Blood. Red cells

1. The average adult has five litres of blood pumping around their body. About 20 per cent of this blood is in the heart and arteries, whooshing out through the aorta at 45 centimetres per second for a person at rest. It reaches lows of just 0.5 millimetres per second as it branches out into the maze of tiny capillaries which deliver oxygen to cells, tissues and organs.

2. The blood picks up speed again to around 25 centimetres per second as it returns to the heart in larger veins. The average speed of blood in the body is 28 centimetres per second, which equals about 17,000 kilometres in a week. The reality is far more complicated as blood pressure and heart rate (linked to how active you are, among other factors) affect blood velocity dramatically.

3. Blood is red because it contains iron, bound up in a ring-like chemical structure called porphyrin within haemoglobin – the protein responsible for carrying oxygen around the body. Haemoglobin is crammed into our red blood cells, making them red too. Red blood cells are round with a flattish, indented center, like doughnuts without a hole. They play an important role in your health, remove carbon dioxide from your body, transporting it to the lungs for you to exhale. Red blood cells are made inside your bones, in the bone marrow (костный мозг). They typically live for about 120 days, and then they die.

Red blood cells, white blood cells and platelets (тромбоциты) are the key components of blood, floating in clear plasma, but the sheer volume of red blood cells gives blood a red colour overall.

4. Oxygen-rich blood is a bright red, whereas deoxygenated blood is a darker brownish red. The veins in your wrists (запястие) may appear blue but they are red too – the blue colour is the result of the way light travels through your skin. While all vertebrates (позвоночные) share the same colour blood, blue blood does exist – eg horseshoe crabs have no haemoglobin, having opted (выбрав) instead for haemocyanin, a copper-based (содержащий медь) protein.

Do you know any other animals with blue coloured blood?

Robert Hooke

Robert Hooke (1635-1703) was one of the most brilliant and versatile figures of his time. His own law, Hooke’s Law, has to do with elasticity, but he brought a piercing intelligence and inventiveness to bear on a remarkable range of fields – anatomy, astronomy, geometry and geology among them.

Hooke proved the rotation of Jupiter on its axis and determined the rotation period of Mars. He discovered that light rays bend round corners (diffraction) and put forward the wave theory of light to account for it. He investigated the action of the lungs and identified the role of air in combustion. He studied the crystal structure of snowflakes and the honeycomb structure of cork. He was interested in music and acoustics, and he designed balance springs for watches. He suggested the manufacture of artificial fibres by copying the action of silkworms. He examined fossils and tried vainly to get the history of the Earth examined in a non-Biblical light.

Stephen Inwood’s recent biography, The Man Who Knew Too Much, shows Hooke interested in virtually everything. He devised improved scientific instruments – thermometers, telescopes, microscopes, pendulums and pumps – as well as a pedometer, a marine barometer, a depth sounder and various navigational instruments. He made advances in the study of insects and lectured on the medicinal properties of cannabis. He worked on machines for making cider and measuring the wind. He considered the possibilities of flying machines, long-distance signalling systems and bouncing shoes, which would shoot the wearer twelve feet up in the air. Not content with all this, he was also a practising architect who worked with Christopher Wren on the rebuilding of the City of London after the Great Fire of 1666.

He  died a disappointed man.Because when Newton produced his theory of light and colour in 1672, Hooke claimed that what was correct in Newton's theory was stolen from his own ideas about light of 1665 and what was original was wrong. And this led to a bitter dispute with Newton. Hooke has been described as a:-... lean, bent and ugly man ... and so it was believed that he did not sit for a portrait. A possible portrait recently found at the Royal Society has now been established as being of someone else.

TED-Ed: Blood

Click the link below and see Diana's lesson about our blood.
Blood

To know more about blood follow the link How artificial blood works!
Follow the link and test your knowledge about blood Blood quiz.
Good luck!

Comment do you like this lesson?

Sexual reproduction

Vocabulary list

zygote - a single cell that develops into a person or animal, formed by the joining together of a male and a female gamete (= a cell that is provided by each parent)

blastula - a hollow sphere of cells

 

Animals that reproduce sexually begin life as a zygote. The zygote undergoes a series of divisions to form a blastula, a hollow ball of cells. The blastula folds in on itself, forming a single opening called a blastopore. The blastopore leads to a central tube that becomes the digestive tract. A protostome is an animal whose mouth is formed from the blastopore. A deuterstome is an animal whose anus is formed from the blastopore. The anus is the opening through which wastes leave the digestive tract.

