AcharyaChanakya/simple-wikipedia huggingface dataset:
A "heart beat" is when the heart muscle "contracts". This means the heart pushes in and this makes the chambers smaller. This pushes blood out of the heart and into the blood vessels. After the heart contracts and pushes in, the muscle "relaxes" or stops pushing in. The chambers get bigger and blood coming back to the heart fills them.
When the heart muscle contracts (pushes in) it is called "systole". When the heart muscle relaxes (stops pushing in), this is called "diastole". Both atria do systole together. Both ventricles do systole together. But the atria do systole "before" the ventricles. Even though the "atrial systole" comes before "ventricular systole", all four chambers do diastole at the same time. This is called "cardiac diastole"
The order is: atrial systole → ventricular systole → cardiac diastole. When this happens one time, it is called a "cardiac cycle".
Systole (when the heart squeezes) happens because the muscle cells of the heart gets smaller in size. When they get smaller we also say they "contract". Electricity going through the heart makes the cells contract. The electricity starts in the "sino-atrial node" (acronym SA Node) The SA Node is a group of cells in the right atria. These cells start an "electrical impulse". This electrical impulse sets the rate and timing at which all cardiac muscle cells contract. This motion is called 'atrial systole'. Once electrical impulse goes through the "atrio-ventricular node" (AV Node). The AV Node makes the impulse slow down. Slowing down makes the electrical impulses get to the ventricles later. That is what makes the ventricular systole occur "after" atrial systole, and lets all the blood leave the atria before ventricle contracts ("meaning squeeze").
After the electrical impulse goes through the AV Node, the electrical impulse will go through the "conduction system" of the ventricle. Conduction means heat or electricity traveling through something. This brings the electrical impulse to the ventricles. The first part of the conduction system is the "bundle of His". "His" is named for the doctor (Wilhelm His, Jr) who discovered it. Bundle means strings or wires grouped together in parallel. Once the bundle ("meaning a group of strings or wires going in parallel directions") goes through the ventricle muscle, it divides into two "bundle branches", the left bundle branch and the right bundle branch. The left bundle branch travels to the left ventricle and the right bundle branch travels to the right ventricle. At the end of the bundle branches, the electrical impulse goes into the ventricular muscle through the Purkinje Fibers. This is what makes ventricle contraction take place and makes ventricular systole.
The order is:
Sino-Atrial Node → Atria (systole) → Atrio-Ventricular Node → Bundle of His → Bundle branches → Purkinje Fibers → Ventricles (systole)
ECG is an acronym for ElectroCardioGram. It is also written EKG for ElectroKardioGram in German. The ECG shows what the electricity in the heart is doing. An ECG is done by putting electrodes on a person's skin. The electrodes see the electricity going through the heart. This is written on paper by a machine. This writing on the paper is the ECG.
Doctors learn about the person's heart by looking at the ECG. The ECG shows some diseases of the heart like heart attacks or problems with the "rhythm" of the heart (how the electricity goes through the heart's conduction system.)
The ECG shows atrial systole. This is called a P-wave. Then ventricular systole happens. This is called the QRS or QRS-complex. It is called a complex because there are three different waves in it. The Q-wave, R-wave, and S-wave. Then the ECG shows ventricular diastole. This is called the T-wave. Atrial diastole happens then too. But it is not seen separate from ventricular diastole.
The PR-Interval is the space between atrial systole (P) and ventricular systole (QRS). The QT-Interval is from when the QRS starts to when the T ends. The ST-segment is the space between the QRS and T.
Heart disease is a general term that means that the heart is not working normally. Babies can be born with heart disease. This is called congenital heart disease. If people get heart disease later, it is called acquired heart disease. Most heart disease is acquired.
The three most common types of acquired heart disease are:
A person can have heart disease and not feel sick. Some people with heart disease have symptoms. This is when there are changes or pain in the body to show a disease is there. Some symptoms of heart disease are:
Heart disease is the biggest killer of both men and women in the United States, England, Wales, and Canada. For example, heart disease causes 4 out of every 10 deaths in the United States. This is more than all kinds of cancer put together. Also, one person dies of heart disease about every minute in the United States alone.
Congenital heart disease refers to a form of heart problem that starts before birth (congenital). Congenital heart disease includes a large number of conditions. The formation of the heart before birth is very complex and is sometimes abnormal. For example, if a part of the main artery that comes from the heart is narrowed, that is called coarctation of the aorta. There may be holes inside the heart which keep the blood from flowing normally inside the heart. Other congenital heart problems are caused by abnormal heart valves. In some cases, congenital heart problems are discovered at birth. Other times the problems may not be detected until the person is an adult
North Dakota is a state in the United States. 672,591 people lived in North Dakota in the year 2010. The capital and seat of government is Bismarck.
North Dakota is south of Manitoba and Saskatchewan, east of Montana, north of South Dakota, and west of Minnesota. Manitoba and Saskatchewan are provinces - part of Canada. Montana, South Dakota, and Minnesota are other states in the United States.
