Category Science

WHEN WAS ANAESTHESIA FIRST USED?

Anaesthesia prevents pain signals from being received by the brain, so that the pain is not felt by the patient. Hundreds of years ago there were few ways to relieve a patient’s pain during surgery. Alcohol might be used, but it was not very effective. It was not until the nineteenth century that anaesthetic drugs began to be widely used. The first operation to be performed using a general anaesthetic was by an American surgeon, in 1842.

Anaesthesia refers to the practice of blocking the feeling of pain to allow medical and surgical procedures to be undertaken without pain.

 An ancient Italian practice was to cover a patient’s head with a wooden bowl and beat on it repeatedly until the patient lost consciousness. Presumably this method resulted in a number of side-effects the patient would not have found beneficial.

Opium and alcohol were regularly used to produce insensibility, both of which also had a number of negative side effects and neither could dull the pain completely. Few operations were possible and speed was the determinant of a successful surgeon. Patients were often tied or held down and the abdomen, chest and skull were effectively inoperable. Surgery was a last, and extremely painful, resort.

On October 16, 1846, an American dentist, William Morton, proved to the world that ether causes complete insensibility to pain during an operation performed in front of a crowd of doctors and students at the Massachusetts General Hospital. Morton instructed the patient to inhale the ether vapour and, once the patient was suitably sedated, a tumour was removed from his neck. The patient felt no pain. This demonstration transformed medical practice.

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WHAT WAS THE EARLIEST OPERATION?

Archaeologists have found skulls, dating from at least 10,000 years ago, that have holes drilled into them. Because bone has begun to grow around the holes, they were clearly made while the person was still alive. It is believed that this technique, called trepanning, was the first operation. It was probably done to relieve headaches or to let out evil spirits that were thought to be trapped inside the patient’s head.

The history of dental and surgical procedures reaches back to the Neolithic and pre-Classical ages. The first evidence of a surgical procedure is that of trephining, or cutting a small hole in the head. This procedure was practiced as early as 3000 BC and continued through the middle Ages and even into the Renaissance.  The initial purpose of trephining in ancient cultures is unknown; although some hypothesize it may have been used to rid the body of spirits. The practice was widespread throughout Europe, Africa, and South America. Evidence of healed skulls suggests some patients survived the procedure. Trephining continued in Ancient Egypt as a method of treating migraines. In South America, ancient Mayans practiced dental surgery by filling cavities with precious stones including jadeite, turquoise, quartz, and hematite, among others. It is supposed that these procedures were for ritual or religious purposes, rather than health or cosmetic reasons.

Ancient Greeks also performed some surgical procedures including setting broken bones, bloodletting, draining lungs of patients with pneumonia, and amputations. The Greeks had new, iron tools at their disposal, yet the risk of infection or death was still high. Hippocrates’ theory of four humors influenced medicine for hundreds of years. He claimed that the humors (black bile, yellow bile, phlegm, and blood which coincided with the elements earth, fire, water, and air, respectively) exist in the body, and bloodletting (or the draining of blood), among other procedures, balanced them. Ancient Roman physician Galen was heavily influenced by the Greeks. He served for three years as doctor to Roman gladiators and as the Emperor’s surgeon, gaining hands-on surgical experience. Romans continued with trephining, amputations, and eye surgery. Beginning in 900 AD, Al-Zahrawi, a famous Islamic surgeon, wrote books focused on orthopedics, military surgery, and ear, nose, and throat surgery, further influencing Islamic and Western medical practitioners.

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WHO WAS HIPPOCRATES?

Hippocrates is often described as “the father of modern medicine”. He was a Greek doctor, living in the fourth and fifth centuries BC , who taught that a doctor’s first duty is to his or her patient and that the aim must at all times be to try to do good rather than harm. When they qualify, many modern doctors take the Hippocratic Oath, promising to follow these principles throughout their careers.

Hippocrates was born around 460 BC on the island of Kos, Greece. He became known as the founder of medicine and was regarded as the greatest physician of his time.

He based his medical practice on observations and on the study of the human body. He held the belief that illness had a physical and a rational explanation. He rejected the views of his time that considered illness to be caused by superstitions and by possession of evil spirits and disfavor of the gods.

Hippocrates teaching Hippocrates held the belief that the body must be treated as a whole and not just a series of parts. He accurately described disease symptoms and was the first physician to accurately describe the symptoms of pneumonia, as well as epilepsy in children. He believed in the natural healing process of rest, a good diet, fresh air and cleanliness. He noted that there were individual differences in the severity of disease symptoms and that some individuals were better able to cope with their disease and illness than others. He was also the first physician that held the belief that thoughts, ideas, and feelings come from the brain and not the heart as others of his time believed.

Hippocrates traveled throughout Greece practicing his medicine. He founded a medical school on the island of Kos, Greece and began teaching his ideas. He soon developed an Oath of Medical Ethics for physicians to follow. This Oath is taken by physicians today as they begin their medical practice. He died in 377 BC. Today Hippocrates is known as the “Father of Medicine”.

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HOW HAS MACHINERY CHANGED FARMING?

Machinery has made it possible for the work of a dozen farm workers to be done twice as quickly by one worker. There are fewer people working on the land in developed countries than ever before. Machinery exacts a price from the environment as well, as hedges and ditches are removed to allow larger machines to work the enormous fields. Crops have been bred for the machine age, too. They need to ripen together, not over a period of time, so that machinery can harvest them in one operation.

