Image by Cathy Keifer
We’ve all marveled at how a fat creeping caterpillar (Version 1 – V.1.) comes out of its chrysalis as an elegant and beautiful butterfly (Version 2 – V.2.). It’s as if there are two separate sets of DNA. If you looked at the two versions side by side you would never guess one came from the other. That’s a major remodel! Frogs are another example of a transformation in nature. Life begins as a tadpole, using gills to extract oxygen from the water. These gills dissolve and lungs begin appearing in preparation for the soon to appear frog version. For our tadpole is destined to be an air-breathing frog, extracting oxygen from air and not water.
Guess what? At your birth you went through a transformation too, leaving the fluid-filled warmth of your mother’s womb to emerge out into the cold air-filled room to take your first breath. Let’s go back to your beginning and follow the mysterious and seemingly magical process which led to that first breath.
Dr Yorgos Nikas/Science Photo Library
One cell, that was the beginning of you, smaller than the tip of a needle. As that one cell divided until you were a clump of identical cells, each of those cells needed oxygen. Where did that oxygen come from since you didn’t have lungs yet? It came from your mother. When she became pregnant with you, she was now eating for two, breathing for two, and removing the trash for two. Though most mothers would say they experienced shortness of breath during pregnancy, their air intake actually increased! Their blood, which picks up and carries the oxygen, also increased its volume by 40%. (1) These changes, and many more, were caused by chemical messengers named hormones which were released into her bloodstream when you began growing. All of these changes were designed by God to help your mother’s body take care of you as you grew.
So, how does her oxygen get to that clump of cells which was you? Some people think that both mom and baby must share the same blood, so that her blood travels to your cells and delivers oxygen to them. You should be glad that’s not how it happens. Babies and their mothers do not necessarily have the same blood type, and if two different blood types mix it begins clotting, leading to serious problems and even death. The solution to the problem came through a special organ that only appears during pregnancy. It was neither part of your mom nor part of you, but you were responsible for forming it. What is it? It is called the placenta. (2) But, how do the nutrients and oxygen actually cross over to you so that her blood and yours don’t mix?
Your delivery system worked like this: Your mom’s blood carried oxygen from her lungs and nutrients from her stomach throughout her body, making deliveries to her cells. Some of her blood entered the placenta where your blood was waiting on the other side of a thin membrane. Oxygen and nutrients that were left in her blood could then pass through the membrane to enter your blood. So, you are really getting leftovers, what your mom’s body didn’t use. This shouldn’t alarm you. Your factory settings included a special version of hemoglobin (HbF) (the molecule that picks up and carries oxygen) that had a stronger attraction to oxygen than the hemoglobin your body makes now (HbA). This meant you were able to extract the oxygen from your mom’s blood even when her levels were low.(3) It’s pretty amazing how all these critical factors ended up working perfectly to bring you the nourishment and oxygen you needed to grow.
And grow you did! By Day 21 of your life, while you were still smaller than this circle, “o”, you had formed two tubes which would grow into your heart. (4) Your umbilical cord brought blood rich with oxygen from the placenta to your heart where it was then pumped to all the cells in your growing body. This system worked perfectly for you during your stay in “Hotel Mom”, but when you were born a huge transformation (change) was needed.
How Your Heart Pumps Blood Now
Put your hand over the left side of your chest. Can you feel your heartbeat? It is pumping your blood. The top right chamber called the right atrium receives blood from the veins in your body (1,2). It then passes through a valve to your lower right chamber (ventricle) (3) which then pumps this blood to your lungs to pick up oxygen (4). This blood now carrying oxygen is brought back to the left atrium (5, 6) which dumps it down so that the left bottom chamber (ventricle) (7) can with a mighty contraction (squeeze) pump this blood up through the aorta to your whole body (8).
How Your Heart Pumped Blood While Inside Your Mom
Did you know that when you were growing inside your mom you had a hole in your heart, and that you needed that hole to be there? As blood entered your right atrium it poured through that hole into your left atrium before it could be pumped to your lungs. Pumping blood to your lungs would have been harmful to you. Your growing lungs were filled with fluid, not air. This fluid caused a high pressure that, if your body did what it does now (pumps blood to your lungs), would have resulted in not enough blood reaching the rest of your body, especially your growing brain. This hole has a name - foramen ovale.
Now, not all the blood makes it through the foramen ovale and some ends up in the right ventricle. When the right ventricle contracts (squeezes) it pumps this remaining blood out through the pulmonary arteries towards your lungs. Uh-oh, that’s not what you wanted to happen! Your second protection to keep blood from being pumped to your lungs is a trap door called a shunt. This shunt, called the ductus arteriosus (see above) redirected this blood away from the pulmonary artery into the aorta to be carried towards the rest of your body, just like a real or toy train track has diverters to redirect the train onto another track.
