Discovery history of pulmonary circulation

Until Ibn al-Nafis, the standard explanation of heart anatomy and function was from Galen who believed that blood move from the right ventricle to the left through a series of pores or passageways between the two sides.

In the thirteenth century, Ibn Nafis was practicing physician who studied medicine in Damascus. He was attached to the Mansuri Hospital in Cairo.

In his commentary on Avicenna’s Canon of Medicine, Ibn al-Nafis clearly describes the pulmonary circulation, although there is still reference to blood mixing with air to become ‘purified’.

Ibn al-Nafis clarified all that when he studied the heart lung blood circulation, observed through many surgeries and possibly disection. I

Ibn al-Nafis’ description of the lesser circulation was brought to light in 1924, by Muhyi ad-din at-Tatawi, who found it while examining some Arabic manuscripts in Berlin and presented it before the medical faculty of Freiburg as part of his doctoral thesis.

It wasn’t until 1553, that a clear description of pulmonary circulation was published in the West, in Christianismi Restitutio, written by Michael Servetus (1511-53), a polymath physician and Humanist.
Discovery history of pulmonary circulation

History of carbohydrate

The initial history of carbohydrates is the story of sugar cane and the human passion for sweetness.

Sugar cane’s origin is thought to be Papua New Guinea, cultivated from wild plants about 10000 years ago during Neolithic agricultural revolution.

Crystalline sugar from cane was known in India around 300 CE and the use of sugar spread via the caravan routes over North Africa into Spain around this time.

Joseph Louis Proust, who formulated the law of definite proportions, had studied the sugar juices of plants from 1799 to 1808 and had identified three different sugars: sucrose, fructose and glucose.

In 1792, a carbohydrate was isolated from honey which was different from cane sugar. In 1802, a sweet carbohydrate was found in grapes which were also different from sucrose.

In 1820, it was found that the same crystalline sugar could be obtained from the urine of diabetics and from the acid hydrolysis of cellulose.

The name glucose was coined by Dumas in 1838 for the sugar obtained from honey, grapes, starch and cellulose; 20 years later its molecular formula of C6H12O6 was established.

The name carbohydrate was first proposed in 1844 by German chemist, Carl Schmidt.

Chemically this is logical, since as the name implies, carbohydrates are compounds of carbon and hydrogen, together with oxygen.

In 1856, Liver glycogen, the animal storage form of carbohydrate, was discovered by French physiologist Claude Bernard.
History of carbohydrate