Listening Section 4: Note & Table Completion: IELTS Academic 9990 (IELTS Academic)

Transcript-based practice (no audio).

Lecturer: Good morning, everyone. Today I want to take you beneath the waves to look at one of the ocean's most productive ecosystems: the kelp forest. Kelp forests grow in cool, nutrient-rich coastal waters, in water shallow enough for sunlight to reach the seabed. The dominant species along much of the Pacific coast is giant kelp, or Macrocystis pyrifera, and it's one of the fastest-growing organisms on the planet. Under good conditions it can grow as much as fifty centimetres a day.

Structurally, a kelp forest has three distinct layers. At the surface sits the canopy, made up of broad blades that float because each one carries small, gas-filled structures called pneumatocysts. Below that is the midwater layer, formed by long, flexible stalks called stipes. And at the base, kelp doesn't have roots the way a land plant does; instead it has a holdfast, a tangled, root-like structure that anchors the organism to rock on the seafloor.

A key relationship in this ecosystem is between kelp and sea urchins. Urchins graze on kelp, and their favourite target is the holdfast, chew through enough holdfasts and an entire kelp plant simply detaches and drifts away. Left unchecked, urchin populations can strip a rocky reef completely bare, creating what ecologists call an urchin barren.

What normally keeps urchin numbers in check is a keystone predator: the sea otter. Otters eat urchins voraciously, keeping numbers low enough for kelp forests to flourish. Historically, though, otters were hunted almost to extinction along the Pacific coast because of the fur trade during the eighteenth and nineteenth centuries, and without otters, urchin barrens spread across huge stretches of coastline.

Even after otter numbers partly recovered through legal protection, kelp forests remained vulnerable to sudden shocks. A striking example occurred in 2013, when sea star populations were struck by a wasting disease that devastated another major urchin predator, the sunflower sea star. With that predator gone, urchin numbers exploded, and vast stretches of kelp forest in California and Oregon were converted to barren rock within a few years.

To reverse this, marine biologists have turned to active restoration. Teams of divers now carry out manual culling, physically removing urchins from degraded reefs to give kelp spores a chance to re-establish. It's slow work, but kelp can recover quickly once grazing pressure eases.

Finally, this matters beyond the reef itself: kelp forests are exceptionally efficient at capturing atmospheric carbon dioxide and locking it away in ocean sediments, a process researchers now call blue carbon. Protecting kelp isn't just about biodiversity. It may also help mitigate climate change.

Complete the notes below. Write NO MORE THAN TWO WORDS AND/OR A NUMBER for each answer.

Kelp Forest Ecology. Lecture Notes

Species and growth

• Dominant species: giant kelp (Macrocystis pyrifera)
• Growth rate: up to (1) ______________ per day

Structure

• Buoyant structures on the canopy blades: (2) ______________
• Anchoring structure (not a true root): (3) ______________

Grazing pressure

• Bare reef caused by unchecked grazing: an (4) ______________
• Keystone predator that controls urchins: the (5) ______________
• Historical cause of that predator's decline: the (6) ______________
• 2013 event: sea stars struck by a (7) ______________

Restoration and value

• Diver-led restoration technique: (8) ______________
• Carbon captured and stored by kelp forests: known as "(9) ______________ carbon"

Transcript-based practice (no audio).

Lecturer: This morning we're going to look at one of medieval Europe's most unusual political creations: the Hanseatic League. The League wasn't really a state in the way we'd recognise one today. It was a confederation of merchant guilds and market towns that banded together, from roughly the thirteenth to the fifteenth centuries, to protect their shared trading interests along the coasts of the Baltic and North Seas.

Although the League had no single ruler, one city functioned as its de facto capital: Lübeck, on the German Baltic coast, where merchants from allied towns coordinated policy and pooled resources. Trade itself was organised around a network of overseas outposts the League established in major foreign ports; these outposts were known as kontors, and each one operated almost as a self-contained merchant colony, with its own warehouses, living quarters and legal privileges granted by the host city. The kontor in London, for instance, became known as the Steelyard, and it sat on the north bank of the Thames for several centuries, handling wool, cloth and metal goods moving between England and the continent.

