baby to ‘cry it out’ when they are upset will probably be regarded as child abuse by future generations.¹⁷, ¹⁸

WHY IS IT SO HARD TO LET A CRYING BABY CRY?

(Asked by Nikki Ryan of Toowoomba, Queensland)

Research shows that our ‘cry response’ to a child’s cry may be hard wired into our brain. A baby cries because it is hungry, tired, too hot, too cold, lonely or otherwise unhappy. In effect it is the only way the child can communicate their needs. If they could talk, they would. If a baby did not have a terribly shrill cry, they would less likely get attention and, from an evolutionary point of view, would unlikely be responded to and hence perish. So biologically, nature gives a baby their terrible cry for survival purposes. According to Anni Gethin and Beth Macgregor,¹⁹ ‘Parents are too biologically wired to not respond to their babies’ cries; responding isn’t simply a matter of choice, like whether to go see a movie or a band on a Friday night. Magnetic resonance images (MRIs) of mothers’ brains show that the hypothalamus and cingulated (parts of the mammal brain) are activated when their baby cries. The result is that most mothers feel physically compelled to pick up and soothe their crying babies…’²⁰

DO HAPPIER BABIES GROW UP TO BE BETTER LOVERS?

(Asked by Nikki Ryan of Toowoomba, Queensland)

A recent study suggests that happier babies make better romantic partners later in life. Dr Jeffry Simpson²¹ and his team studied a group of 78 babies from age 1 over a period of 25 years. In a series of experiments on ‘attachment’, the Simpson team first noted which babies were more ‘securely attached’ to their mothers (and hence ‘happier’) compared with other babies. Follow-up studies many years later when the babies grew up to around age 20 to 23 years old showed (all other things being equal) that the adults who were more secure as babies had much deeper and overall happier romantic relationships than those who were less secure as babies.

The Simpson team adds that the babies who were more securely attached to their mothers had ‘more secure relationships with close friends at age 16, which ‘in turn predicted more positive daily emotional experiences in their adult romantic relationships (both self- and partner-reported) and less negative effect in conflict resolution and collaborative tasks with their romantic partners (rated by observers).’²²

So how do you get ‘more securely attached babies’? For starters, always pick them up when they cry.

IS AMNIOTIC FLUID SIMPLY URINE?

(Asked by Giulia Rossi of Rome, Italy)

Amniotic fluid is the clear, yellow-brownish liquid that surrounds the unborn baby; it is contained in the amniotic sac. The fluid consists mostly of foetal urine that bathes the developing foetus. The foetus floats in this fluid—warmed to the mother’s body temperature. The amniotic fluid increases in volume as the foetus grows, with the greatest amount at about 34 weeks GA (gestational age). At 34 weeks GA, the amount of amniotic fluid is about 800 ml. This amount reduces to about 600 ml at 40 weeks GA when the baby is born. Throughout the mother’s pregnancy amniotic fluid is continually being swallowed and ‘inhaled’ and replaced through being ‘exhaled’, as well as being urinated by the baby. Though the fluid would not be terribly tasteful to us, the developing baby does not seem to mind it at all. It is essential that the amniotic fluid be breathed into the lungs by the foetus in order for the lungs to develop normally.

Analysis of amniotic fluid, drawn out of the mother’s abdomen in an amniocentesis procedure, can reveal many aspects of the baby’s genetic health. This is because the fluid also contains foetal cells which can be examined for genetic defects. Amniotic fluid also protects the developing baby by cushioning it against blows to the mother’s abdomen, allows for easier foetal movement, promotes muscular or skeletal development and helps protect the foetus from heat loss. Amniotic fluid? We all knew it very well—it used to be all around us.²³, ²⁴

For roughly 6 to 7 months after birth, an infant can breathe and swallow at the same time. This ability was beneficial before the infant was born when it lived in the watery environment of the mother’s womb.²⁵, ²⁶

The navel divides a baby directly in half by length.