A tadpole’s lungs begin developing around the same time its legs start growing. Tadpoles at that stage will swim up to the surface and take a gulp of air. Your lungs began forming around Day 35 but were not completely formed until right before you were born. In fact, your lungs were the only major organ in your body that was non-functional (not working) while in the womb. As your bronchioles developed and branched into what looked like an upside-down tree, tiny air sacs called alveoli formed at the end of the tiny branches of the tree. They resembled miniature grapes in a cluster. The air you are now breathing travels down until it fills one of your tiny alveoli, and from there it is picked up by your blood cells and carried to all the cells in your body. As you can see, your alveoli play a very important role in keeping you alive. But, in “Hotel Mom” as your lungs were forming in preparation for V.2. you had a major problem to solve with your alveoli, and it had to do with something called surface tension.
Credit: Photo from Shutterstock
You see, water molecules are strongly attracted to other water molecules, just like one tiny magnet is to another. This is because a water molecule is “polar”, meaning it has a positive end and a negative end, just like magnets have north and south ends (poles). This “polarity” makes the positive end of one water molecule attracted to the negative end of another water molecule. This attractive force is called cohesion and it causes the water molecules on the surface to form a “net”, just like they were all “holding hands” with each other. This “net” is called surface tension. That’s why a water skeeter can zoom around on the surface of water without sinking. To explore the surface tension of water on your own you can perform the activities at the end of this article
What does this have to do with your first breath? Your developing alveoli were destined to be coated with a thin film of water which would allow the oxygen molecules to dissolve and pass through into your blood. Since the tiny alveoli are only the size of a grain of salt, the film of water on one side would be close enough to pull the other side to it, causing the sides of your alveoli to stick together. Oh, no! This is called alveolar collapse and would have been a medical emergency. These tiny sacs must remain open in order to be filled with the air you breath in. Once they are collapsed, trying to inflate them with air would be like trying to blow up a balloon that was flat on a table with a heavy weight on top of it. Good luck! Even if with tremendous effort you were able to inflate them with air, they would have collapsed again when you breathed out.
Surfactant forces the water molecules apart
The solution to your problem was surfactant, which special cells in your lungs somehow “knew” to begin secreting around week 25 of your life. (5) A surfactant is something which reduces the surface tension of water. This wonderful chemical which your little body manufactured (boy, how did you learn advanced chemistry at such a young age?) was a special mixture of fats and proteins. When mixed with water the surfactant molecules push their way in between all the water molecules which had been “holding hands”, forcing them to separate. Once separated they can no longer make the sides of the alveoli stick together. Now that we’ve discussed your foramen ovales, your ductus arterioles, and surfactant, we’re finally ready to go back and witness your first breath.
There you were, just out of your mother’s womb, and covered with a cheesy-white substance called vernix which protected your skin from becoming water-logged during your 9 months of being submerged in amniotic fluid. Of course, you were cold out in the air with no clothes on, but that was important for your first breath. This drop in temperature was relayed to your brain stem where your breathing center was located. These signals were also combined with low oxygen warning signals sent to your breathing center when your umbilical cord was cut and you lost your mom’s oxygen supply. Your time had come to breathe on your own. Your breathing center sent an urgent message to your breathing muscles to take your first breath. Uh-oh, wait a minute! Do you remember how for months your blood had been diverted away from your lungs? You had to find a way to close both the foramen ovale and the ductus arteriosis.! Let’s see how doctors solved a similar problem to perform the first successful open-heart surgery.
Dr. John Gibbon with Heart-Lungs Machine that he designed and used for successful open-heart surgery.
The problem doctors encountered when trying to perform surgery to repair a heart was that it was continually beating (imagine trying to thread a needle that was taped to a bouncing ball). The solution, first successfully used in 1953 to repair a right atrium defect in an 18-year-old girl, was the heart-lung machine. (6) Before operating on her heart the surgeon used a shunt inserted into the vena cava to divert blood through a tube into the heart-lung machine. The machine, acting like lungs and heart, then oxygenated the blood and pumped it back through another shunt into the patient’s aorta so the precious oxygen could be delivered to all her waiting cells. A chemical was used to temporarily stop the heart from contracting so they could repair the heart while it was still. When the repair was complete another chemical caused her heart to begin beating again. The shunts that diverted blood to and from the heart-lung machine were removed and insertion points stitched up, bringing the patient’s breathing and circulation back to normal. Now that we understand this miracle of medicine, let’s get back to your first breath.
Just like the patient underwent a change of how she received oxygen during her surgery, so did you at your birth. And just like the shunts in the surgery, your shunts also had to be removed, but in your case, no surgeon was necessary. Instead, your problem was solved through pressure. Your lungs that had been filled with fluid, were now filled with air. This lower pressure forced the first shunt, the foramen ovale, to close. The second shunt, the ductus arterioles, was pinched shut by muscles when a special hormone produced by the placenta stopped being made. Now your blood was able to be pumped to your lungs through the pulmonary arteries and veins which had been prepared for this exact moment.
