pplpod

Tonic water glows blue under a black light because of quinine, a molecule this episode follows from the Andes to the bar cart. The Quechua people of Peru, Bolivia and Ecuador ground cinchona bark into sweetened water to stop shivering from cold. In the 1630s, Jesuit apothecary Agostino Salumbrino in Lima sent the bark to Rome, where malaria from the surrounding marshes was killing popes and cardin...

Touching your nose with your eyes closed relies on proprioception, the sense of body position, movement and force that neurophysiologist Charles Scott Sherrington named in 1906. This episode explains the hardware: muscle spindles that track muscle length and stretch speed, Golgi tendon organs that measure tension, and joint receptors that fire near a joint's limit. Insects and crabs use chordotona...

The vagus nerve, the tenth cranial nerve, takes its name from the Latin for wandering. This episode traces its route from the medulla oblongata through the jugular foramen, down the neck in the carotid sheath, through the chest and diaphragm, and out over the stomach, liver and colon. The right vagus holds up to 105,000 fibers and the left upwards of 87,000, and 80 to 90 percent of them are sensor...

Oxytocin is sold in pop science as the cuddle hormone, but this episode argues it works more like a biological volume knob for tribalism. Its name comes from Greek words for swift birth. In 1906 British pharmacologist Henry Hallett Dale found that a pituitary extract made the uterus contract, and in 1953 American biochemist Vincent du Vigneaud sequenced and synthesized the nine amino acid hormone,...

In late November 1803 the ship Maria Pita left A Coruña, Spain, carrying 22 orphan boys aged three to ten as living containers for Edward Jenner's cowpox vaccine. This episode tells the story of the Royal Philanthropic Vaccine Expedition led by military physician Francisco Javier de Balmis under a mandate from King Charles IV, whose own daughter had suffered smallpox. With no refrigeration, the va...

The weight you feel right now is not gravity but the floor pushing up against you. This episode starts there and builds a working explanation of g-force as a measure of acceleration, felt only when one surface presses against another. It walks through why upward acceleration feels identical to a heavier planet, why an unconditioned person sitting upright loses consciousness around four to five Gs,...

In the early 1990s, neurophysiologists at the University of Parma were recording single neurons in area F5 of macaque monkeys when a motor neuron fired as a monkey simply watched a researcher grab food. Nature rejected the finding for lack of general interest, yet mirror neurons became one of the most debated ideas in neuroscience. This episode explains that they are ordinary neurons classified on...

Michel Lotito, the French entertainer known as Monsieur Mangetout, could swallow a steel bicycle chain without distress, yet a banana gave him severe heartburn. This episode follows his life from his birth in 1950 in Villard-Bonnot, France, to the teenage years when he began eating strange objects, a habit doctors diagnosed as pica. Gastroenterologists found an unusually thick lining in his stomac...

For centuries, anxiety, fainting, insomnia, fluid retention, and even a tendency to cause trouble could all be diagnosed as hysteria, a word taken from the Greek for uterus. This episode traces the diagnosis from Egypt's Kahun Papyri around 1900 BC, which linked many complaints to the uterus, to the Hippocratic texts and Plato's Timaeus, which described a wandering womb seeking moisture. Aretaeus...

The winged staff wrapped by two snakes on ambulances, uniforms, and drug ads is the caduceus, and this episode explains why it historically has nothing to do with medicine. Its roots go back to Mesopotamia between 4000 and 3000 BC, where the underworld god Ningishzida bore a staff with two intertwined snakes, carved on the libation vase of the Sumerian ruler Gudea around 2100 BC. The symbol also a...

The name malaria comes from the medieval Italian for bad air, and for centuries people blamed the smell of swamps such as Rome's Pontine marshes for the disease called Roman fever. This episode traces malaria across more than 50,000 years, with a spike about 10,000 years ago as farming created mosquito habitat, and its arrival in the Americas with European settlers and the transatlantic slave trad...

The Mobile Army Surgical Hospital is best known from the television sitcom, but the real units were large, fast moving medical operations. This episode starts with the problem they solved: in World War II, wounded soldiers were stabilized and then driven for hours to hospitals far in the rear, missing the golden hour, the first 60 minutes after trauma when surgery is most likely to save a life. Bu...