During early development, the cells of most animal embryos differentiate into three layers, called germ layers. The endoderm is the innermost germ layer. The mesoderm is the middle germ layer. And the ectoderm is the outermost germ layer. 

  

Answer the questions:

What is the first stage  of a living being that starts his life as a result of sexual activity?

How is digestive tract formed?

Can you name three germ layers?

Unexpected Discoveries

Let’s review just a few of the important discoveries of the past couple of centuries that were made entirely by chance. 

In 1791 Luigi Galvani was an anatomist at the University of Bologna. Galvani was investigating the nerves in frog legs, and had threaded* some legs on copper wire hanging from a balcony in such a way that a puff of wind caused the legs to touch the iron railing. A spark snapped and the legs jerked violently (even today, we speak of being “galvanized” into action). In one unintentional step, Galvani had observed a closed electrical circuit*, and related electricity to nerve impulses. So he is typically credited with the discovery of bioelectricity. 

In 1879, Louis Pasteur inoculated some chickens with cholera bacteria. It was supposed to kill them, but Pasteur or one of his assistants had accidentally used a culture from an old jar and the chickens merely got sick and recovered. Later, Pasteur inoculated them again with a fresh culture that he knew to be virulent, and the chickens didn’t even get sick. Chance had led him to discover the principle of vaccination for disease prevention. 

Wilhelm Roentgen was experimenting with electrical discharges one evening at the University of Wurzburg in 1895. There was a screen coated with a barium compound lying to one side, and Roentgen noticed that it would fluoresce when an electrical discharge would occur in the tube he was watching. On reaching for the screen, Roentgen got his hand between the discharge tube and the screen and saw the bones of his own hand through the shadow of his skin. In 1901, Roentgen received the Nobel Prize for his accidental discovery of X-rays. 

Alexander Fleming was a young bacteriologist at St. Mary’s Hospital in London in 1928. One day in his laboratory, he noticed that a culture dish of bacteria had been invaded by a mould* whose spore must have drifted in through an open window. Under the microscope, he saw that, all around the mould, the individual bacteria that he had been growing had burst. He saved the mould, and from it produced the first penicillin. 

Although the mad scientists or eccentric inventors so often portrayed in old movies are still good for laughs, that’s not what we’re talking about here. Surely the need still exists for the imaginative and inventive experimenter. 

(Adapted from “Unexpected scientific discoveries are often the most important” )

Collocation

Collocation is the way words combine in a language to produce natural-sounding speech and writing. E.g., in English you say strong wind and heavy rain.
It would be not normal to say *heavy wind or *strong rain.

Collocation runs through the whole of the English language. No piece of natural spoken or written English is totally free of collocation.
For the student, choosing the right collocation will make his speech and writing more natural, more native-speaker-like.

Comment how many collocations you can make with the words discovery and invention.

International words vs “False friends”

The words mostly of Greek and Latin origin that are used in many other languages especially in different areas of science and technology are called international words, e.g. geometry, atom, mathematics, radio, integral, theorem, structure, etc.


Knowledge of such words helps a lot in reading and translation.
However, there are the so called ‘false friends”. These are words that look like international but have different meanings in English and in Russian, e.g. to reclaim (to take back something that was yours), actual (real, existing in fact, etc), spectacles (a pair of eyeglasses), etc.

Sort out the words below into categories. Consult a dictionary if necessary.

 International words vs “False Friends” 

Lecture, battery, detail, form, control, accurate, technology, massive, magazine, fact, logic, pioneer, mixture, nature, repetition, general, argument, prospect, affect, problem, actual, technique, intelligent, example, original, paragraph, transparent, focus, lamp, list, test, category, primitive, cyberspace, combination, activity, priority, sodium, application, fabric, metal, guarantee, industry, type, location, material, vibration, phenomenon, physician, data, encyclopedia, menu, clay, system, correspondent, probe, familiar, unique, scheme, lava, to speculate, cabinet. 

A guide to using diagrams

Lots of information to share? What about presenting information or a story visually? Would you like to make a diagram to organize visually your information? 

Above there isa guide how to do it.

Palm reading

Do you believe in palm reading?

 

Can you list your arguments pro and against?

Read the article to make it clear why some Japanese are having an operation to change the length and shape of the lines