Because there was no permanent bureaucracy holding the League together, major decisions were made at an occasional gathering of delegates from member towns called the Hanseatic Diet, which usually convened in Lübeck whenever a serious dispute or opportunity required a coordinated response. And because the League had no standing army either, its preferred tool for disciplining a rival city or a difficult foreign ruler wasn't warfare. It was a trade embargo. Simply cutting a port off from Hanseatic shipping could cripple its economy within months, which made the threat of an embargo remarkably effective diplomatic leverage.

The ships themselves typically carried a fairly predictable cargo: timber, furs, wax and grain moved west and south from the Baltic hinterland, while finished cloth and manufactured goods moved the other way. One of the most lucrative trades, though, was herring. Vast quantities were salted and shipped from fishing grounds off the southern Baltic coast. That trade eventually collapsed for reasons that had nothing to do with politics: sometime in the fifteenth century, the herring shoals themselves shifted their migration pattern away from the Baltic and into the North Sea, and Hanseatic merchants simply couldn't relocate their fishing operations fast enough to compete with rivals already established there.

Combined with the rise of centralised, tax-collecting nation-states and growing competition from Dutch and English merchants, this slow erosion of the League's economic base eventually proved fatal. The Hanseatic League never formally dissolved itself; it simply faded away, and historians usually mark 1669, the date of its last full Diet, as the effective end of nearly four centuries of Hanseatic dominance.

Complete the notes below. Write NO MORE THAN TWO WORDS AND/OR A NUMBER for each answer.

The Hanseatic League. Lecture Notes

Overview

• Type of organisation: a confederation of merchant guilds and market towns
• Region of activity: the Baltic and North Sea coasts
• De facto capital city: (1) ______________

Trading network

• Term for the League's overseas trading posts: (2) ______________
• London's trading post was known as the (3) ______________

Governance

• Central policy-making assembly: the Hanseatic (4) ______________
• Main economic weapon used against rival cities: a trade (5) ______________

Trade and decline

• Typical cargo carried west and south from the Baltic: timber, furs, wax and (6) ______________
• Cause of the herring trade's decline: fish shifted from the Baltic to the (7) ______________
• Year of the League's final full assembly: (8) ______________

Transcript-based practice (no audio).

Lecturer: Today's lecture looks at karst landscapes, terrain shaped almost entirely by the slow dissolution of soluble rock, most commonly limestone. Limestone is mainly calcium carbonate, and although it looks solid and permanent, it's actually vulnerable to a very ordinary chemical reaction. Rainwater absorbs carbon dioxide from the atmosphere as it falls, forming a weak carbonic acid, and when that slightly acidic water seeps into cracks in limestone bedrock, it gradually dissolves the rock along those fractures, widening them over thousands of years.

The most visible surface feature of a karst landscape is the sinkhole, a bowl-shaped depression that forms when dissolved rock beneath the surface collapses, sometimes gradually and sometimes, alarmingly, all at once. Karst regions are also known for their unusual drainage patterns: instead of flowing across the surface the way rivers normally do, a stream in karst terrain will often vanish abruptly into an opening called a swallow hole, continuing its journey entirely underground, sometimes for many kilometres, before re-emerging somewhere else as a spring.

It's this underground drainage that carves out cave systems, and inside those caves, the same dissolving process runs in reverse. As mineral-rich water drips from a cave ceiling, a tiny amount of calcite is left behind each time a drop evaporates, and over centuries this builds a downward-growing icicle-like formation called a stalactite. Where the drips land on the cave floor, the same mineral accumulates upward instead, forming a stalagmite. Given enough time, a stalactite and a stalagmite can even meet in the middle and fuse into a single column. Collectively, geologists refer to all of these mineral deposits (stalactites, stalagmites, and related shapes) as speleothems.

On the surface, dissolution can also produce a striking feature called a limestone pavement: a flat expanse of bedrock that chemical weathering has carved into a grid of rectangular blocks. The blocks themselves are called clints, and the narrow, often deep fissures separating them are called grikes. These grikes frequently shelter plant species that would otherwise struggle to survive fully exposed on open pavement.