About 95 percent of people are naturally immune to leprosy, and casual contact does not spread it, yet the disease drove societies to banish its victims to places like Molokai in Hawaii. This episode explains the real biology of Mycobacterium leprae and Mycobacterium lepromatosis, bacteria that cannot make their own energy and must live inside host cells. They invade Schwann cells, which insulate...

Lead may sit in modern bodies at levels up to a hundred times higher than in pre industrial people, and Beethoven's suffering is linked in this episode to cheap wine laced with it. The episode explains how the metal works as a systemic toxin: acute doses bring colic, shock, and burst red blood cells, while chronic exposure stiffens and scars blood vessels and kidneys, causes the blue Burton line o...

Laudanum is a tincture of about 10 percent powdered opium, roughly 1 percent morphine, dissolved in alcohol, and in the mid 19th century a bottle could cost less than gin. This episode traces the name to the 16th century alchemist Paracelsus, whose secret pain pill reportedly included crushed pearls, musk, and amber, and then to Thomas Sydenham in the 1660s, whose recipe called for opium, saffron,...

As a seven year old, Lady Mary had her name engraved on the drinking glasses of London's Kit Kat Club, yet her father denied her a formal education. This episode follows how she taught herself Latin in the family library, eloped with Edward Wortley Montagu rather than accept the marriage her father arranged, and survived smallpox in 1715 with a scarred face after the disease had killed her brother...

For centuries the kings and queens of England and France claimed they could cure the King's Evil, scrofula, a form of tuberculosis that swells the lymph nodes of the neck into disfiguring abscesses, simply by touching the sufferer. This episode explains why the claim held up: scrofula was rarely fatal and often went into remission on its own, so the monarch took credit for the immune system's work...

In the late 19th century, a blood transfusion could save a patient or make the blood clump, the kidneys fail, and the patient die, and no one knew why. This episode follows Karl Landsteiner, born in Vienna in 1868 to a Jewish family and left fatherless at six, who earned his medical degree in 1891 and then spent years studying chemistry in Würzburg, Munich, and Zurich. Back at the University of Vi...

Egyptian mummies were made by embalmers after death, but in Japan some Buddhist monks prepared their own bodies for preservation while still alive. This episode explains sokushinbutsu, the practice in which ascetics pushed austerity so far that their bodies mummified naturally, with no preservatives applied afterward. It grew out of Shugendo, a mountain religion taking shape around the seventh cen...

Alexander Fleming noticed a mold killing bacteria and published in 1929, but turning penicillin into a usable drug was the work of Howard Florey, a bootmaker's son born in an Adelaide suburb in 1898. This episode follows Florey from a family crisis that left him reliant on a state scholarship, through his refusal to start his Rhodes Scholarship at Oxford until he had finished his medical exams, to...

In 1796, while translating a treatise by the Scottish physician William Cullen, the German doctor Samuel Hahnemann rejected Cullen's claim that cinchona bark cured malaria because it was bitter. He swallowed the bark himself, developed fever, chills, and aching joints, and concluded that a drug cures a disease because it causes similar symptoms in a healthy person. This episode traces how that sin...

For thousands of years, efforts to stop decay produced brittle Egyptian mummies, specimens floating in gray formalin after 1896, or cloudy, fragile paraffin. In 1977, at an anatomy institute in Heidelberg, Germany, Gunther von Hagens developed plastination, a four step process that replaces the water and soluble fat in tissue with curable liquid polymers. This episode walks through each stage: fix...

The bezoar, from the Persian word for antidote, is a hardened mass of undigested hair and food from an animal's gut, yet for centuries it was prized as a stone that could neutralize any poison. This episode traces it from the 12th century physician Ibn Zuhr, credited with first documenting bezoars as antidotes, to the Mongol Empire, where the stones were used in shamanic rituals to summon storms....

For most of history, the best trained doctors blamed disease on miasma, a word tracing back to the ancient Greek for pollution: foul vapors rising from swamps, garbage, and rotting matter. This episode follows the long fight to replace that idea with germ theory. Thucydides saw people catch the plague of Athens from nursing the sick around 400 BC, and around 36 BC the Roman Marcus Terentius Varro...

Franz Anton Mesmer, born in 1734 near Lake Constance, studied medicine in Vienna and in 1766 wrote a dissertation on the influence of the planets on the human body that scholars say was largely lifted from Richard Mead's 1704 work. Marriage to the wealthy widow Anna Maria von Posch made him a patron of Viennese society, and legend has him hosting the premiere of 12-year-old Mozart's Bastien und Ba...