Joseph Lister (1827-1912)

Joseph Lister is the surgeon who introduced new principles of cleanliness which transformed surgical practice in the late 1800s. We take it for granted that a surgeon will guard a patient's safety by using aseptic methods. But this was not always the case, and until Lister introduced sterile surgery, a patient could undergo a procedure successfully only to die from a postoperative infection known as ‘ward fever’.

Born in Essex, Lister was interested in surgery from an early stage - he was present at the first surgical procedure carried out under anaesthetic in 1846. Lister continued his studies in London and passed his examinations, becoming a fellow of the Royal College of Surgeons in 1852. He was recommended to visit Professor of Clinical Surgery James Syme (1799-1870) in Edinburgh and became his dresser, then house surgeon and then his son-in-law.

Lister moved to Glasgow in 1860 and became a Professor of Surgery. He read Pasteur'swork on micro-organisms and decided to experiment with using one of Pasteur's proposed techniques, that of exposing the wound to chemicals. He chose dressings soaked with carbolic acid (phenol) to cover the wound and the rate of infection was vastly reduced. Lister then experimented with hand-washing, sterilising instruments and spraying carbolic in the theatre while operating, in order to limit infection. His lowered infection rate was very good and Listerian principles were adopted throughout many countries by a number of surgeons. Lister is now known as the ‘father of antiseptic surgery’.

Antonie van Leeuwenhoek – known as the father of microbiology

1632–1723

Leeuwenhoek is well known for his contributions to microscopy, and how he applied this to the field of biology. He revolutionised a technique for creating powerful lenses, which some speculate were able to magnify up to 500 times. Leeuwenhoek used the microscopes to find out more about the living world – his discoveries include bacteria, the vacuole of the cell, and the banded pattern of muscle fibres.

The wacky history of cell theory

Scientific discovery isn't as simple as one good experiment. The weird and wonderful history of cell theory illuminates the twists and turns that came together to build the foundations of biology.
Here ther is a story by Lauren Royal-Woods.

View full lesson: http://ed.ted.com/lessons/the-wacky-h...

White Blood cells

White blood cells (WBCs), or leukocytes, are a part of the immune system and help our bodies fight infection. They circulate in the blood so that they can be transported to an area where an infection has developed. In a normal adult body there are 4,000 to 10,000 (average 7,000) WBCs per microliter of blood. When the number of WBCs in your blood increases, this is a sign of an infection somewhere in your body.

Here are the six main types of WBCs and the average percentage of each type in the blood:

• Neutrophils - 58 percent
• Eosinophils - 2 percent
• Basophils - 1 percent
• Bands - 3 percent
• Monocytes - 4 percent
• Lymphocytes - 4 percent

Most WBCs (neutrophils, eosinophils, basophils and monocytes) are formed in the bone marrow.

Cell theory.Introduction

This is the Video which tells the story of discovery of cell as a functional and structural unit of organism. The characters in the video are acting as Robert Hook, and other scientists....