North Dakota is not close to any big bodies of water (oceans or seas). Because of this, temperatures in North Dakota are "very" hot in the summer and "very" cold in the winter. In the summer, there are sometimes "strong" thunderstorms. These storms can have tornadoes and hail.
Before European people came, Native American people lived in the area now called North Dakota. One important tribe was the Mandan.
North Dakota was one of the last US states to be "settled". (To have people go there to make homes and live.) On November 2, 1889, North Dakota (and South Dakota) became part of the United States.
Most of the economy is based on agriculture. The most important agricultural crops are durum, a type of wheat, which is grown all across the state. In the Red River Valley, there is more rain, and maize (corn) and sugar beets are grown as well. In the Badlands, there is less rain, and more cattle are raised than crops.
North Dakota has the only bank in the United States that is "owned" by the state. The Bank of North Dakota is where all of the money from all government agencies is held. Most banks in the United States are guaranteed by the FDIC (acronym for Federal Deposit Insurance Corporation.) The FDIC guarantees that people will not lose money if a bank fails. But the Bank of North Dakota is insured by the "state" of North Dakota.
LGBT is an initialism that means lesbian, gay, bisexual, and transgender. It refers to the a community of people who are not heterosexual or cisgender. The initialism has been taken up by many sexuality and gender identity-related community centers.
Before the "sexual revolution" of the 1960s, there was no neutral word or group of words for people who were not heterosexual.
The word "homosexual" started being used in America to describe sexual orientations that were not heterosexual. However, this word began to have bad connotations, as many people thought that it sounded like a condition or mental illness, and therefore the word "homophile" was used instead. After that, the word "gay" replaced the word "homophile" in the 1970s.
As lesbians became more public about their sexuality in the 1970s, the group of words "gay and lesbian" was often used, and a phase of lesbian feminism started. This meant that certain lesbian feminist groups separated because did not have knowledge of if they should put feminism or gay rights first.
Lesbian feminists viewed the separation between "butch" and "femme" in mainstream gay (male) culture of the time in the same way that they viewed the separation in society over gender roles between men and women. They saw these ideas as patriarchal and did not want to join the mainstream gay rights movement because of what they saw as the chauvinism of gay men, and refused to take up their cause. Many lesbians who were not lesbian feminists saw this as not giving help to the gay rights movement.
This was followed by many bisexual and transgender people wanting to be seen as respected groups in the LGBT community. Before gender reassignment surgery was massively improved in later years, transgender people had a hard time being accepted. Still, they fought for their rights, and were greatly boosted when plastic surgery and hormone surgery helped them to be accepted as the gender they identify with.
After the Stonewall riots, there was a change in points of view among the gay and lesbian community. Many gays and lesbians became less accepting of bisexual and transgender persons in general. Many gays and lesbians thought that transgender people were acting out stereotypes and that bisexuals were actually gay, but in too much fear to "come out of the closet". This separation still exists today, and it only became common to speak of all members of the LGBT community with equal respect in the trouble for LGBT rights in the late 1990s.
Some people who are LGBT may not "come out", as they may be a target of discrimination or prejudice, such as homophobia or transphobia. Many countries have discriminatory laws against LGBT people, some even giving out the death penalty for being gay or bisexual.
When not including transgender persons in general, the acronym is sometimes shortened to just ""LGB"".
Many other letters are added to the acronym, so much so that it has been described as an "alphabet soup" by some. A few of the other letters added are:
Not everyone is in agreement what should or should not be covered in the acronym, or which order the letters should go in.
The group of words gender and sexual diversity (GSD) has been shown as a different option to LGBT by some, as it is seen as more inclusive and less limiting.
SGL (same-gender loving) is sometimes used among gay male African Americans as a way of distinguishing themselves from what they think of as white LGBT groups of persons.
MSM (men who have sex with men) is used to describe men who have sex with other men without having relation to their sexual orientation, often in a medical context.
WSW (women who have sex with women) is the opposite of MSM. It includes all women who have sex with women.
Rainbow flag
The rainbow flag is a multi-colored flag consisting of stripes in the colors of the rainbow that is displayed in many cultures around the world as a sign of diversity and inclusiveness. The German pastor Thomas Müntzer used a rainbow flag as a symbol of solidarity as early as the German Peasants' War of the 16th century. It is common as a symbol of the Peace movement, first used this way in a peace march in Italy in 1961.
In 1924 the Indian spiritual teacher Meher Baba designed a rainbow flag. It is flown each year near his tomb near Ahmednagar, India during the anniversary of his death on January 31, 1969. Baba explained the symbolism, saying, "The colors in the flag signify man's rise from the grossest of impressions of lust and anger – symbolized by red – to the culmination in the highest state of spirituality and oneness with God – symbolized by sky blue."
The rainbow is also a symbol in the Christian and Jewish Bible. It shows God's promise to Noah and his family to never cover the world in water again.
A Christian movement known as Cursillo, founded in 1944, uses these traditional rainbow symbols, including flags. Their version can have 5 to 7 colors, with red at the top, blue or purple at the bottom, and the Spanish words "De Colores!" ("of colors") in large letters on the front.