Farm machinery, mechanical devices, including tractors and implements, used in farming to save labour. Farm machines include a great variety of devices with a wide range of complexity: from simple hand-held implements used since prehistoric times to the complex harvesters of modern mechanized agriculture.

The operations of farming for which machines are used are diverse. For crop production they include handling of residues from previous crops; primary and secondary tillage of the soil; fertilizer distribution and application; seeding, planting, and transplanting; cultivation; pest control; harvesting; transportation; storage; premarketing processing; drainage; irrigation and erosion control; and water conservation. Livestock production, which not so long ago depended primarily on the pitchfork and scoop shovel, now uses many complicated and highly sophisticated machines for handling water, feed, bedding, and manure, as well as for the many special operations involved in producing milk and eggs.

In the early 19th century, animals were the chief source of power in farming. Later in the century, steam power gained in importance. During World War gasoline- (petrol-) powered tractors became common, and diesel engines later became prevalent. In the developed countries, the number of farm workers has steadily declined in the 20th century, while farm production has increased because of the use of machinery.

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HOW CAN FISH BE FARMED?

Fishing in the open seas is expensive, dangerous and increasingly difficult as some fish stocks diminish. Fish farming involves using lakes, rivers and netted-off coastal areas to raise fish that can be harvested more easily. Freshwater fish and shellfish have been most success-fully farmed in this way. Many deep-sea fish require conditions that are impossible to recreate in managed waters.

Fish farming involves raising fish commercially in tanks or enclosures such as fish ponds, usually for food. It is the principal form of aquaculture, while other methods may fall under mariculture. A facility that releases juvenile fish into the wild for recreational fishing or supplement a species’ natural numbers is generally referred to as a fish hatchery. Worldwide, the most important fish species produced in fish farming are carp, tilapia, salmon, and catfish.

Demand is increasing for fish and fish protein, which has resulted in widespread overfishing in wild fisheries. China provides 62% of the world’s farmed fish. As of 2016, more than 50% of seafood was produced by aquaculture.

Farming carnivorous fish, such as salmon, does not always reduce pressure on wild fisheries. Carnivorous farmed fish are usually fed fishmeal and fish oil extracted from wild forage fish. The 2008 global returns for fish farming recorded by the totaled 33.8 million tons worth about $US 60 billion.

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WHICH ARE THE MOST COMMONLY FARMED ANIMALS?

Livestock is farmed chiefly to supply foods such as meat, eggs and milk, but also for leather, fur and wool. Animal by-products may also include glue, gelatin and fertilizer.

The term “livestock” refers to any domesticated, land-living animal that is raised to provide resources like meat, milk, eggs, and feathers, or to provide services like transportation or cultivation assistance. Buffalo, cows, ducks, goats, and horses are just a few examples of animals that fall into this broad category.

Livestock are raised around the globe, both on small scales—generally for subsistence or local trade—and in massive industrial operations supplying international markets. The sheer mass of these animals is hard to fathom: The combined weight of cattle, chickens, and pigs exceeds the weight of all wild animals and humans combined.

22.8 billion Chickens

Chickens are far and away the most numerous type of livestock on the planet. There are about 135 chickens for every cow—and three for every human.

Wild chickens are believed to have originated in northern China, and were eventually domesticated in Southeast Asia more than 5,000 years ago. China remains the world’s leading producer of chickens, claiming over 20 percent of the global chicken supply. However, the birds are now raised on every continent except Antarctica, where they are banned. Globally, chicken consumption is on the rise, outpacing the growth in consumption of other meats, like beef or pork. But growing demand for eggs has also contributed to chickens’ dominance.

1.5 billion Cattle

Cattle are the second most common livestock animal. Their domestication is thought to have occurred roughly 10,500 years ago, in what is now considered the Middle East.

Today, these animals are especially prevalent in South America, where they’re primarily raised for meat, and in India, where the animals are conversely valued for the dairy products they produce. Cows are revered in Hinduism, India’s majority religion, and most Indian states have regulation prohibiting, or at least regulating, the slaughter of cattle.

1.2 billion Sheep

Sheep are believed to be one of the first domesticated animals, and are common throughout the Old World. They’re especially prevalent in northeastern China, Central Asia, and North Africa, but are also raised intensively in New Zealand and Australia.

Although New Zealand is famous for having more resident sheep than people (with roughly six sheep for every person), it actually ranks third in terms of sheep per capita. Mongolia has a 10:1 ratio of sheep to humans, while the Falkland Islands, a British territory off the eastern coast of Argentina, boast more than 200 sheep per capita.

967 million pigs 

The sixth most common livestock animal is the humble pig, which is descended from the significantly more formidable wild boar. Pig production is localized to a few high-intensity areas in China, northern Europe, and the American Midwest. Nearly half of the world’s pigs are raised in China alone.

Excluding areas where pork is not customarily consumed—including North Africa, the Middle East, and other predominately Muslim regions—pig production is on the rise.

From 1960 to 2010, the number of pigs on the planet grew by 250 percent, while the size of individual pigs nearly doubled. This growth is attributed to increased demand for animal protein in the regions where pigs are already consumed.

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