Finally, I want to flag a serious practical concern. Karst aquifers supply drinking water to a substantial share of the world's population, but they are unusually vulnerable to contamination. In most rock types, water percolating downward is naturally filtered as it passes slowly through layers of soil and sediment. In karst terrain, however, water often travels rapidly through open fractures and cave conduits with little or no filtration, meaning a pollutant introduced at the surface can reach, and contaminate, a drinking water supply within hours rather than years.

Complete the notes below. Write NO MORE THAN TWO WORDS AND/OR A NUMBER for each answer.

Karst Landscapes. Lecture Notes

Formation

• Main rock type shaped by karst processes: (1) ______________
• Weak acid formed when rainwater absorbs carbon dioxide: (2) ______________

Surface features

• Bowl-shaped surface depression: (3) ______________
• Opening where a stream disappears underground: (4) ______________

Cave formations

• Downward-growing cave formation: (5) ______________
• Upward-growing cave formation: (6) ______________
• Collective term for cave mineral formations: (7) ______________

Limestone pavement

• Fissures separating pavement blocks: (8) ______________

Water supply

• Main risk to karst aquifers: (9) ______________

Transcript-based practice (no audio).

Lecturer: In this lecture I want to explain how modern engineers protect buildings from earthquakes using a technique called base isolation. The basic idea is refreshingly simple: instead of fixing a structure rigidly to the ground and relying on the frame's strength to survive shaking, engineers insert a layer of flexible devices, called isolators, between the foundation and the structure above. When the ground shakes violently, these isolators allow the building to move largely independently of the ground, so far less seismic force reaches the structure itself.

There are two common types of isolator. The first is the lead-rubber bearing, a stack of alternating rubber and steel plates with a solid lead core running through the centre. The rubber layers let the bearing flex sideways, absorbing horizontal motion, while the lead core deforms plastically during shaking, dissipating energy as heat. The second common type is the friction pendulum bearing, which works quite differently: it uses a curved sliding surface, so the building literally slides across a shallow concave dish during an earthquake, and gravity guides the structure back to its original position once the shaking stops.

What both approaches achieve, from an engineering standpoint, is a period shift. Every building has a natural vibration period, the rate at which it sways if disturbed, and ordinary earthquake motion shakes a conventional, fixed-base building most violently at that period. By adding flexible isolators, engineers effectively lengthen the building's natural period, shifting it away from the ground's strongest shaking frequencies, which dramatically reduces the forces the structure actually experiences.

Of course, allowing a building to move introduces practical complications. Because the base can shift sideways by a significant distance during a major quake, designers must leave a seismic gap around the entire perimeter of the building, a clear space preventing collisions with neighbouring buildings or utility lines. For the same reason, every pipe and cable crossing that isolation joint has to be flexible, able to stretch without rupturing as the building shifts.

One of the best-known examples of this approach is the retrofit of San Francisco City Hall, completed in the 1990s, where isolators were installed beneath the historic building without altering its exterior appearance. Base isolation isn't cheap, it adds noticeably to a project's upfront cost, but that additional expense is usually offset by dramatically reduced repair costs and downtime after a major earthquake, since isolated buildings suffer far less structural damage.

Complete the notes below. Write NO MORE THAN TWO WORDS AND/OR A NUMBER for each answer.

Earthquake-Resistant Design: Base Isolation. Lecture Notes

Basic principle

• Devices placed between the foundation and the structure: (1) ______________

Isolator types

• First isolator type: the (2) ______________ bearing
• Second isolator type: the (3) ______________ bearing

Engineering effect

• Effect both isolator types achieve on the building's vibration: a (4) ______________

Practical requirements

• Clear space required around the building's perimeter: a (5) ______________
• Pipes and cables crossing the isolation joint must be: (6) ______________

Example and cost

• City containing a well-known base-isolation retrofit: (7) ______________
• Base isolation increases a project's (8) ______________

Transcript-based practice (no audio).