This rainbow flag in Italy was first used in a peace march in 1961, inspired by similar multi-coloured flags used in demonstrations against nuclear weapons. The most common variety has seven colours, purple, blue, light blue, green, yellow, orange and red, and is emblazoned in bold with the Italian word "PACE", meaning "peace".
It has also been the symbol of the LGBT (lesbian, gay, bisexual, and transgender) community since it's creation in 1978. It is also called the 'Pride Flag.' The flag was created by Gilbert Baker of San Francisco, California in 1978.
Dualism is the idea or theory that something (an object, an idea or the whole world) is split into two parts. These parts are separate from each other, and the thing cannot be divided up in any other way. The idea or theory that something cannot be split into any parts is called monism. The idea that something can be split into many parts is called pluralism.
In philosophy there are many kinds of dualism.
Dualism is also a common sense idea. For example, it is a form of dualism to say that a thing is either hot or cold, good or bad, mine or somebody else's, with no allowance for possible states in between.
In theology, dualism may also refer to "duotheism", "bitheism" or "ditheism". This the doctrine or belief that there are two independent divine beings or eternal principles, one good and the other evil. Examples of ditheism include Zoroastrianism, Wicca and Marcionism. Although the Bible mentions Satan, this is not ditheism as he is not equal to God, but merely an angel. (See Epistle of Jude, verse 6). Ditheism is not the same as dualism, but they are similar. Ditheism implies (at least) two gods, while moral dualism does not imply any "-theism" (belief in a god) whatsoever.
Vomiting, also called puking, is emptying the contents of stomach through mouth. It can be either food or liquid in the stomach. It can be from infection, contaminated food or drink (food poisoning), foul smells or foul-tasting food, the brain being injured, a block in the small intestines so food and liquid cannot go through, too much alcohol or other drugs. Also, people can make themselves vomit (self-induced) which is called purging. Usually people who have eaten or drunk poison are made to vomit any residual (leftover) poison off. Excessive vomiting may lead to dehydration, which can be dangerous, if not fatal as it will shut down a person's organs and twist the intestines.
Ancient Greece was a large area in the northeast of the Mediterranean Sea, where people spoke the Greek language. It was much bigger than the nation of Greece we know today. It was the civilization of Greece, from the archaic period of the 8th/6th centuries BC to 146 BC. The period ended with the Roman conquest of Greece in the Battle of Corinth.
For most of this time, the Greeks did not have a single government or ruler. They did, however, have a common language and culture. The Greek language is an Indo-European language.
There were a number of city states, each with its own constitution. Athens, Sparta and Corinth are examples of city-states. Some had kings, and some, like Athens, had a form of democracy. As time went on, the most-powerful cities collected other cities into groups known as "leagues". This applied to many of the Greek colonies in Asia Minor, most of which had close ties to one or another of the three big cities.
In the middle of this period, there was Classical Greece, which flourished during the 5th to 4th centuries BC. Athenian leadership successfully repelled the threat of Persian invasion in the Greco-Persian Wars. The Athenian golden age ends with the defeat of Athens at the hands of Sparta in the Peloponnesian War in 345Bc
In the last, Hellenistic, period, Greece was unified by the conquests of Alexander the Great. The city-states continued, under the overall influence of Macedonia.
Greek culture had a powerful influence on the Roman Empire, which carried a version of it to many parts of the Mediterranean region and Europe. In this way, classical Greece was part of the foundation of Western civilization. Greek was also the language, and partly the culture, of the Byzantine Empire.
The history of Greece went through these stages:
In the 8th century B.C., the Greeks learned how to read and write a second time. They had lost literacy at the end of the Mycenaean culture, as the Mediterranean world fell into the Dark Ages. The Greek Dark Ages (~1100 BC–750 BC), or Bronze Age collapse, is a period in the history of Ancient Greece and Anatolia from which there are no written records, and few archaeological remains.
The Greeks learned about the alphabet from another ancient people, the Phoenicians. They made some adjustments to it. In particular, the Greeks introduced regular letters for vowels, which was necessary for their language. Their alphabet was, in turn, copied by the Romans, and much of the world now uses the Roman alphabet.
Ancient Greece had one language and culture, but was not unified until 337 BC, when Macedonia defeated Athens and Thebes. That marked the end of the Classic period, and the start of the Hellenistic period. Even then, the conquered cities were merely joined to Philip II of Macedon's Corinthian League; they were not occupied, and ruled themselves.
Ancient Greece consisted of several hundred more-or-less independent city states. This was different from other societies, which were tribal, or kingdoms ruling over relatively large territories.
Undoubtedly the geography of Greece—divided and sub-divided by hills, mountains and rivers—contributed to the nature of ancient Greece. On the one hand, the ancient Greeks had no doubt that they were 'one people'; they had the same religion, same basic culture, and same language. Yet each city-state or "polis" was independent; unification was something rarely discussed by the ancient Greeks. Even when, during the second Persian invasion of Greece, a group of city-states allied themselves to defend Greece, most "poleis" remained neutral, and after the Persian defeat, the allies quickly returned to infighting.
