Speaker 1: Usually when you swallow a medication, there's this underlying expectation
Speaker 1: of magic. Oh, absolutely, you take a pill, wash it
Speaker 1: down with a glass of water, and well, twenty minutes later,
Speaker 1: your debilitating migraine is just gone or your blood pressure stabilizes.
Speaker 2: Yeah, it really does feel like you just cast a
Speaker 2: localized spell on your own biology.
Speaker 1: It does. It creates this illusion of effortlessness. We tend
Speaker 1: to picture like a tiny intelligent chemical wizard navigating through
Speaker 1: the dark corridors of our anatomy, knowing exactly where to
Speaker 1: go and what to fix.
Speaker 2: Right, But the reality is far more mechanistic and frankly,
Speaker 2: I think it's a lot more fascinating. Drugs do not
Speaker 2: operate by magic. They operate by hacking.
Speaker 1: Hacking into a very complex, pre existing biological blueprint, which
Speaker 1: is exactly what we're looking at today. We are doing
Speaker 1: a deep dive into the foundational research and notes surrounding
Speaker 1: human anatomy, specifically pulling from Gail Sloan Thompson's understanding anatomy
Speaker 1: and physiology to really figure out how our bodies act
Speaker 1: as this ALTI programmable machinery.
Speaker 2: And this is foundational. I mean, you cannot master pharmacology,
Speaker 2: which is the study of how drugs alter the body.
Speaker 2: Without first mastering the baseline physiology, you have to know
Speaker 2: how the body operates on its own exactly.
Speaker 1: So, whether you are a pharmacy student, a young professional
Speaker 1: in healthcare, or just you know, a self learner rigorously
Speaker 1: trying to understand your own biology, you have to know
Speaker 1: the normal traffic patterns, because otherwise you can understand what
Speaker 1: happens when a chemical agent forces a detour.
Speaker 2: So true, and to understand those traffic patterns, we actually
Speaker 2: have to bypass the major organs at first. We need
Speaker 2: to zoom all the way down to the chemical level,
Speaker 2: to the individual cell, right.
Speaker 1: Because everything a drug does ultimately boils down to atoms,
Speaker 1: elements and how they bond together. The source goes into ionic,
Speaker 1: covalent and hydrogen bonds. But the most crucial player here
Speaker 1: is just water.
Speaker 2: Water is incredible. It's held together by weak magnetic attractions
Speaker 2: hydrogen bonds, which gives it this unique polarity.
Speaker 1: That polarity makes water the ultimate biological solvent, doesn't it.
Speaker 2: It really does. Because the water molecule has a slightly
Speaker 2: positive end and a slightly negative end. It acts like
Speaker 2: a magnet. It literally pulls other molecules.
Speaker 1: Apart, breaking down large chemical compounds into individual ions that
Speaker 1: our cells can actually process.
Speaker 2: Exactly. Without that solvent capability, a swallowed pill would just
Speaker 2: sit in your stomach. It would be entirely inert.
Speaker 1: Wow. And beyond just dissolving things, water is well, it's
Speaker 1: the primary mechanical lubricant of the human machine.
Speaker 2: Yeah. It allows the heart to constantly beat against the
Speaker 2: surrounding tissue without friction. It keeps joints moving smoothly, and
Speaker 2: provides the fluid matrix for your blood. It really sets
Speaker 2: the physical stage for all biological chemistry.
Speaker 1: So setting that stage brings us to the cells themselves.
Speaker 1: We have trillions of them, and every single one functions
Speaker 1: as a microscopic fortified city, a.
Speaker 2: City with a very strict border wall, the selectively permeable
Speaker 2: plasma membrane, right, And.
Speaker 1: To keep the cell alive, utans and drug molecules have
Speaker 1: to find a way past that wall, and cellular waste
Speaker 1: needs to get.
Speaker 2: Out, which brings us to cellular transport. The simplest mechanism
Speaker 2: across that wall is diffusion.
Speaker 1: Passive movement, right, the.
Speaker 2: Passive movement of particles from an area of higher concentration
Speaker 2: to an area of lower concentration.
Speaker 1: I always like to visualize diffusion like a VIP line
Speaker 1: outside a nightclub.
Speaker 2: Oh, that's a great way to look at it.