Lecturer: Today's topic is habit formation (how a behaviour that once required real conscious effort eventually becomes something we do almost without thinking. Psychologists commonly describe this process using a three-part model called the habit loop. The first part is the cue, a trigger) a time, place, emotional state or preceding action. That signals the brain a particular behaviour is available. The second part is the routine itself, the actual behaviour that follows. And the third part is the reward, some form of positive outcome that reinforces the connection between that cue and that routine, making it more likely to fire again next time the same cue appears.

What's happening in the brain during this process is genuinely interesting. Early on, while a behaviour is still deliberate, it's largely controlled by the prefrontal cortex, the region responsible for conscious planning and decision-making. But as the cue-routine-reward sequence repeats, control gradually shifts to a deeper brain structure called the striatum, part of a group of structures known as the basal ganglia. Once the striatum takes over, the entire sequence of actions effectively compresses into a single automatic unit, a process researchers call chunking, and the behaviour can then run with minimal conscious input.

This has an interesting side effect: once a habit is fully chunked, the cue alone is often enough to trigger the routine, even when the reward that originally reinforced it is no longer relevant or even desired. This explains a common phenomenon known as a habitual slip. For example, someone who has just changed jobs might still automatically turn the car toward their old workplace, because years of driving that route had already fully chunked the behaviour.

So how long does it actually take to build a new habit? There's a widely repeated myth that any new behaviour becomes automatic after twenty-one days, but that figure has no solid research basis. A frequently cited study led by the researcher Phillippa Lally tracked participants forming everyday habits and found the true time ranged enormously, from as little as eighteen days up to two hundred and fifty-four days, with an average of around sixty-six days before a behaviour reached full automaticity.

One practical technique that takes advantage of the habit loop is called habit stacking, where you deliberately attach a new, desired behaviour to the cue of an already well-established habit. For instance, doing a set of stretches immediately after brushing your teeth, since brushing your teeth already happens reliably every single day. Because the existing habit's cue is already firmly wired in, the new behaviour gets to piggyback on a trigger that doesn't need to be built from scratch.

Complete the notes below. Write NO MORE THAN TWO WORDS AND/OR A NUMBER for each answer.

Habit Formation. Lecture Notes

The habit loop

• Trigger: (1) ______________
• Behaviour that follows the trigger: (2) ______________
• Reinforcing outcome: (3) ______________

Brain basis

• Region responsible for early, deliberate control: (4) ______________
• Structure that takes over once a behaviour is automatic: (5) ______________
• Term for compressing a sequence of actions into one automatic unit: (6) ______________

A common problem

• Performing a habit unintentionally in the wrong context: a (7) ______________

Timing research

• Popular but inaccurate myth about habit-formation time: (8) ______________
• Average time found by Lally's research: (9) ______________

A practical technique

• Attaching a new habit to an existing habit's cue: (10) ______________

Transcript-based practice (no audio).

Lecturer: Good morning, everyone. Today I want to talk about repair cafés. An idea that's quietly reshaping how ordinary households deal with broken possessions, and one that economists have started paying close attention to.

Let me start with some background. The first repair café opened in Amsterdam in 2009, founded by a former environmental journalist who wanted to challenge the throwaway culture of modern consumer goods. The model was simple: volunteers with practical skills (electricians, seamstresses, carpenters) would give up a few hours a month to fix items that people brought in for free, rather than have them thrown away.

Within a decade, the concept had spread well beyond the Netherlands, and today there are more than two thousand repair cafés operating across Europe alone, most run entirely by unpaid volunteers.

Now, from an economic standpoint, three features make repair cafés particularly interesting. First is the funding model. Most events aren't run for profit at all; instead they typically rely on small grants from the local council to cover venue hire and basic tools, supplemented by voluntary donations from grateful visitors on the day.

Second is the question of success rate. Studies tracking outcomes across several countries found that volunteers are able to successfully repair the item on the spot in roughly seventy percent of cases. A surprisingly high figure given how varied the items brought in can be.

Third, and this is really the crux of the matter for economists, is what repair cafés reveal about a market failure. The single biggest obstacle volunteers report is not a lack of skill, but the unavailability of spare parts. Manufacturers frequently stop producing replacement components only a few years after a product is released, a practice critics call planned obsolescence.