The major features of the Ancient Greek political system were:
Later, in the Classical period, the leagues were fewer and larger, and dominated by one city (particularly Athens, Sparta and Thebes). Often cities would be compelled to join under threat of war (or as part of a peace treaty). After Philip II of Macedon 'conquered' the heartlands of ancient Greece, he did not attempt to annex the territory, or unify it into a new province. However, he did force most of the cities to join his own Corinthian League.
Some cities were democratic, some were aristocratic, and some were monarchies. Some had many revolutions in which one kind of government replaced another. One famous Greek kingdom is Macedon, which became briefly the largest empire the world had seen at the time by conquering the Persian empire (including ancient Egypt) and reaching into modern-day India. Other famous kingdoms are Epirus and Thessaly.
Monarchies in ancient Greece were not absolute because there was usually a council of older citizens ("the senate", or in Macedonia "the congress") who gave advice to the King. These men were not elected or chosen in a lottery like they were in the democratic city-states.
Citizens that could participate in government in Ancient Greece were usually men who were free-born in that city. Women, slaves and (usually) residents born elsewhere, did not have the right to vote. Details differed between cities. Athens is an example: The residents of Athens were of three groups: citizens, metics (resident aliens) and slaves. Citizens were residents whose forebears had been Athenians for three generations. Male citizens had the rights of free men and could be chosen to fulfill any official state position. "Of the estimated 150,000 residents of the city state of Attica, only about one fifth held the privilege of citizenship". Women who were citizens in Athens could not participate in political offices, but in Sparta they could.
The number of Greeks grew and soon they could not grow enough food for all the people. When this happened, a city would send people off to start a new city, known as a colony.
Because the terrain was rough, most travel was by sea. For this reason, many new cities were established along the coastline. First new cities were started in Anatolia (Asia Minor) and later along the Black Sea, in Cyprus, in southern Italy, in Sicily, and around what today is Benghazi in Libya. They even started a city, Naucratis, on the river Nile in Egypt. The cities of today, Syracuse, Naples, Marseille and Istanbul started as the Greek cities Syracusa, Neapolis, Massilia and Byzantium.
By the 6th century BC some cities became much more important than the others. They were Corinth, Thebes, Sparta, and Athens.
The Spartans were very well disciplined soldiers. They defeated the people who lived near them and those people had to farm the land for the Spartans. These "helots" had to give the Spartans part of the food they grew and so the Spartans did not have to work. Instead, they learned how to be better soldiers. There were not many Spartans but there were many helots. Spartan military strength controlled the helots. The Spartans had two hereditary kings who led them in war. At home they were also ruled by a group of old men called the Gerousia (the senate).
Athens became a democracy in 510 BC. The men came to a place in the center of the city and decided what to do. It was the first place in the world where the people decided what their country should do. They would talk and then vote on what to do at the Boule (the parliament). But the women did not vote. Athens had slaves. These slaves were owned by their masters and could be sold to someone else. The Athenian slaves were less free than the Spartan helots. Every year, Athenian citizens elected eight generals who led them in war.
In 499 BC, the Greek cities in Anatolia rebelled. They did not want Persia to rule them anymore. Athens sent 20 ships to fight the Persians on the sea. The Greeks in Anatolia were defeated. The Persian King, Darius decided to punish Athens. He sent soldiers and ships to fight Athens.
Athens asked for help from Sparta. Sparta wanted to help but could not; they had a religious festival at that time. Athens sent her soldiers against the Persian soldiers: at the Battle of Marathon (490 BC) they defeated the Persians. Then the help from Sparta came.
At the Battle of Thermopylae The Spartans were led by Leonidas, and resisted the huge Persian army. After a couple of days, a traitor called Ephialtes led the Persians around the pass behind the Greek army. Realising that defeat was inevitable, Leonidas released many of his men. Those who stayed knew it would be a fight to the death. Leonides kept elite "hoplites" (foot soldiers) who had living sons at home. There were also allied Thespians and Thebans who volunteered to stay.
On the third day, Leonidas led his 300 Spartan hoplites and their allies against Xerxes and his mighty army. The Spartan-led forces fought this Persian force to their deaths in order to block the pass long enough to keep Xerxes and his army occupied while the rest of the Greek army escaped.
After Thermopylae many Greeks wanted to go south to the Peloponnese. Because the Isthmus of Corinth, the way into the Peloponnese, is very narrow, many wanted to fight the Persians there.
Athens was north of Corinth and she had a navy. Athens' leader Themistocles wanted to fight the Persians by the island of Salamis. Xerxes decided to send his fleet against the Greek fleet before the Greek ships could go to the Peloponnese. The Greek fleet defeated the Persians at the Battle of Salamis. Xerxes then went home with many of his soldiers but a Persian army stayed in Greece. This army was defeated at the Battle of Platea in 479 BC.