Speaker 1: Yeah, once the doors open, the dense crowd in the
Speaker 1: line naturally spreads out right. They flow effortlessly into the
Speaker 1: empty space of the club. And the best part is
Speaker 1: it requires absolutely zero energy from the cell, none.
Speaker 2: At all, and that natural flow governs so much of
Speaker 2: our physiology. A really specific critical variation of this is osmosis.
Speaker 1: That's the diffusion of water itself, right.
Speaker 2: Exactly, water moving across that selectively permeable membrane. The water
Speaker 2: moves toward the side with the higher concentration of salutes,
Speaker 2: that dissolved particles, just trying to equalize the concentration on
Speaker 2: both sides.
Speaker 1: And this is where the concept of tonicity comes in, which,
Speaker 1: if you're in a clinical setting, is massively important. Tunicity
Speaker 1: basically dictates how a fluid affects the pressure and volume
Speaker 1: inside a cell.
Speaker 2: Right, So if an IV bag is completely isotonic, it
Speaker 2: matches the salute concentration inside your cells perfectly. Fluid flows
Speaker 2: in and out evenly. You maintain a stable equilibrium.
Speaker 1: But consider what happens if you introduce a hypertonic solution,
Speaker 1: like one with a much higher concentration of salutes than
Speaker 1: the cell's interior.
Speaker 2: The water inside the cell will aggressively rush out to
Speaker 2: dilute the surrounding fluid, and that causes the cell to
Speaker 2: rapidly shrivel up and dehydrate.
Speaker 1: And the reverse is just as dangerous. Right if you
Speaker 1: introduce a hypotonic solution, say pure salute free water, the
Speaker 1: fluid rushes into the more concentrated cell and.
Speaker 2: Causes it to swell up and potentially even burst, Which
Speaker 2: is why medical professionals can't just pump pure tap water
Speaker 2: into your veins. The tnicity has to be meticulously calculated.
Speaker 1: To prevent completely destroying your red blood exactly.
Speaker 2: Now, those passive processes govern a lot of movement, but
Speaker 2: cells frequently need to force substances against that natural gradient.
Speaker 2: They have to push things from low concentration back up
Speaker 2: to high concentration.
Speaker 1: Which is active transport.
Speaker 2: Yes, that requires the cell to spend its own energy
Speaker 2: currency known as ATP to physically force molecules across the membrane.
Speaker 1: The most vital example of this is the sodium potassium pump.
Speaker 1: Going back to my nightclub visualization, if passive diffusion is
Speaker 1: the effortless VIP line, the sodium potassium pump is the bouncer.
Speaker 2: I love that, a very tired bouncer, right.
Speaker 1: This mechanism actively burns atp energy to force fully drag
Speaker 1: three rowdy patrons the sodium ions out of the cell
Speaker 1: against the crowd while simultaneously ushering two preferred guess potassium
Speaker 1: ions inside.
Speaker 2: And the mathematics of that exact exchange are literally the
Speaker 2: key to human life. By constantly pumping three positive sodium
Speaker 2: ions out but only bringing two positive potassium ions in,
Speaker 2: the bouncer creates a deficit.
Speaker 1: Making the inside the cell slightly more negative than the outside.
Speaker 2: Exactly, the membrane is now polarized. It holds this unstable
Speaker 2: electrical charge, kind of like a drawn bowstring, just waiting
Speaker 2: to be released.
Speaker 1: And that stored electrical tension is the literal spark of
Speaker 1: the nervous system. Without that sodium potassium pump maintaining the polarity,
Speaker 1: our nerves couldn't communicate a single sensation, our muscles couldn't twitch.
Speaker 2: But when a neuron is finally stimulated, that drawn bowstring snaps,
Speaker 2: the cellular gates suddenly fly open.
Speaker 1: And because the bouncer pushed all that sodium outside, the
Speaker 1: moment the gates open, sodium violently rushes back into the cell.
Speaker 2: Yes, this sudden influx of positive ions flips the electrical
Speaker 2: charge entirely. That creates an action potential.
Speaker 1: You know, people often compare an action potential to a
Speaker 1: spark traveling down a fuse, but I think it's actually
Speaker 1: much closer to the wave in a crowded sports stadium.
Speaker 2: Oh that's a really accurate analogy.