What items come through the door most often? Perhaps unsurprisingly, small electrical appliances (toasters, kettles, lamps) make up the largest category by far, followed by clothing and textiles needing mending, then furniture.

A typical session at a repair café lasts about two hours, and most locations report an average attendance of around twenty-five visitors per session, though this can double around the winter holiday period when broken gifts and worn-out coats are common.

Looking ahead, several city governments are now exploring whether to offer tax relief for professional repair businesses, hoping to extend the repair café model's success into the formal economy as well.

Complete the notes below. Write NO MORE THAN TWO WORDS AND/OR A NUMBER for each answer.

REPAIR CAFÉS: LECTURE NOTES

Origins

• First repair café opened in 1 __________ (year)
• City where the idea began: 2 __________
• Founder's previous occupation: 3 __________

Growth

• Number of repair cafés now running across Europe: over 4 __________

How they operate

• Main source of funding: 5 __________ grants
• Average on-the-spot repair success rate: 6 __________
• Most commonly reported obstacle for volunteers: lack of 7 __________
• Most frequent category of items brought in: 8 __________

Transcript-based practice (no audio).

Lecturer: This week we're turning to transhumance, the seasonal movement of livestock between two distinct grazing areas, typically a lowland winter pasture and a highland summer pasture. Anthropologists have long been interested in transhumance not just as a farming technique, but as a social system that shapes kinship, land rights, and community identity.

The practice has existed for thousands of years, but some of the best-documented modern case studies come from the Pyrenees, on the border between France and Spain, where entire villages still organise their yearly calendar around the movement of sheep and cattle to high mountain pastures each summer.

One of the central anthropological questions is how access to shared pasture is regulated without a formal legal deed to the land. Fieldwork in the region has shown that grazing rights are typically inherited through the male line, passed down within extended family groups, and disputes are usually settled not in court but by a locally elected pasture committee.

The seasonal move itself, often called the "transhumance," usually takes place over roughly two weeks each way, with herders walking the flock along traditional droving routes that in some valleys are centuries old and are legally protected from development.

Now, one figure worth noting: a survey conducted across three Pyrenean valleys found that the number of families still practising full transhumance had fallen from around four hundred in the 1960s to fewer than sixty today, a decline of more than eighty-five percent.

Why the steep drop? Researchers point to three main factors. First, younger generations increasingly move to cities for education and employment, breaking the chain of skills passed from parent to child. Second, rising land prices in lowland valleys have made it more profitable to sell winter pasture for holiday housing than to keep it for livestock. Third, and perhaps most significantly, EU agricultural subsidies were, for many years, calculated in a way that favoured large, sedentary farms over small mobile herds, though this policy has recently been revised.

Despite the decline, there's renewed interest from an unexpected source: rural tourism. Several valleys now run guided "transhumance walks," inviting visitors to accompany the herders for a day, generating income that is helping a handful of young families return to the practice.

I'll be posting the reading list for next week's seminar, which focuses on comparable pastoral systems in the Atlas Mountains, on the course page.

Complete the notes below. Write NO MORE THAN TWO WORDS AND/OR A NUMBER for each answer.

TRANSHUMANCE: LECTURE NOTES

Location of case studies

• Region discussed today: the 1 __________
• Villages there move livestock to 2 __________ pastures each summer

Land & inheritance

• Grazing rights are usually inherited through the 3 __________ line
• Disputes are settled by a locally elected 4 __________

The seasonal move

• Each leg of the move takes about 5 __________
• Old droving routes are legally protected from 6 __________

Decline in numbers

• Families still practising fell from around 400 in the 1960s to fewer than 7 __________ today
• One driver of the decline: rising 8 __________ prices in lowland valleys

New trend

• Tourism income now comes from guided 9 __________

Transcript-based practice (no audio).

Lecturer: Today's lecture is about brown dwarfs, sometimes nicknamed "failed stars," because they sit in an awkward middle ground between the largest planets and the smallest true stars.