After the Persians were defeated at Platea, the Spartans did very little. However, Persia was still dangerous. Athens asked the Greek cities on the islands in the Aegean and in Anatolia to join her. The cities agreed because they were afraid of Persia. These cities formed the Delian League and Athens was their leader. Many of the cities of the Delian League had to pay Athens tribute money. Athens used the money to build many ships and the Parthenon. Sparta was still strong on land, but Athens was stronger on the sea. Several times there was war between Athens and Sparta. Then Athens decided to send many ships to Sicily to fight against the city Syracuse. Sparta sent help to Syracuse, and Athens was defeated. None of the Athenian ships came back.
Now Sparta wanted to build ships to fight Athens. It took a long time for Sparta to defeat Athens, but then at the Battle of Aegospotami the Spartans destroyed most of Athens's ships. The Athenians used an advanced type of ship called triremes. These ships had their combat systems, and were propelled by oarsmen. On the front of the Trireme was a large bronze battering ram. The oarsmen would row the trireme at an enemy boat, and ram a hole into its hull. This was the most effective way for the trireme to destroy other boats. The soldiers (hoplites) on the trireme would board the enemy ship and capture it. Nevertheless, the Athenian fleet of triremes was destroyed in a battle in 405 BC. Athens surrendered the following year and the war was over.
Men, when not working, fighting or discussing politics, could (at festive times) go to Ancient Greek theatre to watch dramas, comedies or tragedies. These often involved politics and the gods of Greek mythology. Women were not allowed to perform in the theatre; male actors played female roles.
Women did domestic work, such as spinning, weaving, cleaning and cooking. They were not involved in public life or politics. Women from rich families however, had slaves to carry out domestic work for them.
The famous Olympic games were held at Olympia every four years. They were for men only, and women were not allowed to attend, even as spectators. The sports included running, javelin throwing, discus throwing and wrestling. The Games were unusual, because the athletes could come from any Greek city.
Another competition, the Heraean Games, was held for women. It was also held at Olympus at a different time from the men's event.
The rules for girls in Sparta were different from other cities. They were trained in the same events as boys, because Spartans believed that strong women would produce strong babies who would become future warriors. Their girl athletes were unmarried and competed nude or wearing short dresses. Boys were allowed to watch the athletes, in the hopes of creating marriages and offspring.
Later, in the Classical period, girls could compete in the same festivals as males.
Malaria is an infectious disease caused by a parasite: it is spread by the bite of an infected mosquito. People catch malaria when the parasite enters the blood. The parasite causes a deadly infection which kills many people each year (from 75 million cases in 1950s to 0.1 million cases in 1960s). However, due to the development of insecticide resistance among mosquitoes and other factors, it staged a comeback in the mid 1970s (6.47 million cases in 1976), and continues to prevail in endemic/subendemic proportions, so that 80% indian population lives in malaria risk areas.
Malaria is produced by 4 species of the protozoal parasite Plasmodium, is endemic in many tropical countries. It is one of the most common health problems. As per latest WHO estimates (2011)* between 149–274 (median 216) million clinical cases and ~ 0.655 million deaths occur globally due to malaria each year, 90% of which are in Africa. This amounts to one malaria death every minute. In India, the National Malaria Eradication Programme (NMEP), started in 1958, achieved near complete disappearance of the disease in 1960s (from 75 million cases in 1950s to 0.1 million cases in 1960s).
The parasite that causes malaria is a protozoan called 'Plasmodium'. Protozoa are organisms with only one cell, but they are not bacteria. Bacteria are smaller and simpler than protozoans.
People usually get malaria from the "Anopheles" or "Culex" mosquitoes : they are the vectors of the disease. The "Plasmodium" gets into people by the bites of mosquitoes. The "Plasmodium" is in the mosquito's special saliva. The mosquito's saliva injects an anticoagulant into the person to prevent their blood from clotting. The person is then infected with "Plasmodium" as a by-product. This makes the person have the disease we call malaria.
Only the female mosquito gives people malaria, because only the female mosquito consumes blood. The male mosquito lives on the nectar of flowers. The female uses blood as a source of protein for its eggs.
Some people do not get malaria from mosquitoes. A baby can get it while inside its mother. This is called "maternal-foetal transmission". People can also get malaria from a blood transfusion. This is when someone gives blood to another person. Another way people can catch malaria is by using a needle that someone with the disease used before them.
There are several species (kinds) of "Plasmodium" that cause malaria in humans:
"P. vivax" and "P. falciparum" cause the most malaria in people. "Falciparum" malaria is the worst kind, and kills the most people.
When "Plasmodium" enters the blood, they are then called "sporozoites". Sporozoites go to the liver, where they make many more sporozoites. Then they change into a different form of "Plasmodium". This form is the "merozoite". The merozoites go into the red blood cells, then they make many more merozoites.
The merozoites break out of the red blood cells again and again. When they do this, the person gets very sick, and shows symptoms of malaria. This happens every few days, and is called a paroxysm.
"P. vivax" and "P. ovale" can live in the liver for a long time. A person can look well, but still have the "Plasmodium" in the liver. This is called a "dormant phase". Weeks or months later, the "Plasmodium" can leave the liver to the blood, and the person will get sick again.