Speaker 1: Yeah, because the individual peopole or the ions in this case,
Speaker 1: aren't running around the stadium. They just stand up and
Speaker 1: sit down in their specific local spot. The gates open,
Speaker 1: sodium rushes in, and that local flip and charge triggers
Speaker 1: the gates next door to open, and.
Speaker 2: The electrical signal just cascades down the nerve fiber. And
Speaker 2: immediately after the wave passes, repolarization kicks in. Potassium rushes
Speaker 2: out of the cell to reset that negative internal.
Speaker 1: Charge, so the neuron is ready to fire again. But
Speaker 1: the wave eventually reaches the end of the nerve fiber,
Speaker 1: which presents a structural problem. There's a physical gap the
Speaker 1: synaptic cleft between the nerve ending and the next cell.
Speaker 2: Right, the electrical stadium wave cannot jump across empty space.
Speaker 1: So the body has to convert the electrical signal into
Speaker 1: a chemical one exactly.
Speaker 2: The nerve ending releases chemical messengers called neurotransmitters. These molecules
Speaker 2: flood across the synaptic cleft and physically bind to receptors
Speaker 2: on the target.
Speaker 1: Cell, and depending on the neurotransmitter, it commands that target
Speaker 1: cell to fire its own electrical wave, or to contract
Speaker 1: if it's a muscle, or secrete horn if it's a gland.
Speaker 1: The scale of this communication network is just staggering.
Speaker 2: It really is. You have the somatic division handling voluntary
Speaker 2: commands like you know, moving your arm, but the autonomic
Speaker 2: nervous system runs entirely in the background, managing the body's
Speaker 2: subconscious machinery.
Speaker 1: Which is split into two opposing factions, the sympathetic and
Speaker 1: the parasympathetic.
Speaker 2: Right, the sympathetic division drives the fight or flight response.
Speaker 2: When your brain perceives a threat, sympathetic nerves flood the system.
Speaker 2: They command the heart rate to.
Speaker 1: Spike, They dilate the blood vessels routing to your skeletal
Speaker 1: muscles so you can sprint, and simultaneously they inhibit intestinal
Speaker 1: motility because digesting lunch is biologically irrelevant if you are
Speaker 1: actively trying to survive a predator exactly.
Speaker 2: And then the parasympathetic division is the counterbalance the rest
Speaker 2: and digest state. It actively lowers the heart rate and
Speaker 2: routes blood back to the gastrointestinal track to resume digestion.
Speaker 1: Now, this nervous system communication is lightning fast and highly targeted,
Speaker 1: but the d also relies on a secondary, much slower
Speaker 1: command center, the endocrine system.
Speaker 2: Right, instead of firing targeted electrical waves, the endocrine system
Speaker 2: broadcasts its messages by dumping hormones directly into the bloodstream.
Speaker 2: The goal here is long term homeostasis, maintaining a stable
Speaker 2: internal environment despite external changes.
Speaker 1: The pancreas is a great example.
Speaker 2: This isn't it a perfect example. After a large meal,
Speaker 2: your blood glucose levels inevitably spike. Beta cells in the
Speaker 2: pancreas detect this and release the hormone insulin into.
Speaker 1: The blood, and insulin acts as a widespread storage signal.
Speaker 1: It prompts the liver to convert floating glucose into stored glycogen,
Speaker 1: driving blood sugar levels back down.
Speaker 2: But when you skip a meal and your blood sugar
Speaker 2: starts to crash, the pancreas pivots alpha cells release a
Speaker 2: different hormone called glucagon.
Speaker 1: Which acts as a release signal, commanding the liver to
Speaker 1: break apart that stored glycogen and flood the bloodstream with glucose.
Speaker 1: So your brain keeps functioning. But wait, I have a
Speaker 1: question about this.
Speaker 2: Sure, what is it?
Speaker 1: If the blood is just this giant chemical soup carrying
Speaker 1: dozens of neurotransmitters, insulin, glucagon, and potentially pharmaceutical drugs, all
Speaker 1: at the exact same time, how does a cell know
Speaker 1: what to listen to? I mean, why doesn't my heart
Speaker 1: accidentally react to an insulin molecule? It just seems like
Speaker 1: total chaos in there.
