The Placenta: The Organ That Does it All

This organ appears out of nowhere,
runs four physiological systems at once,
directs maternal biology with biochemical mastery,
and orchestrates its own demise when its work is done

 

The Placenta: The Organ That Does it All

by John D. Wise, PhD

In my last article, “Evolutionary Biology Turns the Genome Upside Down,” we examined the intellectual acrobatics required to claim that one major part of the placenta (the STB) was a windfall from an ancient viral infection. When we step back from the details of that controversy, however, a much larger reality emerges. Come wonder with me at what God hath wrought!

The Placenta Is More Powerful—and More Mysterious—Than You Think (The MIT Press Reader, 5 October 2026). Adapted from neuroscientist Susana Carmona’s book A Mother’s Brain, this article offers an astonishing look at what the placenta does. Rather than getting bogged down in materialist origin myths, as we did last time, Carmona admires the multi-dimensional engineering that operates inside every mother’s womb.

Her opening description comically captures both the humble appearance and the etymological history of the term:

“People say it looks like broccoli, a tree, a bowl, a pizza, a crescent moon, a Frisbee, a pancake. Etymologically, ‘pancake’ is closest: Placenta means cake in Latin and comes from the Greek word plakoenta, which means flat cake.”

Behind that humble exterior is bio-engineering so intricate and precise that modern science is just beginning to grasp its sophistication.

An Embassy on Foreign Soil

One of the most persistent misconceptions about pregnancy is that the placenta is a maternal organ grown by the mother to shelter her child. Carmona clarifies the reality:

“Nearly all of its cells contain the baby’s DNA, though a handful contain the mother’s… Both the baby and the placenta develop from the cell formed when the egg and sperm fuse. The placenta’s origin, then, is fetal.”

From its very first cellular division, the embryo begins to build its own dynamic life-support system. The placenta is essentially a fetal embassy established inside maternal territory. Its arrival is marked by a controlled, purposeful invasion.

To nourish the growing child, the outer embryonic cells gently invade the mother’s uterine lining and physically remodel her spiral arteries, converting narrow, muscular blood vessels into wide, low-resistance channels.

In any other medical context, an aggressive tissue invasion that rewires arteries and alters local blood supply would be diagnosed as an aggressive tumor. Yet here, it proceeds with exquisite precision, halting at the exact cellular boundary required to preserve maternal health.

More Than a Bouncer: The Multi-Organ Stand-In

Once established, what does the placenta do? Popular culture often treats it as a passive sieve or a crude filter. Carmona corrects this misperception:

“Its best-known role is mediating between maternal and fetal bloodstreams. It is no mere bouncer deciding what can or cannot pass; it is a sophisticated entity charged with numerous tasks key to the pregnancy’s success.”

For an unborn baby bathing in amniotic fluid, none of the primary organ systems can function in their adult roles: the lungs are filled with fluid, the digestive tract receives no solid food, the kidneys produce urine that cycles back into the fluid, and the liver cannot yet process adult metabolic loads. How does the developing baby survive?

The placenta steps in and performs all of these jobs simultaneously:

“It takes on the roles of the lungs, gut, liver, and kidneys, since the fetus cannot yet use its own.”

• Lungs: the placenta extracts oxygen from maternal red blood cells and deposits fetal carbon dioxide into maternal circulation, executing high-speed gas exchange across delicate membrane layers without ever letting maternal and fetal blood directly mix.

• Gut and Liver: it actively harvests glucose, essential amino acids, and fatty acids from the mother’s blood, synthesizes metabolic intermediates, and pumps nutrients directly into the umbilical cord.

• Kidneys: it continuously filters nitrogenous waste products like urea and creatinine out of the fetal bloodstream, exporting them into the maternal system for disposal.

An AI Analogy: In human engineering, a machine capable of simultaneously acting as an oxygenator, a dialysis machine, a metabolic refinery, and a nutrient-delivery pump would fill a hospital room. The placenta accomplishes all four within a temporary, self-assembling disk that weighs barely a pound.

A Chemical Mastermind

The placenta does not simply serve the child; it actively manages the mother. Rather than resting passively inside the womb, it operates as an endocrine powerhouse:

“Placental hormones also fine-tune the cardiovascular, metabolic, and immune systems of the mother to ensure fetal survival.”

The placenta synthesizes massive amounts of progesterone and estrogen to maintain the pregnancy, alongside human placental lactogen (hPL), which systematically adjusts maternal insulin sensitivity.

By slightly raising the mother’s blood glucose levels, the placenta ensures that a steady supply of energy is directed toward the developing baby’s rapidly growing brain.

At the same time, it maintains an immunological truce. The placenta acts as a dynamic shield: it selectively transports maternal antibodies across the barrier to gift the baby with passive immunity for its first months of life outside the womb, while strictly suppressing maternal immune cells from attacking the child’s genetically distinct paternal proteins.

Talk about a finely choreographed dance!

The Temporary Wonder

Perhaps the most breathtaking feature of the placenta is its built-in expiration. Unlike the heart, brain, or liver, which are constructed to last a lifetime, the placenta is built for a single, nine-month mission. It coordinates its own rapid growth, works at maximum metabolic output, orchestrates the hormonal triggers that initiate labor, and then quietly detaches and exits the stage as the baby takes its first breaths.

When we strip away the evolutionary rhetoric that portrays life as an accidental series of random mutations and “domesticated parasites,” one of the realities left standing before us is an organ that appears out of nowhere, runs four physiological systems at once, directs maternal biology with biochemical mastery, and orchestrates its own demise when its work is done.

It is an easy, open-and-shut case of purposeful biological design.

To God be the glory … Great things He has done!

PREVIOUS CEH ARTICLES ON THIS TOPIC

• More Wonders Going on Inside you
• Your First Breath was Irreducibly Complex
• Darwin Follies and Fallacies, part 1
• Walk this Way: Body Designs Head to Toe
• Evolutionary Biology Turns the Genome Upside Down

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John Wise received his PhD in philosophy from the University of CA, Irvine in 2004. His dissertation was titled Sartre’s Phenomenological Ontology and the German Idealist Tradition. His area of specialization is 19th to early 20th century continental philosophy.

He tells the story of his 25-year odyssey from atheism to Christianity in the book, Through the Looking Glass: The Imploding of an Atheist Professor’s Worldview (available on Amazon). Since his return to Christ, his research interests include developing a Christian (YEC) philosophy of science and the integration of all human knowledge with God’s word.

He has taught philosophy for the University of CA, Irvine, East Stroudsburg University of PA, Grand Canyon University, American Intercontinental University, and Ashford University. He currently teaches online for the University of Arizona, Global Campus, and is a member of the Heterodox Academy. He and his wife Jenny are known online as The Christian Atheist with a podcast of that name, in addition to a YouTube channel: John and Jenny Wise.