"P. falciparum" is the most dangerous type of malaria. It makes people sicker than those with other types of malaria, because there are more of them in the blood. Also, with "falciparum" malaria, the red blood cells are sticky. This makes the red blood cells block blood vessels. If blood vessels are blocked, this can hurt what the blood vessel brings blood to, and can hurt people's organs.
Pregnant women and children are hurt most by malaria. When they get malaria, they get sicker.
40% of people live in a place where there is malaria. Malaria is in these places:
Every year, 300 to 700 million people get malaria. It kills 1 million to 2 million people every year. 90% of the deaths occur in Africa. Most of the people who die from malaria are children. Even if children do not die, many have brain damage.
Many of these deaths might be stopped with medicine or mosquito control. But many of the places malaria may be found are in poor countries. These countries do not have enough money to stop the mosquitoes, or to give people medicine. Money, however, is not the only problem. A country must have an organised medical system to provide services. Many countries in central Africa have been disrupted by warfare and conflict between groups, and general unrest. Also, easy solutions to kill the parasites do not exist as they did 50 years ago. This is because the insects are resistant to many insecticides, and the "Plasmodium" parasite is highly resistant to quinine and most other common drugs. This is a normal evolutionary process: the chemicals weed out the non-resistant organisms, and the offspring of the few resistant organisms multiply.
Symptoms are changes in someone's body that are signs for a disease. Most people who get malaria get symptoms 10–30 days after they get infected (the "Plasmodium" gets in their blood.) But some people can get symptoms after only a week, and some may be infected with malaria and not have symptoms for a year.
The most common symptom of malaria is fever, when the body temperature is high. The fever from malaria usually comes very suddenly. The people who have malaria often feel like they had influenza.
Symptoms of malaria are:
Signs of malaria:
Complications are problems that happen because of a disease.
Pregnant women and young children have more complications. People who get malaria for the first time have more complications. "Falciparum" malaria has the most complications.
A clinical diagnosis is based on the signs and symptoms of a disease, it is a diagnosis made without medical testing. In the case of malaria one of the main symptoms which may lead to a clinical diagnosis of malaria is a fever.
Any clinical diagnosis of malaria should be confirmed by a trained professional based upon laboratory results as soon as it is possible.
A Malaria rapid diagnostic test is a blood test which can confirm a diagnosis of malaria in about twenty minutes. RDTs are not foolproof and have a number of drawbacks, and as such a negative rapid diagnostic test should not be accepted at face-value and follow-up with malaria microscopy is necessary.
To see if patients have malaria, doctors may do a blood test. This test is called a "Giemsa blood smear". Blood is put on a slide which is a thin piece of glass. The "Giemsa" stain is put on the slide. This stain helps doctors see the malaria. Then they look at the slide under a microscope. The "Plasmodium" is seen in the red blood cells.
People with different kinds of malaria need different medicines. The medicine that works for one kind of malaria may not for another kind. So it is very important to know which species of "Plasmodium" the person has.
If the species is not known, the person should be given medicine and care like they have "falciparum" malaria the worst kind.
It is also important to know "where" the person got malaria. "Plasmodium" in some places is resistant to some medicines. So the medicines to treat malaria in Africa are different from the medicines to treat malaria from South America.
Everywhere except New Guinea, the treatment is the same. In New Guinea most "P. vivax" is resistant to "chloroquine". It can be treated with quinine, but this medicine can make people sick. Everywhere else, non-"falciparum" malaria is treated with chloroquine.
Chloroquine kills the "Plasmodium" in the blood. But the "Plasmodium" in the liver is not killed by chloroquine. "P. vivax" and "P. ovale" both stay in the liver a "long" time. This is the "dormant phase". Another medicine must be given with chloroquine for "P. vivax" and "P. ovale". This is to kill the "Plasmodium" in the liver. The medicine used to kill malaria in the liver is "primaquine". In southeast Asia, some "P. vivax" is resistant to primaquine. Most other places, "primaquine" works very well.
Some people get very sick from "primaquine". So people have to be tested to see if they have G6PD-deficiency before they take "primaquine".
Falciparum is the worst kind of malaria. People with "falciparum" malaria should be treated in a hospital if they are:
Even people who are treated with medicines at home should stay with the doctor for 8 hours. This is to make sure they do not get sicker.It also makes sure they can take the medicines by mouth. Malaria does not start to become a life-threatening disease until it has been a couple of weeks after the bite without being treated.
"Falciparum" malaria also has more resistance to medicines. This makes it much harder to treat. "Falciparum" malaria is always treated with two or more medicines. Doctors choose the medicines by where in the world the person got malaria. Different places have "P. falciparum" that is resistant to different medicines.
The most important resistance is chloroquine-resistance. In some places in the world, "P. falciparum" is killed by chloroquine. In some places it is chloroquine-resistant. This means chloroquine does not kill it. In these places quinine can be used. Quinine is taken by mouth.
There are three ways to prevent malaria:
"Vector control" is one way to stop malaria. Vector means an organism that carries an infectious disease to another organism. For malaria, the vector is the "Anopheles" mosquito.