Speaker 2: That's a great point. The mechanism preventing that total chaos
Speaker 2: is the absolute specificity of cellular receptors. It's the classic
Speaker 2: lock and key principle of biology. A cell doesn't just
Speaker 2: absorb whatever chemical bumps against its membrane. It bristles with
Speaker 2: these highly specific, complex protein structures on its surface. Insulin
Speaker 2: acts as a precise molecular key that only fits into
Speaker 2: an insulin receptor lock.
Speaker 1: So if a heart muscle cell lacks the specific receptor for,
Speaker 1: say a certain digestive hormone, it's completely blind to it.
Speaker 2: Exactly. The hormone just physically bounces off and floats away
Speaker 2: in the bloodstream without triggering any internal reaction whatsoever.
Speaker 1: That makes a lot of sense, And that's exactly the
Speaker 1: concept pharmaceutical engineers exploit, isn't it It is.
Speaker 2: The vast majority of drugs are simply synthetic keys, designed
Speaker 2: in a laboratory their shape to perfectly fit into specific
Speaker 2: human receptor locks. Right.
Speaker 1: So, some drugs are agonists, meaning they turn the lock
Speaker 1: and trigger the cell to perform an action, and other
Speaker 1: drugs are antagonists, where they jam the lock, blocking the
Speaker 1: body's natural hormones from attaching precisely.
Speaker 2: But none of these natural hormones or synthetic drugs can
Speaker 2: reach their specific locks without a delivery network, which brings
Speaker 2: us to the transport highway.
Speaker 1: The cardiovascular system and the blood itself.
Speaker 2: Yeah, and interestingly, blood is biologically categorized as a connective tissue.
Speaker 2: It consists of a fluid plasma matrix carrying millions of
Speaker 2: formed elements, primarily red.
Speaker 1: Blood cells, and those red blood cells are packed with
Speaker 1: a complex protein called hemoglobin, which contains a central hay
Speaker 1: molecule built around an iron.
Speaker 2: Atom, and that specific iron atom is what binds to
Speaker 2: oxygen in the lungs, allowing the blood to ferry oxygen
Speaker 2: to every distant tissue.
Speaker 1: But this fleet of red blood cells has a strict
Speaker 1: expiration date.
Speaker 2: Oh yeah. As they circulate, they sustain a lot of
Speaker 2: physical damage. So the liver and the spleen constantly filter
Speaker 2: out and break down these old, battered cells. They salvage
Speaker 2: the iron to be recycled, while the bone marrow continuously
Speaker 2: manufactures replacements.
Speaker 1: And to propel this massive, thick cargo network, the body
Speaker 1: requires a relentless engine. The heart. It's built of several
Speaker 1: distinct layers. You've got the endocardium lining the smooth interior,
Speaker 1: the paar cardial sac protecting the exterior. But the driving
Speaker 1: force is the middle layer, the myocardium.
Speaker 2: The myocardium is that dense muscular wall of the heart.
Speaker 2: When it contracts, it generates hydrostatic pressure. That's the raw
Speaker 2: physical force pushing the blood through the vessels.
Speaker 1: And this blood pressure is heavily regulated by three interconnected variables.
Speaker 1: First is cardiac output, which measures the total volume of
Speaker 1: blood the heart injects every minute right.
Speaker 2: Second is the overall blood volume, literally how much fluid
Speaker 2: is trapped inside the closed loop of your veins and arteries.
Speaker 2: Fluid in the same space equals higher pressure.
Speaker 1: And third is resistance. The blood vessels are lined with
Speaker 1: smooth muscle. When they constrict, narrowing the pipes, resistant spikes
Speaker 1: and pressure goes up, which is.
Speaker 2: Crucial because the entire purpose of generating that immense arterial
Speaker 2: pressure is to ensure that blood actually reaches the furthest
Speaker 2: most microscopic vessels in the body, the capillaries.
Speaker 1: Because the capillary beds are where the actual physiological trade occurs.
Speaker 2: Yes, and this capillary exchange is this elegant tug of
Speaker 2: war between two opposing physical forces. On one side, you
Speaker 2: have that hydrostatic pressure we just mentioned, the engine of
Speaker 2: the heart physically forcing blood against the incredibly thin walls
Speaker 2: of the capillary, squeezing fluid, oxygen and nutrients out into
Speaker 2: the surrounding tissue space.
Speaker 1: But if hydrostatic pressure was the only force at play,
Speaker 1: your blood vessels would continuously leak fluid until your tissues
Speaker 1: swelled up with massive life threatening edema.