To understand why, we need to talk about mass. A brown dwarf typically has a mass somewhere between about thirteen and eighty times the mass of Jupiter. Below that lower boundary, an object is generally classified as a planet; above the upper boundary, it becomes massive enough to fuse ordinary hydrogen in its core and shine as a genuine star.

Brown dwarfs do undergo one type of nuclear fusion, though: they can briefly fuse deuterium, a heavier isotope of hydrogen, early in their lives. This produces a faint glow, but nowhere near the sustained brightness of a main-sequence star, which is why brown dwarfs are notoriously difficult to detect.

The first confirmed brown dwarf, named Teide 1, wasn't found until 1995, more than three decades after the category was first proposed theoretically. It was discovered in the Pleiades star cluster using ground-based telescopes sensitive to infrared light, since brown dwarfs radiate most of their energy at infrared wavelengths rather than visible ones.

Since then, astronomers have organised brown dwarfs into three spectral classes, based on decreasing temperature: L, T, and Y, with Y-class objects being the coolest and dimmest, some barely warmer than a household oven.

One landmark discovery came in 2013, when astronomers identified a pair of brown dwarfs, now called Luhman 16, orbiting each other just six point five light years from Earth, making it the third-closest star system to our own Sun.

What's particularly exciting to atmospheric scientists is that brown dwarfs appear to have genuine weather. Observations of changing brightness over time suggest cloud bands of hot silicate or iron droplets that shift and break apart, not unlike storm systems on Jupiter, though far more extreme.

Large-scale surveys have been essential to this field. The Two Micron All Sky Survey, usually abbreviated to 2MASS, catalogued thousands of candidate objects in the late 1990s and remains a key reference dataset for brown dwarf research today.

Looking forward, the James Webb Space Telescope's infrared instruments are expected to characterise brown dwarf atmospheres in far greater detail over the coming decade, potentially settling the ongoing debate about where exactly the line between a large planet and a small brown dwarf should be drawn.

Complete the notes below. Write NO MORE THAN TWO WORDS AND/OR A NUMBER for each answer.

BROWN DWARFS: LECTURE NOTES

Definition

• Minimum mass to count as a brown dwarf: about 1 __________ Jupiter masses
• Above the top of this range, an object can fuse ordinary 2 __________ and becomes a true star

Fusion

• Brown dwarfs can briefly fuse 3 __________ early in their lives

Discovery

• First confirmed brown dwarf, Teide 1, found in 4 __________ (year)
• Found using telescopes sensitive to 5 __________ light

Nearby system

• Luhman 16 lies about 6 __________ light years from Earth

Key survey

• Large-scale survey used: 7 __________

Transcript-based practice (no audio).

Lecturer: This morning I want to trace the story of one particular pigment, ultramarine, because its history tells us as much about trade and economics as it does about art.

Ultramarine is made by grinding lapis lazuli, a deep blue semi-precious stone. For most of history, essentially all of the world's usable lapis lazuli came from a single source: a cluster of mines in a remote valley in what is now northeastern Afghanistan, known as the Sar-e-Sang mines.

Getting the raw stone from those mountains to a European workshop involved a journey of thousands of miles along overland trade routes, which is really why the pigment carries its name. "ultramarine" literally means "beyond the sea," referring to the sea it had to cross to reach Europe.

Extracting a usable pigment from the raw stone was also remarkably laborious. Simply grinding the rock produces a dull grey powder, because the blue mineral, lazurite, is mixed with impurities. To purify it, workshops developed a technique of kneading the powder into a paste of wax, oil and resin, then repeatedly working that paste in a dilute lye solution, a process painters at the time called "walking" the pigment, until the pure blue particles separated out.

Because of the cost of the raw material and the labour of this purification process, by the fourteenth century, ultramarine had become, ounce for ounce, more expensive than gold. Painters and their patrons treated it accordingly: contracts for altarpieces frequently specified, in writing, exactly which figures were permitted to be painted in ultramarine, almost always reserved for the robes of the Virgin Mary, as a mark of her importance.

This changed dramatically in the nineteenth century. In 1824, a French scientific society, the Société d'Encouragement, offered a cash prize to anyone who could produce a synthetic version of the pigment at a fraction of the natural cost. Two years later, in 1826, a French chemist named Jean-Baptiste Guimet succeeded, and claimed the prize.