Are you catching the planning and design of this amazing transformation from V.1 to V.2? Do you see how, just like the butterfly, your DNA included instructions to build the “plumbing” for both V.1 and V.2 of you? Your DNA master plan also included instruction for when and how to make the transformation. To help you appreciate the timing of all this, just think what would have happened to that 18 year old girl in surgery if the doctor had turned off the heart-lung machine, started the heart beating, but had forgotten to remove the shunts. Her blood would still be redirected to a non-functioning machine, and there would be no blood going to her heart to be pumped to her waiting cells. Now let’s get back to your first breath.
Image by Cradlecreations.com
I hope you realize that at that moment your parents and the doctors and nurses were all holding their breath as they waited for you to take your first one. And breathe you finally did. It may have taken even up to 30 seconds for you to begin regular breathing because of all those changes that were taking place in rapid succession. Your first tentative breath in (inhalation) caused your tiny alveoli to inflate with air for the first time, thanks to the help of the surfactant which your lung cells had been preparing for this moment. Yay! As you exhaled you instinctively used your glottis ( a flap which covers you windpipe so while swallowing your food doesn’t enter into your lungs) to slow down air leaving your lungs to make sure your alveoli didn’t collapse as the air left. Low oxygen levels might have turned your feet, hands and lips blue for a while until you were able to increase your oxygen supply through regular breathing. Your parents waited anxiously while the neonatal team tested your heart rate, breathing pattern, reflexes and overall health. I’m sure you impressed everyone there with how loud you could cry, putting any fears of poor health to rest! Everyone in the room took a deep breath and let it out, thankful for the miracle they had just witnessed.
Listen to what King David of Israel wrote long before there was any understanding about shunts, lungs, circulation and how the heart worked:
“For you formed my inward parts;
you knitted me together in my mother's womb.
14 I praise you, for I am fearfully and wonderfully made.[a]
Wonderful are your works;
my soul knows it very well.
15 My frame was not hidden from you,
when I was being made in secret,
intricately woven in the depths of the earth.
16 Your eyes saw my unformed substance;
in your book were written, every one of them,
the days that were formed for me,
when as yet there was none of them.”
Psalm 139: 13-16
Somehow David knew that his 9 months in the womb were a wonderful work of God. You know much more than David did about all the chemicals and processes necessary to your survival and how each one arrived on the scene at the perfect time. There must be a “Grand Master Planner” behind this grand master plan. While spending 9 months in “Hotel Mom” you can be sure she delighted in how you were growing, but both her body and yours were just operating according to this grand master plan whose one purpose was to bring you into this world. In fact, long before your first day in the womb, “when as yet there was none of them” God had already written down His plan for your life according to His wonderful plan for you.
Formed by God. That’s you. Knit together by God. That’s you. God saw you before anyone else, even when you were a clump of cells (unformed). Can you say with David, “I praise You, for I am fearfully and wonderfully made. Wonderful are your works; my soul knows it very well”?
End Notes:
1. Pregnancy involves an increase of a special chemical called progesterone. When this chemical reached her rib muscles they produced more relaxin, another chemical which relaxes the ligaments and tissue which hold bones together. Her rib cage or chest area grew bigger. Why? In several months you were going to get so big that you would push her diaphragm muscle up towards her ribs, making her lung volume decrease. However, now that her rib cage is larger her lung volume would remain the same (though it probably did not feel like it to her!)
2. https://www.nichd.nih.gov/research/supported/HPP/research_funding/human-placenta
3. https://www.ncbi.nlm.nih.gov/books/NBK500011/
5. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2880575/
6. https://www.annalsthoracicsurgery.org/article/S0003-4975(10)62507-6/pdf
Activity 1: Surface Tension of Water
Materials: wax paper; eye dropper; liquid soap; water; paperclip; cup; rubbing alcohol
1. Place 2 drops of water on top of each other on the wax paper. Observe the shape of the drop. Pick up the wax paper and see if you can role the drop around the wax paper. Are the water molecules more strongly attracted to each other or to the wax paper? How can you tell?
2. Add several drops of rubbing alcohol on the wax paper. Compare the size of a drop of water with a drop of rubbing alcohol on wax paper. Why are they different? Which molecules have a stronger attraction to each other?
3. Add several drops of liquid soap to some water in a cup. Place several drops of this water/soap liquid on the wax paper next to the pure water drop. Contrast their shapes. Try to roll the water/soap drop.
4. In a clean cup gently lower a paperclip onto the surface of water in the cup. (bend another paperclip to make a cradle to lower it). What is keeping the paperclip afloat even though it is more dense than water?
5. Carefully place one drop of soap in the cup while the paper clip is floating. What happens and why?