Speaker 2: Exactly, the body requires a retrieval mechanism to pull fluid
Speaker 2: back into the vascular system. That opposing force is osmotic pressure.
Speaker 1: Think of it like a soaker hose in a garden.
Speaker 1: The water pressure inside the hose hydrostatic pressure forces water
Speaker 1: out through the tiny pores to water the soil. But
Speaker 1: now imagine the water inside that hose was packed with large,
Speaker 1: highly concentrated, spongy proteins that couldn't fit through the pores.
Speaker 2: That is exactly what happens. Those proteins, primarily album and
Speaker 2: manufactured by the liver, remain trapped inside the blood vessel.
Speaker 2: Because they're so highly concentrated. They create a powerful osmodic pull,
Speaker 2: acting like a sponge, yes, drawing the fluid, which is
Speaker 2: now loaded with cellular waste and carbon dioxide, back out
Speaker 2: of the tissue spaces and into the capillary So hydrostatic
Speaker 2: pressure pushes out, osmotic pressure pulls back in.
Speaker 1: It's a perfect balance. But once that fluid is pulled
Speaker 1: back into the veins, the blood is essentially carrying the
Speaker 1: body's trash. It's picked up cellular waste, metabolic byproducts, and
Speaker 1: the remnants of any drugs you ingested in.
Speaker 2: This tox a cargo must be filtered out before it
Speaker 2: circulates back to the heart. We are heading into the
Speaker 2: renal system.
Speaker 1: The kidneys the ultimate biological filtration plants. They form urine
Speaker 1: and cleanse the blood through three highly regulated steps.
Speaker 2: Right, it begins with glanarular filtration. The blood is forced
Speaker 2: under high pressure into a microscopic knot of capillaries called
Speaker 2: the glomerulus. The pressure physically squeezes water urea in small
Speaker 2: salutes out of the blood and into the renal tubule.
Speaker 1: But the problem with this aggressive physical squeezing is that
Speaker 1: it filters out a massive amount of valuable material too.
Speaker 1: It pushes out water, glucose, and essential electrolytes that the
Speaker 1: body desperately needs to keep, which is.
Speaker 2: Why the second step, tubular reabsorption, is so critical. As
Speaker 2: this raw filtered fluid travels down the long winding renal tubule,
Speaker 2: the cells lining the tubule meticulately actively transport the glucose, sodium,
Speaker 2: and water back into the bloodstream. It's a highly selective
Speaker 2: reclamation process.
Speaker 1: Then the final step is tubular secretion. The kidney acts
Speaker 1: proactively here. It doesn't just wait for things to passively
Speaker 1: filter out. It actively burns energy to grab large toxic molecules,
Speaker 1: excess hydrogen ions and drug metabolites remaining in the blood
Speaker 1: and pumps them directly into the tubule to be permanently excreted.
Speaker 2: Looking at this entire mechanism, the kidney is acting as
Speaker 2: far more than just a was shoot.
Speaker 1: Oh. Absolutely, it's more accurate to think of it as
Speaker 1: the body's ultimate master accountant, right, just continuously balancing the
Speaker 1: complex ledgers of water volume, sodium concentration, and blood pressure.
Speaker 2: That is a perfect way to phrase it. And the
Speaker 2: absolute pinnacle of this accounting work is a feedback loop
Speaker 2: known as the RaaS the renin angiotensin aldosterone.
Speaker 1: System, which is a primary target for countless pharmacological interventions.
Speaker 1: It starts when the kidneys detect a dangerous drop in
Speaker 1: overall blood pressure.
Speaker 2: Right the moment pressure drops, the kidneys secrete an enzyme
Speaker 2: called rennin into the blood. Renin initiates a chemical cascade
Speaker 2: that ultimately converts a circulating protein into an active hormone
Speaker 2: called angiotens in the second and.
Speaker 1: Angiotens in the second is one of the most potent
Speaker 1: vasoconstrictors in the human body. It immediately binds to receptors
Speaker 1: on the blood vessels, causing them to clamp down shirky,
Speaker 1: increasing resistance and driving blood pressure up.
Speaker 2: But its secondary function is just as vital. It travels
Speaker 2: to the adrenal glands and triggers the release of the hormoneldosterone.