The most used method of vector control is pesticides. These are chemicals that kill the mosquito. The first pesticide used for vector control was DDT. DDT worked very well for vector control. It killed mosquitoes. It did not make people very sick at the time it was used. It did not cost very much money. Other chemicals for vector control had not been invented yet.
In many places mosquitoes became resistant to DDT. This meant that DDT did not work anymore in these areas. Scientists worried that DDT was making people and animals sick. It killed a lot of wildlife too. DDT also stays in the environment for a long time. For these reasons, people mostly use other chemicals for vector control. "Organophosphate" or "carbonate" pesticides are used, like "malathion" or "bendiocarb".
Vector control is not the only way to stop malaria. And DDT is not the only chemical that can be used for vector control. The best way to stop malaria is to use a combination of methods. In some places, DDT may be a useful part of a program to stop malaria. This is why DDT is still allowed to be used for controlling malaria.
The mosquito that carries malaria comes more at dawn (when the sun comes up) and dusk (when the sun goes down.) Be most careful at these times. Wear long trousers and shirts with long sleeves. Wear mosquito repellent (this is a chemical that mosquitoes do not like, so they do not bite.) Mosquitoes will bite through thin cloth. So repellent should be used on skin "and clothes".
Pesticides can be used in rooms to kill mosquitoes. When sleeping outside, people use a mosquito net. This is made from cloth that air can go through but keeps mosquitoes out. It is put over a bed where people sleep to keep mosquitoes out. Sometimes people also use it when they are not sleeping. It is best to use mosquito nets that have been treated with Permethrin, which repels and kills mosquitoes.
People can take medicine when they are in a place where there is malaria. This reduces the chances that they contract malaria. This is called "prophylaxis".
Some people take prophylactic medicines for years. Many people in areas where there is malaria do not have the money to buy this medicine.
People who live where there is no malaria usually have "not" had malaria. The first case malaria is usually much worse. So people from places where there is no malaria may take prophylactic medicines when they go to places where there is malaria. The kind of prophylactic medicines people take depends on where they are. This is because not all medicines work on the malaria in every place.
To make them work best, prophylactic medicines have to be taken the right way. The medicine should start "before" going to an area with malaria. Most medicines should be taken for 4 weeks after coming home. One medicine (Malarone) only needs to be used for "one" week after coming home.
There are some children in Tanzania who are naturally immune to malaria. Researchers are using this to develop a new vaccine. U.S. researchers have found the children produce an antibody which attacks the malaria-causing parasite. Injecting a form of this antibody into mice protected the animals from the disease. The researchers plan to do tests on primates, including humans.
It was Britain's Sir Ronald Ross, working in the Presidency General Hospital in the Kolkata, who finally proved in 1898 that malaria is transmitted by "anopheles" mosquitoes. He did this by showing that certain mosquito species transmit malaria to birds. He isolated malaria parasites from the salivary glands of mosquitoes that had fed on infected birds. For this work, Ross received the 1902 Nobel Prize in Medicine. After resigning from the Indian Medical Service, Ross worked at the newly established Liverpool School of Tropical Medicine and directed malaria-control efforts in Egypt, Panama, Greece and Mauritius. The findings of Finlay and Ross were later confirmed by a medical board headed by Walter Reed in 1900. Its recommendations were used during construction of the Panama Canal. This public-health work saved the lives of thousands of workers and helped develop the methods used in future public-health campaigns against the disease.
The first effective treatment for malaria came from the bark of cinchona tree, which contains quinine. This tree grows on the slopes of the Andes, mainly in Peru. The indigenous peoples of Peru made a tincture of cinchona to control malaria. The Jesuits noted the efficacy of the practice and introduced the treatment to Europe during the 1640s, where it was rapidly accepted. It was not until 1820 that the active ingredient, quinine, was extracted from the bark, isolated and named by French chemists.
In the early 20th century, before antibiotics became available, Julius Wagner-Jauregg discovered that patients with syphilis could be treated by intentionally infecting them with malaria. The resulting fever would kill the syphilis spirochaetes, and quinine could be administered to control the malaria. Although some patients died from malaria, this was preferable to the almost-certain death from syphilis.
Malaria was the largest hazard encountered by U.S. troops in the South Pacific during World War II, where about 500,000 men were infected. Sixty thousand American soldiers died of malaria during the North African and South Pacific campaigns.
Blood vessel
A blood vessel is a tube that carries blood in the circulatory system. Blood vessels that take blood away from the heart are arteries. Blood vessels that take blood back to the heart are veins. Capillaries are between veins and arteries and they supply tissue with blood.
The heart plus all of the blood vessels in the body together are called the circulatory system. Blood is moved by the pumping of the heart and carries oxygen to the tissues.
The expansion of blood vessels is called vasodilation, it helps the body to get rid of heat energy ("vas-" in Latin means "container" or "vessel").
The constriction of blood vessels is called vasoconstriction, it prevents the body from losing warmth.
There are 100,000 km (60,000 miles) of blood vessels in an adult human body.