Synthetic ultramarine was chemically almost identical to the natural pigment but could be manufactured cheaply and in bulk. Within a generation, the price of the natural, stone-ground version collapsed, and by the end of the century it had all but disappeared from working artists' studios, surviving mainly as a historical curiosity used by a handful of conservators restoring older paintings.

So what began as one of the rarest and most expensive materials available to a painter ended up, within fifty years, as one of the cheapest. A striking reminder of how a single laboratory discovery can reshape an entire artistic tradition.

Complete the notes below. Write NO MORE THAN TWO WORDS AND/OR A NUMBER for each answer.

ULTRAMARINE: LECTURE NOTES

Source

• Made by grinding 1 __________, a semi-precious stone
• Main historical source: the Sar-e-Sang mines in 2 __________

Name & trade

• Name means "beyond the 3 __________"

Purification

• Raw grinding alone produces a dull 4 __________ powder
• Powder purified by kneading into a paste of wax, oil and 5 __________
• This purification process was known as 6 __________ the pigment

Cost & status

• By the 14th century, more expensive than 7 __________ by weight
• Almost always reserved for the robes of 8 __________

The synthetic breakthrough

• Prize offered by the Société d'Encouragement in 9 __________ (year)
• Synthetic version successfully produced by chemist 10 __________ in 1826

Transcript-based practice (no audio).

Lecturer: Close your eyes for a second and touch your nose with your index finger. Most people manage this instantly, without looking, and that's thanks to a sense most of us never think about: proprioception, the body's internal awareness of the position and movement of its own limbs.

The term itself was coined in 1906 by the British physiologist Charles Scott Sherrington, who combined the Latin words for "one's own" and "to receive" to describe this hidden sensory system.

Proprioception depends on three main types of receptor. Muscle spindles, embedded within the muscle tissue itself, detect changes in muscle length and the speed of that change. Golgi tendon organs, located where muscle meets tendon, monitor the tension generated by a contracting muscle. And joint receptors, found in the tissue surrounding each joint, register the angle and pressure at that joint.

Together, these three systems send a constant stream of signals to the brain, allowing us to know where our limbs are and how they're moving without needing to look at them, which is exactly why the nose-touching test works with your eyes shut.

Clinicians often assess this system using something called the Romberg test, which simply asks a patient to stand with their feet together and their eyes closed. A healthy proprioceptive system keeps a person steady; significant swaying or loss of balance can indicate a proprioceptive deficit.

One of the most striking cases in the medical literature is that of a British patient who, after a rare viral illness in 1971, permanently lost all proprioceptive and touch sensation from the neck down, despite his muscles themselves remaining undamaged. He had to relearn to walk and move almost entirely by using vision to consciously monitor and correct every movement, a strategy that collapses instantly in darkness.

This case has become central to research on sensory substitution and rehabilitation, because it demonstrates just how much conscious effort the brain normally saves us by handling proprioceptive feedback automatically, below the level of awareness.

More recently, sports scientists have become particularly interested in proprioception because athletes with well-trained proprioceptive systems recover faster from ankle and knee injuries and are significantly less likely to suffer repeat sprains. This has led to a rise in balance-board and wobble-cushion training as a standard part of injury-prevention programmes for footballers and other athletes at every level.

Engineers are also getting involved: several labs are now developing wearable sensors designed to mimic proprioceptive feedback for use in advanced prosthetic limbs.

Complete the notes below. Write NO MORE THAN TWO WORDS AND/OR A NUMBER for each answer.

PROPRIOCEPTION: LECTURE NOTES

Definition

• Term coined in 1 __________ (year)
• Coined by physiologist 2 __________

Receptors

• 3 __________ detect changes in muscle length
• Golgi tendon organs monitor 4 __________ generated by a contracting muscle
• Joint receptors register angle and 5 __________ at a joint

Testing

• Clinicians assess proprioception using the 6 __________ test

Case study

• British patient lost proprioception after a viral illness in 7 __________ (year)

Applications

• Well-trained athletes have fewer repeat 8 __________