Speaker 1: Which communicates directly with the renal tubules. It commands the
Speaker 1: kidneys to stop excreting sodium and instead aggressively retain it,
Speaker 1: pulling it back into the blood.
Speaker 2: And returning to our rules of osmosis, we know that
Speaker 2: water relentlessly follows salutes. As the kidneys pull sodium back
Speaker 2: into the blood, massive amounts of water follow it. Blood
Speaker 2: volume expands and blood pressure is restored to normal.
Speaker 1: Incredible, and in addition to managing blood volume, this system
Speaker 1: is heavily involved in managing the botter's acid base balance,
Speaker 1: keeping blood pH strictly neutral.
Speaker 2: Yes, though the kidneys manage pH in close partnership with
Speaker 2: the respiratory.
Speaker 1: System, because cellular metabolism and constantly produces carbon dioxide as
Speaker 1: a waste product. If carbon dioxide builds up in the blood,
Speaker 1: it converts into carbonic acid causing blood pH to drop
Speaker 1: into a dangerous acidic state.
Speaker 2: Exactly, and central chemo receptors located in the brainstem monitor
Speaker 2: the pH of the blood with absolute precision. The moment
Speaker 2: they detect an acidic shift due to rising carbon dioxide,
Speaker 2: they override your normal breathing patterns.
Speaker 1: They signal the lungs to increase the rate and depth
Speaker 1: of respiration.
Speaker 2: Right forcing you to hyperventilate slightly, just enough to blow
Speaker 2: off the excess carbon dioxide gas, shifting the blood pH
Speaker 2: back to a neutral baseline.
Speaker 1: Every single system we've explored is inextricably linked, from the
Speaker 1: polarity of the sodium potassium pump on a single microscopic cell,
Speaker 1: to the stadium wave of a firing neuron, down the
Speaker 1: pressurized cardiovascular highway, and through the rigorous accounting ledgers of
Speaker 1: the kidney.
Speaker 2: To solidify how these systems integrate, you should try this
Speaker 2: mental exercise for anyone listening. Trace the physical journey of
Speaker 2: a standard oral medicaid.
Speaker 1: Okay, let's walk through it.
Speaker 2: You swallow the pill. It dissolves in the watery, polarized
Speaker 2: environment of your stomach. It diffuses across the plasma membranes
Speaker 2: of your gastrointestinal tract to enter the vascular system.
Speaker 1: Then it's pumped by the hydrostatic pressure of the myocardium
Speaker 1: through the liver, where enzymes attempt to metabolize.
Speaker 2: It yes, and it rides the capillary exchange to reach
Speaker 2: a specific target tissue where it acts as a synthetic
Speaker 2: key binding to a highly specific receptor LOG to alter
Speaker 2: a cellular function.
Speaker 1: And finally, the remaining drug metabolites travel to the kidneys
Speaker 1: where they are actively secreted into the renal tubule and eliminated.
Speaker 2: It really is a remarkable journey of biological hacking.
Speaker 1: It is. But before we conclude this deep dive into
Speaker 1: our physiological blueprint, consider a concept pulled from the final
Speaker 1: chapter of our source material regarding the human microbiome.
Speaker 2: Oh. This forces a massive paradigm shift in how we
Speaker 2: view anatomy. We are not just a sterile collection of
Speaker 2: human cells. The bacteria living on our skin and deep
Speaker 2: inside our gastro intestinal tract outnumber our own human cells
Speaker 2: by a ratio of ten to one.
Speaker 1: Ten to one. Movie roobes make up the vast bulk
Speaker 1: of our internal environment, which leaves you with a deeply
Speaker 1: provocative question when you ingest a pharmaceutical drug, how much
Speaker 1: of that pharmacology is actually treating your human systems.
Speaker 2: And how much of it is interacting with or being
Speaker 2: metabolized by the trillions of bacteria that intercept the drug
Speaker 2: before it ever reaches your own cells.
Speaker 1: It proves that our physiological blueprint is even more complex
Speaker 1: than we realize, requiring us to constantly reevaluate how interventions
Speaker 1: actually work.
Speaker 2: The machinery is infinitely complex.
Speaker 1: So the next time you take a pill and read
Speaker 1: for the relief to wash over, you remember you aren't
Speaker 1: casting a spell. You are deploying a highly specific chemical
Speaker 1: key into a bustling, trillion celled, perfectly balanced biological engine.