Growing new blood vessels is called angiogenesis.
Different parts of the body have different kinds of blood vessels for different parts of their work. The vessel wall consists of three shells:
The structure of the vessel wall depends on hemodynamic conditions: blood flow velocity, volume and blood pressure. Arteries located close to the heart are characterized by a predominance of elastic elements that are able to counteract high hemodynamic parameters. As you move away from the heart, hemodynamic values decrease, the caliber of blood vessels decreases and the number of muscle elements in their walls increases, which are able to create additional force to push blood into the network of the smallest vessels.
"Jana Gana Mana" (जन-गण-मन) is the title for the national anthem of India. In 1911, it was composed and originally written in Bengali by popular Indic poet and artist Rabindranath Tagore—the same author for the Bangladeshi anthem ""Amar Shonar Bangla"". Originally a five-verse Brahmo hymn in Bengali called ""Bharoto Bhagyo Bidhata"", in January 1950, only the first verse was made to be officially part of the national anthem of India per the . In addition, the lyrics now contain many words of Sanskrit origin.
Circulatory system
The circulatory system (also called the cardiovascular system) is the body system that moves blood around the body. It consists of the heart and blood vessels. The blood carries various materials that the body needs, and takes away waste or harmful substances.
Blood vessels that take blood away from the heart are arteries. Arteries divide into smaller arteries as they go away from the heart. The smaller arteries that connect to the capillaries, are called "arterioles".
Blood vessels that take blood towards the heart are veins. Veins get bigger as they go towards the heart. The smallest veins are called "venules". Pronounced (VEHN-yools)
Capillaries go between arteries and veins. Capillaries are quite thin, hence the name which comes from the Latin "capillus" meaning "hair."
So blood moves: heart→artery→arteriole→capillary→venule→vein→heart. This is called circulation. There are two different "circulations" in the circulatory system. The "systemic circulation" is how blood goes to most of the body. The "pulmonary circulation" is how blood goes through the lungs. (Pulmonary means ¨about the lungs¨). This is how it works in mammals, including humans. Circulatory systems of other vertebrates differ somewhat.
Blood that comes from the left side of the heart is full of oxygen and nutrients. Nutrients are substances that your body needs to live, like protein, fat, carbohydrates, vitamins, and minerals. The blood brings the oxygen and nutrients to your body.
This blood in "systemic" arteries that is full of oxygen and nutrients is "systemic arterial blood". It is sometimes just called "arterial blood".
The biggest systemic artery in the body is the aorta. This is the large blood vessel that comes out of the heart. Smaller arteries branch off from the aorta. These arteries have smaller arteries that branch off from them. The smallest arteries turn into arterioles.
The smallest blood vessels are capillaries. Systemic arterioles turn into capillaries. The blood from arterioles goes into the capillaries. There oxygen and nutrients go out of the blood into the tissue around the capillaries. The blood also picks up carbon dioxide and waste from the tissue. The network of capillaries that brings blood to an area is called a "capillary bed".
On the other end of the capillary, it turns into a venule. Venules are the smallest veins. Veins take blood back to the heart. As veins go back to the heart, they merge and get bigger. The biggest systemic veins in the body are the vena cava. There are two vena cava. The "inferior vena cava" takes blood from the lower part of the body to the right side of the heart. (In anatomy, inferior means below.) The "superior vena cava" takes blood from the upper part of the body to the heart. (Superior means above.)
This same movement of blood goes through the lungs in the "pulmonary circulation".
The blood that the vena cava vein takes to the heart is full of carbon dioxide. It has much less oxygen than (systemic) arterial blood. The right side of the heart pushes the venous blood into the pulmonary artery. The pulmonary artery takes blood to the lungs. In the lungs, the blood goes through the "pulmonary capillary bed". (The capillaries that are in the lungs). Here it gets more oxygen. It also drops off carbon dioxide. (This is the opposite of what happens in capillary beds in the rest of the body. In the systemic circulation blood drops off oxygen and picks up carbon dioxide).
After the pulmonary capillary bed, the blood goes to the pulmonary veins. This "pulmonary venous blood" now is full of oxygen. The pulmonary veins take blood to the left side of the heart. Then the blood goes to the systemic circulation again.
Veins from the gut shunt to the liver before returning to the right atrium and ventricle. The shunt is called the hepatic portal vein.
The meaning of this is as follows. The liver is the body's main chemical factory. It takes in the flow of nutrients from the gut, and adjusts them to suit what the body needs. It can store surplus nutrients, or release extra nutrients from store. It can change the chemical make-up of many nutrients. In this way it adapts to the many different kinds of food which the body digests.
Pink triangle
The pink triangle is one of the two big symbols of the LGBT community. The other is the rainbow flag.
The pink triangle was first used in Nazi Germany to mark homosexual prisoners. There was also a "black triangle" that marked "anti-social women". Many but not all of these women were lesbians. Jews wore the famous yellow star of David. If a prisoner was both Jewish and gay, he would wear a yellow triangle overlapped by a pink triangle, creating a star of David.